Battery cell and electric device

Abstract

The present application belongs to the field of secondary batteries. Disclosed are a battery cell and an electric device. The battery cell comprises a battery body and a housing for accommodating the battery body, wherein the battery body comprises a positive electrode sheet, an electrolyte, and a negative electrode sheet. When the battery cell is charged, metal ions are removed from the positive electrode sheet, and a metal is formed on the negative electrode sheet. The residual space inside the housing is 0.15-2 mL / Ah, the pressure inside the housing is less than or equal to 0.65 MPa, and the partial pressure P of hydrogen inside the housing is 0<P≤0.65 MPa. The battery cell further comprises a hydrogen storage material, the hydrogen storage material is provided between the battery body and the housing, and the hydrogen absorption platform pressure of the hydrogen storage material is less than or equal to 1 MPa. The battery cell of the present application comprises a hydrogen storage material, which can absorb hydrogen generated by the battery, reduces the risk of thermal runaway of the battery cell, reduces the internal pressure of the battery cell, and prolongs the service life of the battery cell.

Description

Battery cells and electrical equipment Technical Field

[0001] This application belongs to the field of secondary batteries, specifically relating to a battery cell and an electrical device. Background Technology

[0002] Secondary batteries are widely used in energy storage power systems such as hydropower, thermal power, wind power and solar power plants, as well as in many fields such as power tools, electric bicycles, electric motorcycles, electric cars, military equipment, and aerospace.

[0003] Battery cells have attracted widespread attention due to their high energy density. However, taking sodium metal batteries as an example, alkali metal sodium is formed during cycling. Alkali metal sodium is relatively reactive and can undergo side reactions with the electrolyte, producing a large amount of gas, with H2 accounting for >90% of the gas. This leads to hydrogen accumulation within the battery. When the hydrogen concentration reaches a certain level, there is a risk of thermal runaway, affecting the lifespan of the battery cell. Therefore, it is necessary to strictly control the hydrogen generated within the battery cell. Summary of the Invention

[0004] In view of the technical problems existing in the background art, this application provides a battery cell that aims to reduce the generation of hydrogen in the battery cell and reduce the risk of thermal runaway of the battery cell.

[0005] To achieve the above objectives, the first aspect of this application proposes a battery cell, comprising a battery body and a casing for housing the battery body. The battery body includes a positive electrode, an electrolyte, and a negative electrode. During charging, metal ions are released from the positive electrode and metal is formed on the negative electrode. The residual space inside the casing is 0.15 mL / Ah to 2 mL / Ah, the pressure inside the casing is ≤0.65 MPa, and the partial pressure P of hydrogen gas inside the casing is in the range of 0 < P ≤ 0.65 MPa. The battery cell also includes a hydrogen storage material disposed between the battery body and the casing, wherein the hydrogen absorption plateau pressure of the hydrogen storage material is less than or equal to 1 MPa.

[0006] This application includes at least the following beneficial effects: the battery cell of this application has a residual space inside the casing of 0.15 mL / Ah-2 mL / Ah, the pressure inside the casing is ≤0.65 MPa, the partial pressure P of hydrogen inside the casing is in the range of 0 < P ≤ 0.65 MPa, and the hydrogen absorption platform pressure of the hydrogen storage material is less than or equal to 1 MPa, which allows the hydrogen storage material to absorb the hydrogen produced by the battery cell, thereby reducing the internal pressure of the battery cell, reducing the risk of thermal runaway of the battery cell, and extending the life of the battery cell.

[0007] In some embodiments, the hydrogen absorption plateau pressure of the hydrogen storage material is 0.05 MPa-0.3 MPa, optionally 0.05 MPa-0.29 MPa. This reduces hydrogen generation in the battery cell, thereby extending the battery cell's lifespan.

[0008] In some implementations, 0 < P ≤ 0.35 MPa. This reduces hydrogen production in the battery cell, thereby extending the cell's lifespan.

[0009] In some embodiments, the pressure inside the casing is 0.05 MPa to 0.35 MPa. This reduces hydrogen production in the battery cells, thereby extending their lifespan.

[0010] In some embodiments, under standard conditions, each gram of the hydrogen storage material can absorb 50 mL to 250 mL of hydrogen gas. This reduces hydrogen production in the battery cell, thereby extending the battery cell's lifespan.

[0011] In some embodiments, under standard conditions, each gram of the hydrogen storage material can absorb 50 mL to 180 mL of hydrogen gas. This reduces hydrogen production in the battery cell, thereby extending the battery cell's lifespan.

[0012] In some embodiments, the hydrogen absorption pressure of the hydrogen storage material is 0.005 MPa to 0.5 MPa. This reduces hydrogen generation in the battery cell, thereby extending the battery cell's lifespan.

[0013] In some embodiments, the hydrogen absorption pressure of the hydrogen storage material is 0.005 MPa-0.1 MPa. This reduces hydrogen generation in the battery cell, thereby extending the battery cell's lifespan.

[0014] In some embodiments, the volume average particle size Dv50 of the hydrogen storage material is 2μm-50μm, optionally 2μm-30μm, and further optionally 10μm-20μm. This reduces hydrogen generation in the battery cell, thereby extending the battery cell's lifespan.

[0015] In some embodiments, the negative electrode sheet includes a negative current collector and an interface modification layer disposed on at least one side of the negative current collector, the interface modification layer including a first binder and a conductive agent. This can reduce hydrogen generation in the battery cell, thereby extending the battery cell's lifespan.

[0016] In some embodiments, the thickness of the interface modification layer is 0.5 μm-5 μm. This reduces hydrogen generation in the battery cell, thereby extending the battery cell's lifespan.

[0017] In some embodiments, the interface modification layer further includes the hydrogen storage material. This can reduce hydrogen generation in the battery cell, thereby extending the battery cell's lifespan.

[0018] In some embodiments, the negative electrode includes a negative current collector and an active material layer disposed on at least one side of the negative current collector, the active material layer comprising an elemental active metal. This reduces hydrogen production in the battery cell, thereby extending the battery cell's lifespan.

[0019] In some embodiments, the active metal is an elemental form including at least one of lithium, sodium, potassium, zinc, or aluminum. This reduces hydrogen production in the battery cell, thereby extending the battery cell's lifespan.

[0020] In some embodiments, the amount of hydrogen storage material added to the battery cell is 0.1 g / Ah to 2 g / Ah. This reduces hydrogen production in the battery cell, thereby extending its lifespan.

[0021] In some embodiments, the amount of hydrogen storage material added to the battery cell is 0.1 g / Ah to 0.75 g / Ah. This reduces hydrogen production in the battery cell, thereby extending its lifespan.

[0022] In some embodiments, the amount of hydrogen storage material added to the battery cell is 0.2 g / Ah to 0.5 g / Ah. This reduces hydrogen production in the battery cell, thereby extending its lifespan.

[0023] In some embodiments, the operating voltage of the battery cell is 1.5V-4V. This reduces hydrogen production in the battery cell, thereby extending its lifespan.

[0024] In some embodiments, the operating voltage of the battery cell is 1.5V-3V, and the amount of hydrogen storage material added is 0.02g / Ah-0.6g / Ah. This reduces the generation of hydrogen in the battery cell and extends its lifespan.

[0025] In some embodiments, the operating voltage of the battery cell is 1.5V-3V, and the amount of hydrogen storage material added is 0.07g / Ah-1.6g / Ah. This reduces the generation of hydrogen in the battery cell and extends its lifespan.

[0026] In some embodiments, the electrolyte includes a solvent, which includes at least one of ether solvents or ester solvents. This reduces hydrogen production in the battery cell, thereby extending the battery cell's lifespan.

[0027] In some embodiments, the solvent includes an ether solvent, comprising at least one of 1,2-dimethoxypropane, dimethoxymethane, ethylene glycol dimethyl ether, tetrahydrofuran, 2-methyltetrahydrofuran, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, pentaethylene glycol dimethyl ether, polyethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol diethyl ether, triethylene glycol diethyl ether, tetraethylene glycol diethyl ether, pentaethylene glycol diethyl ether, ethylene glycol dibutyl ether, diethylene glycol dibutyl ether, or 1,3-dioxane. This reduces hydrogen production in the battery cell, thereby extending the battery cell's lifespan.

[0028] In some embodiments, the electrolyte includes an electrolyte salt, wherein the molar concentration of the electrolyte salt is 0.5 mol / L to 4 mol / L. This can reduce the generation of hydrogen in the battery cell, thereby extending the battery cell's lifespan.

[0029] In some embodiments, the electrolyte comprises an electrolyte salt, wherein the molar concentration of the electrolyte salt is 0.5 mol / L to 1.5 mol / L. This reduces hydrogen production in the battery cell, thereby extending the battery cell's lifespan.

[0030] In some embodiments, the electrolyte comprises a liquid electrolyte, and the amount of liquid electrolyte injected into the battery cell is 2 g / Ah to 8 g / Ah. This reduces hydrogen production in the battery cell, thereby extending its lifespan.

[0031] In some embodiments, the electrolyte comprises a liquid electrolyte, and the amount of liquid electrolyte injected into the battery cell is 2.4 g / Ah to 6 g / Ah. This reduces hydrogen production in the battery cell, thereby extending its lifespan.

[0032] In some embodiments, the battery cell satisfies at least one of the following conditions: the BET specific surface area of ​​the hydrogen storage material is 0.5 m². 2 / g-10m 2 / g, optional 1m 2 / g-10m 2 / g; the tap density of the hydrogen storage material is 3 g / cm³. 3 -7g / cm 3 The compaction density of the hydrogen storage material is 4 g / cm³. 3 -8g / cm 3 The saturated aqueous solution of the hydrogen storage material has a pH of 9-11 at 25°C. This reduces hydrogen production in the battery cells, thereby extending their lifespan.

[0033] In some embodiments, the battery cell satisfies at least one of the following conditions: the hydrogen release plateau pressure of the hydrogen storage material is 1 MPa-1.5 MPa; under standard conditions, each gram of the hydrogen storage material can absorb 50 mL-250 mL of hydrogen gas; the density of the hydrogen storage material is 3 g / cm³. 2 -8.5g / cm 2 The hydrogen storage material has an operating temperature range of -40℃ to 60℃. This reduces hydrogen production in the battery cells, thereby extending their lifespan.

[0034] In some embodiments, the hydrogen storage material includes one or more of carbon-based materials and alloy materials. Therefore, the hydrogen storage material can absorb hydrogen gas produced by the battery cell, extending the battery cell's lifespan.

[0035] In some embodiments, the carbon-based material comprises porous carbon. Therefore, the carbon-based material can absorb hydrogen gas produced by the battery cell, extending the battery cell's lifespan.

[0036] In some embodiments, the alloy material includes zirconium alloys, magnesium alloys, titanium alloys, vanadium alloys, or La. x Ni y M z At least one of the following, wherein M includes at least one of Zr, Mn, Mg, Zn, Al, Ti, Fe, Cu, Co, Y, Ca, Bi, Ce, Pr, and Nd, and 0 < x ≤ 2, 0 ≤ y ≤ 7, and 0 ≤ z ≤ 3. This can reduce the generation of hydrogen in the battery cell, thereby extending the battery cell's lifespan.

[0037] In some embodiments, the alloy material satisfies at least one of the following conditions: (1) the titanium alloy includes at least one of TiNi, Ti2Ni, TiFe, or TiMn2; (2) the magnesium alloy includes at least one of Mg2Ni, Mg2Cu, Mg2Co, Mg2Al, Mg2Cr, or Mg2Te; (3) the zirconium alloy includes at least one of ZrV2, ZrCr2, or ZrMn2; (4) the vanadium alloy includes V3TiNi. 0.56 M1 m M = 0.046-0.24, and M1 includes at least one of Al, Si, Fe, Cu, or Zr. This reduces hydrogen production in the battery cell, thereby extending its lifespan.

[0038] In some implementations, the La x Ni y M z At least one of the following conditions must be met: (1) The La x Ni y M zIn the chemical formula, 0.3 ≤ x ≤ 1; (2) the La x Ni y M z In the chemical formula, 1≤y≤5; (3) the La x Ni y M z In the chemical formula, 0≤z≤1; (4) the La x Ni y M z In the chemical formula, M includes at least one of Al, Mn, Mg, Fe, Y, Bi, Ce, Pr, and Nd. Therefore, the above alloy material can absorb hydrogen gas produced by the battery cells, extending the lifespan of the battery cells.

[0039] In some embodiments, the hydrogen storage material includes LaNi 3.5 M2 x1 M3 y1 M4 z1 Where x1 is 0.2-0.6, y1 is 0-1, z1 is 0.3-0.9, x1+y1+z1=1.5, M2 includes at least one of Mn or Fe, M3 includes at least one of Zr, Ti or Y, and M4 includes at least one of Al, Mg, Ca or Bi. This reduces hydrogen production in the battery cell, thereby extending its lifespan.

[0040] In some embodiments, the hydrogen storage material includes La 0.5 Ni 4.5 Y 0.5 LaNi 3.5 Mn 0.2 YBi 0.3 LaNi 3.5 Mn 0.6 Y 0.4 Bi 0.5 LaNi 3.5 Mn 0.2 Y 0.4 Bi 0.9 LaTi 3.5 Fe 0.4 Zr 0.5 Bi 0.6 LaTi 3.5 Fe 0.4 Zr 0.5 Mg 0.6 LaNi 4.26 Al 0.08 Mg 0.16 La 0.43 Y 0.57 Ni 4.5 Al 0.08 Mn0.3 LaNi 3.97 Co 0.45 Mn 0.41 Al 0.24 LaNi 3.5 Al 0.13 At least one of them. Therefore, the generation of hydrogen in the battery cell can be reduced, thereby extending the battery cell's lifespan.

[0041] In some embodiments, the battery cell satisfies at least one of the following conditions: at 170°C, the water content in the battery cell is 200ppm-1000ppm; the positive electrode includes a positive current collector and a positive active material layer disposed on at least one side of the positive current collector, the positive active material layer includes positive active material, and based on the total mass of the positive active material, the mass percentage of residual alkali is 0.2%-1.5%. This reduces hydrogen generation in the battery cell, thereby extending the battery cell's lifespan.

[0042] In some embodiments, the battery cell includes a hydrogen storage material sheet, which comprises a substrate and a hydrogen storage material layer disposed on at least one side of the substrate, the hydrogen storage material layer comprising the hydrogen storage material. This reduces hydrogen generation in the battery cell, thereby extending its lifespan.

[0043] In some embodiments, the battery cell satisfies at least one of the following conditions: the mass percentage of the hydrogen storage material is ≥90% based on the total mass of the hydrogen storage material layer; the hydrogen storage material layer further includes a second binder, the second binder including at least one of polytetrafluoroethylene, polyacrylic acid, carboxymethyl cellulose, or styrene-butadiene rubber; the substrate includes at least one of copper, nickel, aluminum, or stainless steel; the thickness of the hydrogen storage material sheet is 0.1 mm-4.5 mm; the thickness of the hydrogen storage material layer is 0.05 mm-1.25 mm; and the thickness of the substrate is 10 μm-150 μm. This reduces hydrogen generation in the battery cell, thereby extending the battery cell's lifespan.

[0044] In some embodiments, the battery body includes: an electrode assembly (20) including the positive electrode and the negative electrode, the electrode assembly being housed within the housing (10), and a gap being formed between the electrode assembly (20) and the housing (10); an electrolyte comprising an electrolyte solution, the electrolyte solution being housed within the housing (10), a portion of the electrolyte solution being immersed within the electrode assembly (20), and a portion of the electrolyte solution being housed within a portion of the gap; and a gas storage structure (30) housed within the housing (10), the gas storage structure (30) being at least partially located in another portion of the gap, and at least a portion of the gas storage structure (30) being the hydrogen storage material.

[0045] In some embodiments, the housing (10) includes a first wall (10a) and a second wall (10b) disposed opposite to each other, the first wall (10a) supporting the electrode assembly (20), at least a portion of the gap being formed between the second wall (10b) and the electrode assembly (20), and at least a portion of the gas storage structure (30) being disposed between the electrode assembly (20) and the second wall (10b).

[0046] In some embodiments, a first insulating element (40a) is provided between the second wall (10b) and the electrode assembly (20);

[0047] The gas storage structure (30) is disposed between the first insulating member (40a) and the second wall (10b), and / or, the gas storage structure (30) is disposed between the first insulating member (40a) and the electrode assembly (20).

[0048] In some embodiments, the second wall (10b) faces the side surface of the first insulator (40a), and / or the side surface of the first insulator (40a) facing the second wall (10b) is connected to the gas storage structure (30), and / or the electrode assembly (20) faces the side surface of the first insulator (40a), and / or the side surface of the first insulator (40a) facing the electrode assembly (20) is connected to the gas storage structure (30).

[0049] In some embodiments, an electrode space is formed between the first insulating member (40a) and the electrode assembly (20), the electrode space accommodating the electrode (21), and at least a portion of the gas storage structure (30) is disposed within the electrode space.

[0050] In some embodiments, the tab space includes: a tab region (a) accommodating the tab (21) and a void region (b) located around the tab region (a), at least a portion of the gas storage structure (30) being disposed in the tab region (a), and / or the void region (b).

[0051] In some embodiments, the gas storage structure (30) is provided in the gap between adjacent tabs (21) in the tab region (a), and / or in the gap between the tab (21) and the outer shell (20).

[0052] In some embodiments, the first insulating member (40a) has a receiving cavity (41) that is open to the side facing the second wall (10b) and / or to the side facing the electrode assembly (20) to receive the gas storage structure (30), and the receiving cavity (41) is in communication with the gap.

[0053] In some embodiments, the first insulating member (40a) includes a limiting portion (42) that protrudes toward the electrode assembly (20), and the receiving cavity (41) is formed in the limiting portion (42).

[0054] In some embodiments, the second wall (10b) is provided with an explosion-proof element (14) configured to rupture when the pressure inside the housing (10) reaches a set condition to release gas inside the housing (10), the first insulating element (40a) has a connecting portion for connecting the internal space of the housing (10) with the explosion-proof element (14), and at least a portion of the gas storage structure (30) is disposed in the connecting portion.

[0055] In some embodiments, the connecting portion is configured as a connecting groove (c) formed on the first insulating member (40a), the connecting groove (c) extending along the side surface of the first insulating member (40a) facing the electrode assembly (20) to the side surface of the first insulating member (40a) away from the electrode assembly (20).

[0056] In some embodiments, the housing (10) is provided with a third wall (10c), which is connected to the first wall (10a) and the second wall (10b) respectively, and at least part of the gas storage structure (30) is disposed between the third wall (10c) and the electrode assembly (20).

[0057] In some embodiments, a second insulating member (40b) is provided between the third wall (10c) and the electrode assembly (20), and the gas storage structure (30) is disposed between the second insulating member (40b) and the third wall (10c), and / or, the gas storage structure (30) is disposed between the second insulating member (40b) and the electrode assembly (20).

[0058] In some embodiments, the third wall (10c) faces the side surface of the second insulator (40b), and / or the side surface of the second insulator (40b) facing the third wall (10c) is connected to the gas storage structure (30), and / or the electrode assembly (20) faces the side surface of the second insulator (40b), and / or the side surface of the second insulator (40b) facing the electrode assembly (20) is connected to the gas storage structure (30).

[0059] In some embodiments, the second insulating member (40b) has a receiving cavity (41) that is open to the side facing the third wall (10c) and / or to the side facing the electrode assembly (20) to receive the gas storage structure (30), and the receiving cavity (41) is in communication with the gap.

[0060] In some embodiments, the second insulating member (40b) includes a limiting portion (42) that protrudes toward the electrode assembly (20), and the receiving cavity (41) is formed in the limiting portion (42).

[0061] In some embodiments, a tab space is formed between the second insulating member (40b) and the electrode assembly (20), the tab space accommodating the tab (21), and at least a portion of the gas storage structure (30) is disposed within the tab space.

[0062] In some embodiments, the tab space includes: a tab region (a) accommodating the tab (21) and a void region (b) located around the tab region (a), with at least a portion of the gas storage structure (30) disposed in the void region (b).

[0063] In some embodiments, the gas storage structure (30) located between the third wall (10c) and the electrode assembly (20) is disposed adjacent to the second wall (10b), and the maximum distance between the gas storage structure (30) and the second wall (10b) is less than or equal to 5 mm.

[0064] In a second aspect of this application, an electrical device is provided, comprising the battery cell described in the first aspect of this application.

[0065] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0066] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiments below. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0067] Figure 1 is a schematic diagram of an electrical device according to an embodiment of this application;

[0068] Figure 2 is a schematic diagram of a battery device according to an embodiment of this application;

[0069] Figure 3 is a schematic diagram of a battery cell according to an embodiment of this application;

[0070] Figure 4 is a schematic diagram of the disassembly of a battery cell according to an embodiment of this application;

[0071] Figure 5 is a schematic diagram of the end cap according to the first embodiment of this application;

[0072] Figure 6 is a schematic diagram of a battery cell according to the first embodiment of this application;

[0073] Figure 7 is a cross-sectional view of a single battery cell according to the first embodiment of this application from one angle;

[0074] Figure 8 is a cross-sectional view of a battery cell according to the first embodiment of this application from another angle;

[0075] Figure 9 is a cross-sectional view of a single battery cell according to the first embodiment of this application from another angle;

[0076] Figure 10 is a schematic diagram of a battery cell according to the second embodiment of this application;

[0077] Figure 11 is a cross-sectional view of a single battery cell according to a second embodiment of this application from one angle;

[0078] Figure 12 is a schematic diagram of a battery cell according to the third embodiment of this application;

[0079] Figure 13 is a cross-sectional view of a battery cell according to a third embodiment of this application from one angle;

[0080] Figure 14 is a schematic diagram of a battery cell according to the fourth embodiment of this application;

[0081] Figure 15 is a cross-sectional view of a battery cell according to the fourth embodiment of this application from one angle;

[0082] Figure 16 is a schematic diagram of an end cap according to a fifth embodiment of this application;

[0083] Figure 17 is a cross-sectional schematic diagram of the end cap according to the fifth embodiment of this application;

[0084] Figure 18 is a schematic diagram of the end cap according to the sixth embodiment of this application;

[0085] Figure 19 is a cross-sectional schematic diagram of the end cap according to the sixth embodiment of this application;

[0086] Figure 20 is a schematic diagram of a battery cell according to the seventh embodiment of this application;

[0087] Figure 21 is a schematic diagram of the end cap according to the eighth embodiment of this application;

[0088] Figure 22 is a cross-sectional schematic diagram of the end cap according to the eighth embodiment of this application;

[0089] Figure 23 is a schematic diagram of a gas storage structure according to an embodiment of this application;

[0090] Figure 24 is a pressure-hydrogen content curve of the hydrogen storage material prepared in Example 1 of this application;

[0091] Figure 25 is an ion-polished cross-sectional morphology of the hydrogen storage material sheet prepared in Example 1 of this application;

[0092] Figure 26 is an internal pressure-time curve of the battery of Embodiment 1 and Comparative Example 1 of this application. Detailed Implementation

[0093] The embodiments of the technical solution of this application are described in detail below. The following embodiments are only used to illustrate the technical solution of this application more clearly, and are therefore only examples, and should not be used to limit the scope of protection of this application.

[0094] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0095] The "range" disclosed in this application is defined by a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, which define the boundaries of a particular range. Ranges defined in this way can include or exclude endpoints and can be arbitrarily combined; that is, any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60-120 and 80-110 are listed for a specific parameter, it is expected that ranges of 60-110 and 80-120 are also included. Furthermore, if minimum range values ​​of 1 and 2 are listed, and if maximum range values ​​of 3, 4, and 5 are listed, then the following ranges are all expected: 1-3, 1-4, 1-5, 2-3, 2-4, and 2-5. In this application, unless otherwise stated, the numerical range "ab" represents a shortened representation of any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "0-5" indicates that all real numbers between "0-5" have been listed in this article; "0-5" is simply a shortened representation of these numerical combinations. Furthermore, when a parameter is stated as an integer ≥2, it is equivalent to disclosing that the parameter is, for example, an integer such as 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0096] Unless otherwise specified, all embodiments and optional embodiments of this application can be combined to form new technical solutions.

[0097] Unless otherwise specified, all technical features and optional technical features of this application may be combined to form new technical solutions.

[0098] Unless otherwise specified, all steps in this application may be performed sequentially or randomly, preferably sequentially. For example, the method includes steps (a) and (b), indicating that the method may include steps (a) and (b) performed sequentially, or it may include steps (b) and (a) performed sequentially. For example, the mention that the method may also include step (c) indicates that step (c) may be added to the method in any order. For example, the method may include steps (a), (b), and (c), or it may include steps (a), (c), and (b), or it may include steps (c), (a), and (b), etc.

[0099] Currently, judging from market trends, the application of rechargeable batteries is becoming increasingly widespread. Rechargeable batteries are not only used in energy storage power systems such as hydropower, thermal power, wind power, and solar power plants, but also widely used in electric vehicles such as electric bicycles, electric motorcycles, and electric cars, as well as in military equipment and aerospace, among other fields.

[0100] When a battery cell is charged, metal ions are released from the positive electrode and metal is formed on the negative electrode. This refers to a battery that achieves cycling by depositing and consuming alkali metals on the negative electrode. Taking a sodium metal battery as an example, a layer of sodium metal can be pre-formed on the negative electrode during its preparation, or a sodium metal layer can be deposited during battery charging without pre-forming it. Because alkali metal sodium is formed during cycling, and sodium metal is relatively reactive, it will undergo side reactions with the electrolyte, producing a large amount of gas, and the proportion of H2 in the gas is >90%. Hydrogen gas remains inside the battery cell, which may pose a risk of thermal runaway.

[0101] Existing battery cells typically use vented top covers to expel hydrogen gas generated within the cell, thus protecting it. However, this approach has several drawbacks. First, different types of battery cells (such as lithium metal and sodium metal batteries) have varying chemical systems (electrolyte / positive electrode / negative electrode, etc.) and structural designs, resulting in significant differences in gas production rates and quantities. This necessitates vented top cover designs with varying permeability, increasing the manufacturing process and costs. Second, when multiple battery cells are assembled into battery modules or packs, the hydrogen gas from the individual cells, after being expelled through the vented top cover into the module or pack, poses a risk of fire, flash explosion, or ignition to the wiring harnesses inside. Third, the presence of the vented top cover means the battery cell is not a completely sealed system, making it susceptible to failure under special environments such as high temperature and high humidity. Moisture absorption can affect the cell's performance, and the vented top cover itself becomes the area with the lowest mechanical strength, making it prone to deformation and failure under pressure. All of these factors negatively impact the battery cell's lifespan.

[0102] The battery cell in this embodiment includes a battery body and a casing for housing the battery body. The residual space inside the casing is 0.15 mL / Ah-2 mL / Ah, the pressure inside the casing is ≤0.65 MPa, and the partial pressure P of hydrogen gas inside the casing is in the range of 0 < P ≤ 0.65 MPa. These characteristics of the battery cell all affect hydrogen absorption. To address these characteristics, the hydrogen absorption plateau pressure of the hydrogen storage material is controlled to be less than or equal to 1 MPa. Because the hydrogen storage material can absorb a large amount of hydrogen gas generated by the battery cell under this plateau pressure, and the aforementioned plateau pressure can be adapted to the battery cell, making it easier for the hydrogen storage material to absorb hydrogen gas within the battery cell. The hydrogen absorption plateau pressure is achieved so that hydrogen can be absorbed even at low pressure levels, i.e., when hydrogen is scarce. The amount of hydrogen absorbed and the absorption rate are far higher than those of a vented top cover, which can reduce the internal pressure of the battery cell, reduce the risk of thermal runaway, and extend the battery cell's lifespan. Furthermore, this application incorporates hydrogen storage materials within the battery cell, which can directly absorb the hydrogen produced by the battery cell. This is applicable to various types of battery cells, and the probability of hydrogen produced by the battery cell escaping into the battery module or battery pack is low, further reducing the risk of thermal runaway. It also reduces the battery cell's sensitivity to moisture, improves the battery cell's mechanical strength, and further extends its lifespan. In summary, the battery cell of this application embodiment can reduce the internal pressure of the battery cell, reduce the risk of thermal runaway, and extend the cycle life of the battery cell.

[0103] The battery cells disclosed in this application can be used in electrical devices that use batteries as a power source or in various energy storage systems that use batteries as energy storage elements. Electrical devices may include, but are not limited to, mobile phones, tablets, laptops, electric toys, power tools, electric vehicles, electric cars, ships, spacecraft, etc. Electric toys may include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Spacecraft may include airplanes, rockets, space shuttles, and spacecraft, etc.

[0104] The first aspect of this application discloses a battery cell, which includes a battery body and a casing for housing the battery body. The battery body includes a positive electrode, an electrolyte, and a negative electrode. During charging, metal ions are released from the positive electrode and metal is formed on the negative electrode. The residual space inside the casing is 0.15 mL / Ah to 2 mL / Ah, the pressure inside the casing is ≤0.65 MPa, and the partial pressure P of hydrogen gas inside the casing is in the range of 0 < P ≤ 0.65 MPa. The battery cell also includes a hydrogen storage material, and the hydrogen absorption plateau pressure of the hydrogen storage material is less than or equal to 1 MPa.

[0105] The battery cell in this embodiment includes a battery body and a casing for housing the battery body. The residual space inside the casing is 0.15 mL / Ah-2 mL / Ah, the pressure inside the casing is ≤0.65 MPa, and the partial pressure P of hydrogen gas inside the casing is in the range of 0 < P ≤ 0.65 MPa. These characteristics of the battery cell all affect hydrogen absorption. To address these characteristics, the hydrogen absorption plateau pressure of the hydrogen storage material is controlled to be less than or equal to 1 MPa. Because the hydrogen storage material can absorb a large amount of hydrogen gas generated by the battery cell under this plateau pressure, the aforementioned hydrogen absorption plateau pressure is suitable for the battery. The single-cell design allows the hydrogen storage material to more easily reach the hydrogen absorption plateau pressure within the battery cell. This enables the hydrogen storage material to absorb a large amount of hydrogen produced by the battery, reducing the internal pressure of the battery cell, lowering the risk of thermal runaway, and extending the battery cell's lifespan. Furthermore, the hydrogen storage material incorporated into the battery cell can directly absorb the hydrogen produced by the cell, making it applicable to various types of battery cells. The probability of the produced hydrogen being discharged into the battery module or battery pack is low, further reducing the risk of thermal runaway. It also reduces the battery cell's sensitivity to moisture, improves the battery cell's mechanical strength, and further extends its lifespan.

[0106] It is understood that when the battery cell is charged, metal ions are released from the positive electrode and metal is formed on the negative electrode. This refers to a battery that achieves cycling by depositing and consuming alkali metals at the negative electrode. When preparing the negative electrode, an alkali metal layer may be formed or may not (a battery without a negative electrode). In addition, the active metal of the battery cell may not be limited to lithium, sodium, and potassium, but may also include other active metals such as zinc and aluminum.

[0107] It is understandable that hydrogen storage materials refer to materials that can absorb hydrogen gas, including but not limited to physical adsorption materials and chemical adsorption materials. Chemical adsorption materials are those that can react with hydrogen gas to absorb it. Under standard conditions, any material that can absorb more than 5 mL of hydrogen gas can be considered a hydrogen storage material. Taking alloy materials as an example, the reaction process between alloy materials and hydrogen gas is as follows: First, hydrogen gas is catalytically decomposed into hydrogen atoms on the surface of the hydrogen storage material. Then, the hydrogen atoms enter the interior of the hydrogen storage material lattice to form metal hydrides, thus achieving the purpose of hydrogen storage.

[0108] It is understood that in the embodiments of this application, when the internal pressure of the battery cell is relatively small, the hydrogen absorption platform pressure of the hydrogen storage material can be reached. By controlling the hydrogen absorption platform pressure of the hydrogen storage material to be low, the energy barrier for the combination of metal elements in the hydrogen storage material with hydrogen atoms in the hydrogen gas is low. After the combination of each alloy element in the hydrogen storage material with hydrogen atoms in the hydrogen gas, the structure of the hydrogen storage material is stable after combining with hydrogen in the hydrogen gas.

[0109] Understandably, the material composition of hydrogen storage materials can be determined using an X-ray diffractometer.

[0110] In some embodiments of this application, the hydrogen absorption plateau pressure of the hydrogen storage material is less than or equal to 1 MPa. For example, the hydrogen absorption plateau pressure of the hydrogen storage material can be 0.1 MPa-0.98 MPa, 0.2 MPa-0.8 MPa, 0.3 MPa-0.7 MPa, 0.4 MPa-0.6 MPa, etc. The hydrogen absorption plateau pressure is the pressure value on the hydrogen absorption curve (PCT curve) where the pressure slowly increases with the hydrogen concentration (the slope of the curve decreases to <2), which is the pressure when the hydrogen storage material absorbs a large amount of hydrogen. Specifically, by controlling the hydrogen absorption plateau pressure of the hydrogen storage material within the above range, the low hydrogen absorption plateau pressure of the hydrogen storage material allows hydrogen to be absorbed at low pressure levels, i.e., when there is very little hydrogen, further reducing the hydrogen content in the battery cell, reducing the internal pressure of the battery cell, and extending the life of the battery cell.

[0111] In other embodiments of this application, the hydrogen absorption plateau pressure of the hydrogen storage material is 0.16 MPa-0.29 MPa. At this pressure, the hydrogen content in the gas produced by the battery cell is relatively high. For example, when the battery cell includes a sodium metal battery, the hydrogen content in the gas produced is high. Controlling the hydrogen absorption plateau pressure of the hydrogen storage material within this range further facilitates the effective absorption of large amounts of hydrogen, reduces the internal pressure of the battery cell, and lowers the risk of thermal runaway in the battery cell.

[0112] It is understood that the "hydrogen absorption plateau pressure of the hydrogen storage material" can be determined using methods known in the art, such as the following methods:

[0113] The battery cells were disassembled to obtain hydrogen storage materials (if the hydrogen storage materials exist in the form of hydrogen storage material sheets, the hydrogen storage material sheets were powdered and calcined at 500℃ to decompose the binder). The performance of the hydrogen storage materials was tested using an H2PCT-1153 3-channel fully automated hydrogen storage material performance testing system (Yangzhou Yinghui Zhiyue).

[0114] Pressure sensors: 2 full-range absolute pressure sensors (0-10MPa) and 1 sensor (0-15MPa), with an accuracy of 0.04%FS; Temperature sensors: RT-100℃, RT-300℃, RT-500℃; The furnace can be programmed to heat up; The temperature sensors are placed outside the sample chamber; The sample chamber volume is (H15mm×12mm); The sample chamber and test pipeline are connected via quick connectors.

[0115] PCT curves and hydrogen absorption kinetics of hydrogen storage materials were tested.

[0116] The gas cylinders consist of three 1000ml cylinders and three 150ml cylinders. The entire pipeline can withstand a pressure of 1×10⁻⁶. -6The hydrogen pressure is -15 MPa. The vacuum pump used is an Edwards vacuum pump (equipped with a hose, and the exhaust gas is discharged outdoors).

[0117] It is understood that the hydrogen storage material in this application embodiment can be placed at any location in the battery cell. This application does not impose any restrictions. The specific location will be described in detail below.

[0118] In some embodiments of this application, the battery cell includes a battery body and a casing for housing the battery body. The battery body includes the positive electrode, the electrolyte, and the negative electrode. The hydrogen storage material is disposed between the battery body and the casing. Thus, the hydrogen storage material does not affect the operation of the battery body, and no additional space is needed to house it. The hydrogen storage material can rapidly absorb hydrogen gas when it is generated, reducing the internal pressure of the battery cell, lowering the risk of thermal runaway, and extending the battery cell's lifespan.

[0119] In some embodiments of this application, the residual space inside the casing is 0.15 mL / Ah-2 mL / Ah, for example, it can be 0.15 mL / Ah-1.99 mL / Ah, 0.2 mL / Ah-1.45 mL / Ah, 0.5 mL / Ah-1.4 mL / Ah, 1 mL / Ah-1.35 mL / Ah, etc. It can be understood that the residual space inside the casing refers to the volume of gas remaining inside the casing of the battery cell, excluding the liquid and solid phases. The liquid phase is mainly the electrolyte, and the solid phase includes the positive electrode... In addition to the electrode plates, negative electrode plates, and separator, the casing also includes other components such as adapter plates, Mylar plates, bottom support plates, top mounting plates, aluminum nails, and plastic nails. By controlling the residual space inside the casing within the above range, it can effectively protect the battery body, provide space for the hydrogen storage material, and ensure that the inside of the casing reaches the hydrogen absorption pressure range of the hydrogen storage material. This increases the speed at which the hydrogen storage material absorbs hydrogen, reduces the risk of the generated hydrogen being immediately discharged from the battery cell, lowers the internal pressure of the battery, and extends the life of the battery cell. It can also reduce the decrease in the energy density of the battery cell caused by excessive residual space.

[0120] It is understood that "residual space inside the shell" is a well-known definition in the art and can be measured using methods known in the art. For example, it can be measured using the following methods:

[0121] Centrifuge the battery cell, pour out the electrolyte to obtain the electrolyte volume V1, then fill it with the same electrolyte to obtain the electrolyte volume V2. The residual space inside the casing = (V2-V1) / capacity of the battery cell.

[0122] In some embodiments of this application, the internal pressure of the outer casing is ≤0.65MPa, for example, it can be 0-0.64MPa, 0.05MPa-0.6MPa, 0.1MPa-0.4MPa, 0.2MPa-0.3MPa, etc. Controlling the internal pressure of the outer casing within this range can effectively and promptly absorb the hydrogen gas generated by the battery cells, maintain a low internal pressure inside the battery, and extend the life of the battery cells. In other embodiments of this application, the internal pressure of the outer casing is 0.05MPa-0.35MPa.

[0123] It is understood that "pressure inside the shell" is a well-known definition in the art and can be measured using methods known in the art. For example, it can be measured using the following methods:

[0124] The pressure was measured using a barometric pressure sensor.

[0125] In some embodiments of this application, the partial pressure P of hydrogen gas inside the casing is in the range of 0 < P ≤ 0.65 MPa, for example, it can be 0.01 MPa-0.64 MPa, 0.1 MPa-0.5 MPa, 0.2 MPa-0.3 MPa, etc. Controlling the partial pressure of hydrogen gas inside the casing within this range makes it easier for the hydrogen storage material to reach the hydrogen absorption plateau pressure within the battery cell. The hydrogen storage material can absorb a large amount of hydrogen gas generated by the battery, which can reduce the internal pressure of the battery cell, reduce the risk of thermal runaway of the battery cell, and extend the life of the battery cell. In other embodiments of this application, 0 < P ≤ 0.35 MPa.

[0126] It is understood that "the partial pressure P of hydrogen inside the shell" is a well-known definition in the art and can be measured using methods known in the art. For example, it can be measured using the following methods:

[0127] The gas inside the shell is passed into a mass spectrometer, and the molar percentage of hydrogen is measured. Then, the partial pressure of hydrogen inside the shell, P, is equal to the molar percentage of hydrogen multiplied by the pressure inside the shell.

[0128] In some embodiments of this application, under standard conditions, each gram of the hydrogen storage material can absorb 50 mL to 250 mL of hydrogen gas. For example, under standard conditions, the volume of hydrogen gas absorbed by each gram of the hydrogen storage material can be 50 mL to 240 mL, 100 mL to 200 mL, 150 mL to 179 mL, 155 mL to 175 mL, 160 mL to 170 mL, 165 mL to 170 mL, etc. This allows the hydrogen storage material to absorb a relatively large amount of hydrogen, thus enabling sufficient absorption of hydrogen generated by the battery cells even with a low amount of hydrogen storage material added, reducing the internal pressure of the battery cells, and extending their lifespan. In other embodiments, under standard conditions, each gram of the hydrogen storage material can absorb 50 mL to 180 mL of hydrogen gas.

[0129] As you can understand, standard temperature and pressure (STP), or simply "standard conditions" or "STP", refers to the conditions at 0°C and 101.325 kPa.

[0130] It is understood that "the volume of hydrogen that can be absorbed per gram of the hydrogen storage material under standard conditions" is a well-known definition in the art and can be determined using methods known in the art, such as the following methods:

[0131] The battery cell was disassembled to obtain the hydrogen storage material (if the hydrogen storage material exists in the form of hydrogen storage material sheets, the sheets were powdered and calcined at 500℃ to decompose the binder). 1g of the hydrogen storage material was added to a stainless steel sample chamber. The alloy was charged with hydrogen at a constant 5MPa hydrogen pressure for 2 hours. Then, the sample was evacuated for 30 minutes. This hydrogen charging-evacuation process was repeated at least three times to fully activate the hydrogen storage material.

[0132] The amount of hydrogen absorbed by the alloy was determined using the H2PCT-1153 three-channel fully automated hydrogen storage material performance testing system (Yangzhou Yinghui Zhiyue).

[0133] In some embodiments of this application, the hydrogen absorption pressure of the hydrogen storage material is 0.005 MPa-0.5 MPa, for example, it can be 0.005 MPa-0.49 MPa, 0.01 MPa-0.45 MPa, 0.1 MPa-0.4 MPa, or 0.2 MPa-0.3 MPa. It can be understood that the hydrogen absorption pressure refers to the pressure at which the hydrogen storage material can absorb hydrogen gas, which is the effective absorption range of hydrogen gas. That is, within the range of 0.005 MPa-0.5 MPa, the hydrogen storage material can absorb hydrogen gas. Controlling the hydrogen absorption pressure of the hydrogen storage material within this range can fully absorb the hydrogen gas generated by the battery cell, reduce the internal pressure of the battery cell, and extend the life of the battery cell. In other embodiments of this application, the hydrogen absorption pressure of the hydrogen storage material is 0.005 MPa-0.1 MPa.

[0134] It is understood that the "hydrogen absorption pressure of hydrogen storage materials" can be measured using methods known in the art, such as the following methods:

[0135] The same method for determining the hydrogen absorption platform pressure can be used to measure the PCT curve of the hydrogen storage material to obtain its hydrogen absorption pressure.

[0136] In some embodiments of this application, the BET specific surface area of ​​the hydrogen storage material is 0.5 m². 2 / g-10m 2 / g, for example, could be 0.5m 2 / g-9.9m 2 / g, 0.7m 2 / g-9m 2 / g, 1m 2 / g-8m 2 / g, 2m 2 / g-7m 2 / g, 3m 2 / g-6m 2 / g, 4m 2 / g-5m 2 / g, etc., in some other embodiments of this application, the BET specific surface area of ​​the hydrogen storage material is 1m². 2 / g-10m 2 By controlling the BET specific surface area of ​​the hydrogen storage material within the above range, the hydrogen storage material can fully contact and react with hydrogen, easily absorb hydrogen, and reduce the risk of combustion and explosion caused by excessive specific surface area of ​​the hydrogen storage material. It can effectively absorb hydrogen generated during the cycle of the battery cell, reduce the internal pressure of the battery cell, and extend the life of the battery cell.

[0137] The BET specific surface area in this application is determined by the specific surface area meter-static volumetric method with reference to the standard GB / T 19587-2017. Specifically, according to the embodiments of this application, a flow method gas adsorption type specific surface area measuring device can be used for measurement.

[0138] In some embodiments of this application, the volume average particle size Dv50 of the hydrogen storage material is 2μm-50μm, for example, it can be 2μm-49μm, 5μm-45μm, 10μm-40μm, 15μm-35μm, 20μm-30μm, 25μm-30μm, etc. In other embodiments of this application, the volume average particle size Dv50 of the hydrogen storage material is 2μm-30μm, for example, 10μm-20μm. Specifically, by controlling the volume average particle size Dv50 of the hydrogen storage material within the above range, the hydrogen storage material can fully contact and react with hydrogen, easily absorb hydrogen, and reduce the risk of combustion and explosion caused by excessively small particle size of the hydrogen storage material. It can effectively absorb hydrogen generated during the cycle of the battery cell, reduce the internal pressure of the battery cell, and extend the life of the battery cell.

[0139] It is understood that the volume average particle size Dv50 refers to the particle size corresponding to a cumulative volume distribution percentage of 50%. The volume average particle size Dv50 of hydrogen storage materials can be determined using methods known in the art, for example, by the following methods:

[0140] The battery cell is disassembled to obtain the hydrogen storage material (if the hydrogen storage material exists in the form of hydrogen storage material sheets, the hydrogen storage material sheets are scraped into powder and calcined at 500℃ to decompose the binder). The volume average particle size Dv50 of the hydrogen storage material is tested using a laser particle size analyzer (e.g., Malvern Master Sizer 3000) in accordance with the standard GB / T 19077-2016.

[0141] In some embodiments of this application, the tap density of the hydrogen storage material is 3 g / cm³. 3 -7g / cm 3 For example, it could be 3g / cm 3 -6.9g / cm 3 3.5g / cm 3 -6.5g / cm 3 4g / cm 3 -6g / cm 3 4.5g / cm 3 -5.5g / cm 3 By controlling the tap density of the hydrogen storage material within the above range, the hydrogen storage material can effectively absorb the hydrogen generated during the cycle of the battery cell, reduce the internal pressure of the battery cell, and extend the life of the battery cell.

[0142] It is understood that, unless otherwise specified, the tap density of the hydrogen storage material in this application can be determined with reference to the standard GB / T 5162-2006. Specifically, according to the embodiments of this application, the tap density can be measured using a Dandong Baite BT-303 metal powder tap density meter.

[0143] In some embodiments of this application, the compaction density of the hydrogen storage material is 4 g / cm³. 3 -8g / cm 3 For example, it could be 4g / cm³ 3 -7.9g / cm 3 4.5g / cm 3 -7.5g / cm 3 5g / cm 3 -7g / cm 3 5.5g / cm 3 -6.5g / cm 3 By controlling the compaction density of the hydrogen storage material within the above range, the hydrogen storage material can effectively absorb the hydrogen generated during the cycle of the battery cell, reduce the internal pressure of the battery cell, and extend the life of the battery cell.

[0144] It is understood that, unless otherwise specified, the compaction density of the powder in this application can be determined with reference to the standard GB / T 24533-2009. Specifically, it can be determined using a powder compaction density meter. More specifically, according to the embodiments of this application, it can be measured using the Yuaneng Technology PRCD3100 powder resistivity & compaction density meter.

[0145] In some embodiments of this application, the saturated aqueous solution of the hydrogen storage material has a pH value of 9-11 at 25°C, for example, it can be 9-10.9, 9.5-10.5, 9.8-10, etc. Controlling the pH value of the saturated aqueous solution of the hydrogen storage material at 25°C within the above range can reduce the probability of the hydrogen storage material absorbing water vapor, thereby reducing its reaction with water and failure. The hydrogen storage material can effectively absorb hydrogen gas generated during the cycle of the battery cell, reduce the internal pressure of the battery cell, and extend the life of the battery cell.

[0146] It is understood that the "pH value of a saturated aqueous solution of a hydrogen storage material at 25°C" in this application has a meaning known in the art and can be measured using instruments and methods known in the art. For example, it can be obtained by the following method:

[0147] The battery cell was disassembled to obtain the hydrogen storage material (if the hydrogen storage material exists in the form of hydrogen storage material sheets, the hydrogen storage material sheets were scraped into powder and calcined at 500℃ to decompose the binder). The hydrogen storage material was mixed with pure water at a mass ratio of 1:9 and magnetically stirred for 30 minutes. Then, it was placed in a constant temperature water bath at 25℃ and allowed to stand for 1.5 hours. The pH value of the mixture was tested according to GB / T 9724-2007.

[0148] In some embodiments of this application, the hydrogen release plateau pressure of the hydrogen storage material is 1 MPa to 1.5 MPa. The hydrogen release plateau pressure refers to the pressure value on the hydrogen release curve (PCT curve) where the pressure suddenly and slowly decreases (the slope of the curve decreases) as the hydrogen concentration decreases. For example, the hydrogen release plateau pressure of the hydrogen storage material can be 1 MPa to 1.49 MPa, 1.1 MPa to 1.4 MPa, 1.2 MPa to 1.3 MPa, etc. By controlling the hydrogen release plateau pressure of the hydrogen storage material within these ranges, a higher hydrogen release plateau pressure, i.e., a higher hydrogen release plateau pressure, can prevent the release of absorbed hydrogen, forming an irreversible hydrogen storage material, reducing the probability of absorbed hydrogen being released back into the battery cell, reducing the internal pressure of the battery cell, and extending the battery cell's lifespan.

[0149] It is understood that the "hydrogen release plateau pressure of the hydrogen storage material" can be determined using methods known in the art, such as the following methods:

[0150] Methods for determining the pressure of the hydrogen absorption platform.

[0151] In some embodiments of this application, the density of the hydrogen storage material is 3 g / cm³. 2 -8.5g / cm 2 For example, the density of hydrogen storage materials can be 3 g / cm³. 2 -8.4g / cm 2 4g / cm 2 -8.3g / cm 2 5g / cm 2 -8.2g / cm 2 6g / cm 2 -8.1g / cm 2 7g / cm 2 -8g / cm 2 By controlling the density of hydrogen storage materials within the above range, the hydrogen absorption capacity of the materials can be improved, allowing for the full absorption of hydrogen produced by the battery cells, reducing the internal pressure of the battery cells, and extending their lifespan. Furthermore, it can reduce the impact of excessively high density on the energy density of the battery cells.

[0152] It is understood that the "density of hydrogen storage materials" is a well-known definition in the art and can be determined using methods known in the art, such as the following methods:

[0153] The battery cells were disassembled to obtain hydrogen storage materials (if the hydrogen storage materials exist in the form of hydrogen storage material sheets, the hydrogen storage material sheets were scraped into powder and calcined at 500°C to decompose the binder), and the true density was measured using an INSTRUQUEST IQIPYC true density meter from the United States.

[0154] In some embodiments of this application, the operating temperature of the hydrogen storage material is -40℃ to 60℃. For example, the operating temperature of the hydrogen storage material can be -40℃ to 59℃, -30℃ to 50℃, -20℃ to 40℃, -10℃ to 30℃, 0℃ to 20℃, 10℃ to 15℃, etc. Specifically, the operating temperature of the hydrogen storage material refers to the temperature at which the hydrogen storage material can absorb hydrogen gas. Controlling the operating temperature of the hydrogen storage material within the above range allows the battery to adapt to low-temperature and high-temperature operating environments, reduces the internal pressure of the battery cell, and extends the life of the battery cell. In other embodiments of this application, the operating temperature of the hydrogen storage material is 0℃ to 45℃.

[0155] In some embodiments of this application, the hydrogen storage material includes one or more of carbon-based materials and alloy materials. Therefore, the aforementioned hydrogen storage material has a strong hydrogen absorption capacity, a high hydrogen absorption volume, and strong stability after absorbing hydrogen, making it less prone to releasing hydrogen again.

[0156] In some embodiments of this application, the carbon-based material includes porous carbon. Therefore, porous carbon can physically adsorb hydrogen gas, exhibiting high hydrogen adsorption capacity, strong stability after hydrogen absorption, and minimal re-release of hydrogen gas.

[0157] In some embodiments of this application, the alloy material includes zirconium alloys, magnesium alloys, titanium alloys, vanadium alloys, or La. x Ni y M z At least one of the following, wherein M includes at least one of Zr, Mn, Mg, Zn, Al, Ti, Fe, Cu, Co, Y, Ca, Bi, Ce, Pr, and Nd, and 0 < x ≤ 2, 0 ≤ y ≤ 7, and 0 ≤ z ≤ 3.

[0158] As an example, x can be 0.1-1.9, 0.3-1.7, 0.5-1.5, 0.8-1.3, 1-1.2, etc., and in some other embodiments of this application, 0.3≤x≤1.

[0159] y can be 1-6.9, 2-6, 3-5, etc. In some other embodiments of this application, 1≤y≤5.

[0160] z can be 0.1-2.9, 0.5-2.5, 1-2, etc., and in some other embodiments of this application, 0≤z≤1.

[0161] Among the aforementioned elements, Ti and Co can improve the lifespan and kinetics of hydrogen storage materials, Mg can increase the hydrogen absorption capacity of hydrogen storage materials, Mn and Al can construct the framework of hydrogen storage materials and reduce costs, Y can reduce the hydrogen absorption plateau pressure of hydrogen storage materials, Fe, Ca and Bi can increase the hydrogen release plateau pressure of hydrogen storage materials, and Fe can increase the hydrogen absorption plateau pressure of hydrogen storage materials, while Cu can increase the hydrogen absorption rate of hydrogen storage materials.

[0162] In other embodiments of this application, M includes at least one of Al, Mn, Mg, Fe, Y, Bi, Ce, Pr, and Nd.

[0163] The aforementioned hydrogen storage materials are characterized by rapid hydrogen absorption, large hydrogen absorption capacity, wide hydrogen absorption boundary, and small volume expansion. They have excellent hydrogen absorption capacity, can absorb hydrogen generated by the battery, reduce the internal pressure of the battery cell, reduce the risk of thermal runaway of the battery cell, and extend the life of the battery cell.

[0164] It is understandable that zirconium alloys refer to alloys containing zirconium, magnesium alloys refer to alloys containing magnesium, titanium alloys refer to alloys containing titanium, and vanadium alloys refer to alloys containing vanadium.

[0165] In some embodiments of this application, the titanium alloy includes at least one of TiNi, Ti2Ni, TiFe, or TiMn2. The above-mentioned titanium alloy has excellent hydrogen absorption capacity, which can absorb hydrogen gas generated by the battery, reduce the internal pressure of the battery cell, reduce the risk of thermal runaway of the battery cell, and extend the life of the battery cell.

[0166] In some embodiments of this application, the magnesium alloy includes at least one of Mg2Ni, Mg2Cu, Mg2Co, Mg2Al, Mg2Cr or Mg2Te. The above-mentioned magnesium alloy has excellent hydrogen absorption capacity, which can absorb hydrogen gas generated by the battery, reduce the internal pressure of the battery cell, reduce the risk of thermal runaway of the battery cell, and extend the life of the battery cell.

[0167] In some embodiments of this application, the zirconium alloy includes at least one of ZrV2, ZrCr2, or ZrMn2. The zirconium alloy has excellent hydrogen absorption capacity, which can absorb hydrogen generated by the battery, reduce the internal pressure of the battery cell, reduce the risk of thermal runaway of the battery cell, and extend the life of the battery cell.

[0168] In some embodiments of this application, the vanadium alloy includes V3TiNi. 0.56 M1 m The vanadium alloy with the above chemical formula has excellent hydrogen absorption capacity. It can absorb hydrogen gas generated by the battery, reduce the internal pressure of the battery cell, reduce the risk of thermal runaway of the battery cell, and extend the life of the battery cell.

[0169] In some embodiments of this application, the hydrogen storage material includes LaNi. 3.5 M2 x1 M3 y1 M4 z1 Where x1 is 0.2-0.6, y1 is 0-1, z1 is 0.3-0.9, x1+y1+z1=1.5, M2 includes at least one of Mn or Fe, M3 includes at least one of Zr, Ti or Y, and M4 includes at least one of Al, Mg, Ca or Bi.

[0170] As an example, x1 can be 0.2-0.59, 0.3-0.5, 0.4-0.45, etc., y1 can be 0-0.9, 0.1-0.8, 0.2-0.7, 0.3-0.6, 0.4-0.5, etc., and z1 can be 0.3-0.8, 0.4-0.7, 0.5-0.6, etc.

[0171] Specifically, lanthanide alloys have stable crystal structures and do not undergo other side reactions when reacting with hydrogen. Furthermore, the differences in atomic radii and electronegativity of different elements in the aforementioned hydrogen storage materials affect the cell volume of the hydrogen storage material and the interaction force between hydrogen and metal atoms. Based on the differences in atomic radii and electronegativity of different elements, and through the combined action with transition metal atoms, the embodiments of this application can increase the hydrogen absorption capacity of the hydrogen storage material, reduce the initial hydrogen absorption pressure, and improve the hydrogen release kinetics performance.

[0172] As an example, doping with transition metal M2 can reduce the hysteresis of hydrogen storage materials, while M3 and M4 can reduce the hydrogen absorption pressure of hydrogen storage materials, making it easier for them to absorb hydrogen. For instance, the doping element Ti has a particularly significant effect on improving the activation performance of hydrogen storage materials because Ti reacts with hydrogen before other phases during activation to form the TiH2 phase, causing cracks in the hydrogen storage material and making it easier for hydrogen to enter the interior, effectively reducing the activation energy of the hydrogen storage material. Through the combined effect of the above elements, the hydrogen storage capacity of the alloy can be increased, the initial hydrogen absorption pressure can be reduced, and the hydrogen release kinetics can be improved, making it easier for the hydrogen storage material to absorb hydrogen and less likely to release it, thereby reducing the hydrogen content in the battery cell, reducing the internal pressure of the battery cell, and extending the battery cell's lifespan.

[0173] In some embodiments of this application, the hydrogen storage material includes La 0.5 Ni 4.5 Y 0.5 LaNi 3.5 Mn 0.2 YBi 0.3 LaNi 3.5 Mn 0.6 Y 0.4 Bi 0.5 LaNi 3.5 Mn 0.2 Y 0.4 Bi 0.9 LaTi 3.5 Fe 0.4 Zr 0.5 Bi 0.6 LaTi 3.5 Fe 0.4 Zr 0.5 Mg 0.6 LaNi 4.26 Al 0.08 Mg 0.16 La 0.43 Y 0.57 Ni 4.5 Al 0.08 Mn 0.3 LaNi 3.97 Co 0.45 Mn 0.41 Al0.24 LaNi 3.5 Al 0.13 At least one of the above. The hydrogen storage material has excellent hydrogen storage capacity, low hydrogen absorption plateau pressure and high hydrogen release plateau pressure, which can effectively absorb hydrogen generated during the cycle of the battery cell, reduce the internal pressure of the battery cell and extend the life of the battery cell.

[0174] Specifically, in the above-mentioned hydrogen storage materials, at least one of Y or Fe elements is used, which can reduce the hydrogen absorption plateau pressure of the hydrogen storage material. The molar ratio of La element to other elements is less than 1:5. The high content of La element results in a large amount of hydrogen absorption and a lower hydrogen absorption plateau pressure of the hydrogen storage material.

[0175] This application does not limit the preparation method of the above-mentioned hydrogen storage material. As an example, the preparation method of the above-mentioned hydrogen storage material may be: mixing the metal elements corresponding to each element of the hydrogen storage material in the molar ratio shown in the chemical formula, heating and melting them under air-isolated conditions, and cooling them to obtain the hydrogen storage material.

[0176] [Electrolytes]

[0177] This application does not impose specific restrictions on the type of electrolyte; it can be selected according to requirements. For example, the electrolyte can be liquid, gel, or completely solid.

[0178] In some embodiments of this application, the electrolyte is an electrolyte solution. The electrolyte solution includes an electrolyte salt and a solvent.

[0179] In some embodiments of this application, the electrolyte includes a solvent, which includes at least one of ether solvents or ester solvents. It is understood that ether solvents refer to organic solvents containing ether groups, and ester solvents refer to organic solvents containing ester groups. Ether solvents and ester solvents have good compatibility with the hydrogen storage material of the embodiments of this application, and during the cycling process of the battery cell, hydrogen gas is generated, which is absorbed by the hydrogen storage material, reducing the internal pressure of the battery cell and extending its lifespan.

[0180] In some embodiments of this application, the solvent includes ether solvents, which include at least one of 1,2-dimethoxypropane, dimethoxymethane, ethylene glycol dimethyl ether, tetrahydrofuran, 2-methyltetrahydrofuran, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, pentaethylene glycol dimethyl ether, polyethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol diethyl ether, triethylene glycol diethyl ether, tetraethylene glycol diethyl ether, pentaethylene glycol diethyl ether, ethylene glycol dibutyl ether, diethylene glycol dibutyl ether, or 1,3-dioxane. The above-mentioned ether solvents are compatible with various battery cells, especially battery cells, and have good compatibility with the hydrogen storage material of the embodiments of this application. During the cycling process of the battery cell, hydrogen gas is generated, which is absorbed by the hydrogen storage material, reducing the internal pressure of the battery cell and extending the battery cell's lifespan.

[0181] In some embodiments of this application, the ester solvent may include at least one selected from ethylene carbonate, propylene carbonate, methyl ethyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, butyl carbonate, fluoroethylene carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1,4-butyrolactone, sulfolane, dimethyl sulfone, methyl ethyl sulfone, or diethyl sulfone.

[0182] In some embodiments of this application, the electrolyte comprises an electrolyte salt, wherein the molar concentration of the electrolyte salt is 0.5 mol / L-4 mol / L. For example, it can be 0.5 mol / L-3.9 mol / L, 1 mol / L-3.5 mol / L, 1.5 mol / L-3 mol / L, 2 mol / L-2.5 mol / L, etc. Controlling the concentration of the electrolyte salt within this range results in high ionic conductivity of the electrolyte, and the generated hydrogen gas is sufficient for absorption by the hydrogen storage material in the battery cell, further improving the cycle life of the battery cell. In other embodiments of this application, the molar concentration of the electrolyte salt is 0.5 mol / L-1.5 mol / L.

[0183] It is understood that "the molar concentration of electrolyte salts in an electrolyte" is a well-known definition in the art and can be determined using methods known in the art, such as the following methods:

[0184] The content of key elements such as lithium or sodium in the electrolyte was tested using elemental analysis-inductively coupled plasma atomic emission spectrometry.

[0185] In some embodiments of this application, when the battery is a lithium-ion battery, the electrolyte salt may include at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluorooxalate borate, lithium dioxalate borate, lithium difluorodioxalate phosphate, or lithium tetrafluorooxalate phosphate.

[0186] In some embodiments of this application, when the battery is a sodium-ion battery, the electrolyte salt may include at least one of sodium chloride, sodium bromide, sodium nitrate, sodium perchlorate, sodium hexafluorophosphate, sodium acetate, sodium trifluoroacetate, sodium trifluoromethanesulfonate, sodium bis(fluorosulfonyl)imide, sodium bis(trifluoromethanesulfonyl)imide, sodium tetrafluoroborate, sodium tetraphenylborate, sodium difluorooxalateborate, sodium dioxalateborate, and sodium hexafluoroarsenate.

[0187] In some embodiments of this application, the electrolyte may optionally include additives. For example, additives may include negative electrode film-forming additives, positive electrode film-forming additives, and may also include additives that can improve certain battery performance, such as additives that improve battery overcharge performance, additives that improve battery high-temperature or low-temperature performance, etc.

[0188] In some embodiments of this application, the electrolyte includes an electrolyte solution, and the amount of electrolyte injected into the battery cell is 2 g / Ah-8 g / Ah. The amount of electrolyte injected refers to the mass of electrolyte injected into the battery cell per unit Ah, for example, it can be 2 g / Ah-7.9 g / Ah, 3 g / Ah-7 g / Ah, 4 g / Ah-6 g / Ah, etc. Controlling the amount of electrolyte injected within this range ensures sufficient wetting of the positive electrode, separator, and other components in the battery cell, and that the generated hydrogen gas is sufficient to be absorbed by the hydrogen storage material, thereby reducing the internal pressure of the battery and extending the lifespan of the battery cell. In other embodiments of this application, the amount of electrolyte injected into the battery cell is 2.4 g / Ah-6 g / Ah.

[0189] It is understood that "the volume of electrolyte injected" is a well-known definition in the art and can be determined using methods known in the art, such as the following methods:

[0190] Weigh the battery cell to obtain m1. After centrifuging the battery, disassemble it, remove the electrolyte, and weigh it again to obtain m2. Then the electrolyte injection volume = (m1-m2) / battery cell capacity.

[0191] [Negative electrode plate]

[0192] In some embodiments of this application, the negative electrode sheet includes a negative current collector and an active material layer disposed on at least one side of the negative current collector, wherein the active material layer includes an elemental active metal. It is understood that an active metal refers to a metal capable of providing active metal ions. For example, the active metal in a lithium metal battery is elemental lithium, and the active metal in a sodium metal battery is elemental sodium. In this case, the battery cell includes an alkali metal battery. Specifically, a battery cell refers to a battery with an active metal as the negative electrode, such as lithium metal or sodium metal. In the above-mentioned types of battery cells, the active metal ions on the negative electrode sheet, such as lithium and sodium, are relatively active and will undergo side reactions with water, solvents in the electrolyte, and residual alkali in the positive electrode active material, resulting in a large amount of gas production, with H2 accounting for >90% of the gas. For the above-mentioned batteries where the main gas produced is hydrogen, by setting a hydrogen storage material in the battery, the hydrogen produced in the battery is absorbed, reducing the excessive internal pressure of the battery cell, with better results. The cycle life of the above-mentioned battery cells is significantly improved.

[0193] In some embodiments of this application, the active metal is an elemental form including at least one of lithium, sodium, potassium, zinc, or aluminum. That is, the battery cell includes at least one of lithium metal battery, sodium metal battery, potassium metal battery, zinc metal battery, or aluminum metal battery. The active metal ions in these battery cells are relatively reactive and will undergo side reactions with the electrolyte, producing a large amount of gas, with H2 comprising >90% of the gas. For batteries where the main gas produced is hydrogen, incorporating hydrogen storage materials within the battery absorbs the generated hydrogen, reducing excessive internal pressure within the battery cell, resulting in a significantly improved cycle life.

[0194] It is understood that in this application, the active metal is the metal formed on the negative electrode by metal ions released from the positive electrode during charging of the battery cell, as mentioned above.

[0195] In some embodiments of this application, the active material layer comprises an alloy formed of an active metal, and the lithium metal battery comprises a lithium metal alloy with the chemical formula LiR, wherein R comprises at least one of tin, zinc, aluminum, magnesium, silver, gold, gallium, indium, platinum, boron, carbon, or silicon.

[0196] In some embodiments of this application, when a lithium metal negative electrode sheet is used, the preparation method is as follows: lithium foil or lithium metal alloy is coated onto the current collector by single-sided rolling, and then cut into negative electrode sheets.

[0197] In some other embodiments of this application, the sodium metal battery includes a sodium metal alloy with the chemical formula NaR1, wherein R1 includes at least one of tin, zinc, aluminum, magnesium, silver, gold, gallium, indium, platinum, boron, carbon, or silicon.

[0198] In some other embodiments of this application, when a sodium metal negative electrode sheet is used, the preparation method is as follows: sodium foil or sodium metal alloy is coated onto the current collector by single-sided rolling, and then cut into negative electrode sheets.

[0199] In some embodiments of this application, the negative electrode sheet includes a negative current collector and an interface modification layer disposed on at least one side of the negative current collector. The interface modification layer includes a first binder and a conductive agent. That is, the negative electrode sheet does not contain alkali metal, and the prepared battery is called a negative electrode-free battery. The setting of the interface modification layer can make the active metal (alkali metal) uniformly deposited on the surface of the interface modification layer, thereby improving the cycle performance of the battery.

[0200] It's understandable that a "negative electrode-free battery" refers to a battery where no negative electrode active material is added during the battery manufacturing stage. However, a negative electrode current collector is still present. A negative electrode-free battery is simply a special type of battery cell (such as lithium metal batteries or sodium metal batteries); it doesn't truly lack a negative electrode. In actual operation, the negative electrode still contains active metals (such as lithium metal or sodium metal). The negative electrode in a negative electrode-free battery includes a bare negative electrode current collector (such as copper). Taking lithium batteries as an example, during battery charging, active metal ions such as Li... + The lithium metal is extracted from the positive electrode and deposited on the negative electrode current collector to form a lithium negative electrode. During subsequent battery discharge, the deposited lithium metal dissolves and is reinserted into the positive electrode.

[0201] In some embodiments of this application, the thickness of the interface modification layer is 0.5 μm-5 μm. For example, it can be 0.5 μm-4.9 μm, 1 μm-4 μm, 2 μm-3 μm, etc. Controlling the thickness of the interface modification layer within the above range can further enable the active metal (alkali metal) to be uniformly deposited on the surface of the interface modification layer, thereby improving the cycle performance of the battery.

[0202] It is understood that the "thickness of the interface modification layer" is a well-known definition in the art and can be measured using methods known in the art, such as the following methods:

[0203] The battery cell is disassembled, the negative electrode is removed, and the ion polished cross-sectional morphology (CP) image of the negative electrode is obtained using a scanning electron microscope. The thickness of the interface modification layer is measured at more than 5 locations selected from the image, and the average value is taken to obtain the thickness of the interface modification layer.

[0204] In some embodiments of this application, the interface modification layer further includes the hydrogen storage material. That is, the hydrogen storage material is disposed on the negative electrode sheet. The hydrogen storage material can immediately absorb hydrogen gas generated in the battery cell, and it does not participate in the reaction, exhibiting strong stability. This effectively reduces the internal pressure of the battery and improves its lifespan.

[0205] In some embodiments of this application, the negative electrode sheet includes a negative current collector and a negative active material layer disposed on at least one side of the negative current collector.

[0206] As an example, the negative electrode current collector has two surfaces opposite each other in its own thickness direction, and the negative electrode active material layer is disposed on either or both of the two opposite surfaces of the negative electrode current collector.

[0207] In some embodiments of this application, the negative electrode current collector may be a metal foil or a composite current collector. For example, copper foil may be used as the metal foil. The composite current collector may include a polymer material substrate and a metal layer formed on at least one surface of the polymer material substrate. The composite current collector may be formed by forming a metal material (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE), etc.).

[0208] In some embodiments of this application, the first adhesive may be selected from at least one of styrene-butadiene rubber (SBR), polyacrylic acid (PAA), sodium polyacrylate (PAAS), polyacrylamide (PAM), polyvinyl alcohol (PVA), sodium alginate (SA), polymethacrylic acid (PMAA), and carboxymethyl chitosan (CMCS).

[0209] In some embodiments of this application, the conductive agent may be selected from at least one of superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers.

[0210] In some embodiments of this application, the negative electrode active material layer may optionally include other additives, such as thickeners (e.g., sodium carboxymethyl cellulose (CMC-Na)).

[0211] In some embodiments of this application, the negative electrode sheet can be prepared by dispersing the above-mentioned components for preparing the negative electrode sheet, such as conductive agent, binder and any other components, in a solvent (e.g., deionized water) to form a negative electrode slurry; coating the negative electrode slurry onto the negative electrode current collector, and then obtaining the negative electrode sheet after drying, cold pressing and other processes.

[0212] In some embodiments of this application, at 170°C, the water content in the battery cell is 200ppm-1000ppm, for example, it can be 200ppm-990ppm, 300ppm-900ppm, 400ppm-800ppm, 500ppm-700ppm, etc. By controlling the water content of the battery cell within the above range, the hydrogen storage material in the battery cell is sufficient to absorb the hydrogen gas it generates, which can reduce the internal pressure of the battery cell and improve the life of the battery cell.

[0213] It is understood that "the water content in a single battery cell at 170°C" is a well-known definition in the art and can be determined using methods known in the art, such as the following methods:

[0214] The Karl Fischer coulometric method was used for determination.

[0215] [Positive electrode plate]

[0216] In some embodiments of this application, the positive electrode sheet includes a positive current collector and a positive active material layer disposed on at least one side of the positive current collector. The positive active material layer includes positive active material, and the mass percentage of residual alkali is 0.2%-1.5% based on the total mass of the positive active material. For example, the mass percentage of residual alkali can be 0.2%-1.4%, 0.3%-1.3%, 0.4%-1.2%, 0.5%-1.1%, 0.6%-1%, 0.7%-0.9%, etc. By controlling the residual alkali content in the positive active material within the above range, the hydrogen storage material in the battery cell is sufficient to absorb the generated hydrogen gas, which can reduce the internal pressure of the battery cell and improve the lifespan of the battery cell.

[0217] It is understandable that residual alkali refers to the substance formed by the reaction of the positive electrode active material with moisture and carbon dioxide in the air. Taking a sodium battery cell as an example, its residual alkali can include sodium hydroxide, sodium carbonate, sodium bicarbonate, etc. The mass percentage of residual alkali in the positive electrode active material can be determined by the following methods:

[0218] Taking sodium-alkali metal batteries as an example, the battery cell is disassembled to obtain the positive electrode sheet. The positive electrode sheet is calcined to deactivate the binder, resulting in the positive electrode active material. The free sodium in the positive electrode active material is tested by free Na potentiometric titration, and then the residual alkali content is calculated.

[0219] In some embodiments of this application, the positive electrode sheet includes a positive current collector and a positive active material layer disposed on at least one side of the positive current collector, wherein the positive active material layer includes the aforementioned irreversible positive electrode additive.

[0220] As an example, the positive current collector has two surfaces opposite each other in its own thickness direction, and the positive active material layer is disposed on either or both of the two opposite surfaces of the positive current collector.

[0221] In some embodiments of this application, the positive current collector may be a metal foil or a composite current collector. For example, aluminum foil may be used as the metal foil. The composite current collector may include a polymer material substrate and a metal layer formed on at least one surface of the polymer material substrate. The composite current collector may be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE), etc.).

[0222] In some embodiments of this application, when the battery is a lithium metal battery, the positive electrode active material may be a positive electrode active material known in the art for lithium-ion batteries.

[0223] As an example, the positive electrode active material may include at least one of the following materials: lithium phosphates with an olivine structure, lithium transition metal oxides, and their respective modified compounds. However, this application is not limited to these materials, and other conventional materials that can be used as positive electrode active materials for batteries may also be used. These positive electrode active materials may be used alone or in combination of two or more. Examples of lithium transition metal oxides may include, but are not limited to, lithium cobalt oxides (such as LiCoO2), lithium nickel oxides (such as LiNiO2), lithium manganese oxides (such as LiMnO2, LiMn2O4), lithium nickel cobalt oxides, lithium manganese cobalt oxides, lithium nickel manganese oxides, and lithium nickel cobalt manganese oxides (such as LiNi). 1 / 3 Co 1 / 3 Mn 1 / 3 O2 (also known as NCM) 333 LiNi 0.5 Co 0.2 Mn 0.3 O2 (also known as NCM) 523 LiNi 0.5 Co 0.25 Mn 0.25 O2 (also known as NCM) 211 LiNi 0.6 Co 0.2 Mn 0.2 O2 (also known as NCM) 622 LiNi 0.8 Co 0.1 Mn 0.1 O2 (also known as NCM) 811 ), lithium nickel cobalt aluminum oxide (such as LiNi) 0.8 Co 0.15 Al 0.05At least one of O2 and its modified compounds. Examples of lithium phosphates with an olivine structure may include, but are not limited to, lithium iron phosphate (such as LiFePO4 (also referred to as LFP)), lithium iron phosphate and carbon composites, lithium manganese phosphate (such as LiMnPO4), lithium manganese phosphate and carbon composites, lithium manganese iron phosphate, and lithium manganese iron phosphate and carbon composites. The modified compounds of the above materials may be for doping modification and / or surface coating modification of the materials.

[0224] During the charging and discharging process of a battery, Li undergoes insertion / extraction and consumption, resulting in varying molar Li content at different discharge states. In the examples of positive electrode active materials in this application, the molar Li content refers to the initial state of the material, i.e., the state before material addition. After charge-discharge cycles, the molar Li content changes when the positive electrode active material is applied to the battery system.

[0225] In the examples of positive electrode active materials in this application, the molar content of O is only a theoretical value. Oxygen release from the crystal lattice will cause changes in the molar content of oxygen, and the actual molar content of O will fluctuate.

[0226] In some embodiments of this application, when the battery is a sodium metal battery, the positive electrode active material may be a positive electrode active material known in the art for sodium-ion batteries.

[0227] As an example, the positive electrode active material may include at least one of the following materials: sodium transition metal oxides, polyanionic compounds, and Prussian blue sodium compounds, and their respective modified compounds. However, this application is not limited to these materials, and other conventional materials that can be used as positive electrode active materials for batteries may also be used. The modified compounds of the above materials may be for doping modification and / or surface coating modification of the materials.

[0228] In some embodiments of this application, the transition metal in the sodium transition metal oxide can be at least one selected from Ti, V, Mn, Co, Ni, Fe, Zn, V, Zr, Ce, Cr, and Cu. The chemical formula of the sodium transition metal oxide can satisfy Na y MO2, wherein M includes at least one of Ti, V, Mn, Co, Ni, Fe, Zn, V, Zr, Ce, Cr, and Cu, and 0 < y ≤ 1.

[0229] In some embodiments of this application, the polyanionic compound may be a compound containing sodium ions, transition metal ions, or a tetrahedral (YO4) structure. n- A class of compounds with anionic units. The transition metal may include at least one of Mn, Fe, Ni, Co, Cr, Cu, Ti, Zn, V, Zr, and Ce; Y may include at least one of P, S, and Si; n represents (YO4). n-The price state.

[0230] In some embodiments of this application, the polyanionic compound may also be a sodium ion, transition metal ion, or tetrahedral (YO4) compound. n- A class of compounds containing anionic units and halide anions. Transition metals may include at least one of Mn, Fe, Ni, Co, Cr, Cu, Ti, Zn, V, Zr, and Ce; Y may include at least one of P, S, and Si, where n represents (YO4). n- The valence state of halogens can include at least one of F, Cl, and Br.

[0231] In some embodiments of this application, the polyanionic compound may also be a tetrahedral compound containing sodium ions (YO4). n- Anionic unit, polyhedral unit (ZO) y ) m+ And a class of compounds with optional halide anions. M may include at least one of Mn, Fe, Ni, Co, Cr, Cu, Ti, Zn, V, Zr and Ce, Y may include at least one of P, S and Si, and n represents (YO4). n- The valence state, Z represents transition metal, m represents (ZO) y ) m+ The valence state of halogens can include at least one of F, Cl, and Br.

[0232] As an example, polyanionic compounds can satisfy the chemical formulas NaFePO4, Na3V2(PO4)3 (sodium vanadium phosphate, abbreviated as NVP), Na4Fe3(PO4)2(P2O7), NaM'PO4F (M' includes at least one of V, Fe, Mn and Ni), and Na3(VO y )2(PO4)2F 3-2y At least one of (0≤y≤1).

[0233] In some embodiments of this application, Prussian blue compounds may be compounds containing sodium ions, transition metal ions, and cyanide ions (CN). - A class of compounds. Transition metals may include at least one of Mn, Fe, Ni, Co, Cr, Cu, Ti, Zn, V, Zr, and Ce.

[0234] As an example, Prussian blue compounds can satisfy the chemical formula Na a Me b Me' c (CN)6, wherein Me and Me' each independently include at least one of Ni, Cu, Fe, Mn, Co, and Zn, 0 < a ≤ 2, 0 < b < 1, and 0 < c < 1.

[0235] During the charging and discharging process of a battery, sodium (Na) undergoes insertion / extraction and consumption, resulting in varying molar Na content at different discharge states. In the examples of positive electrode active materials in this application, the molar Na content refers to the initial state of the material, i.e., the state before material addition. After charge-discharge cycles, the molar Na content changes when the positive electrode active material is applied to the battery system.

[0236] In the examples of positive electrode active materials for sodium-ion batteries in this application, the molar content of O is only a theoretical value. Oxygen release from the crystal lattice will cause changes in the molar content of oxygen, and the actual molar content of O will fluctuate.

[0237] In some embodiments of this application, the positive electrode active material layer may optionally include a binder. As an example, the binder may include at least one selected from polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), PVDF-tetrafluoroethylene-propylene terpolymer, PVDF-hexafluoropropylene-tetrafluoroethylene terpolymer, tetrafluoroethylene-hexafluoropropylene copolymer, and fluorinated acrylate resin.

[0238] In some embodiments of this application, the positive electrode active material layer may optionally include a conductive agent. As an example, the conductive agent may include at least one selected from superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers.

[0239] In some embodiments of this application, the positive electrode sheet can be prepared by dispersing the above-mentioned components for preparing the positive electrode sheet, such as positive active material, conductive agent, binder, positive irreversible additive and any other components, in a solvent (e.g., N-methylpyrrolidone) to form a positive electrode slurry; coating the positive electrode slurry onto the positive electrode current collector, and after drying, cold pressing and other processes, the positive electrode sheet can be obtained.

[0240] In some embodiments of this application, the amount of hydrogen storage material added to the battery cell is 0.1 g / Ah-2 g / Ah. For example, it can be 0.1 g / Ah-1.9 g / Ah, 0.3 g / Ah-1.7 g / Ah, 0.5 g / Ah-1.5 g / Ah, 0.7 g / Ah-1.3 g / Ah, 1 g / Ah-1.1 g / Ah, etc. The amount of hydrogen storage material added is the mass of hydrogen storage material added per unit Ah of battery cell. Controlling the amount of hydrogen storage material added to the battery cell within the above range is sufficient to absorb the hydrogen gas produced by the battery cell without adding too much hydrogen storage material, which would affect the energy density of the battery cell. This can reduce the internal pressure of the battery cell, reduce the risk of thermal runaway, and extend the life of the battery cell. In other embodiments of this application, the amount of hydrogen storage material added is 0.1 g / Ah-0.75 g / Ah, for example, 0.2 g / Ah-0.5 g / Ah.

[0241] It is understandable that when the amount of hydrogen storage material added is 0.2g / Ah-0.5g / Ah, the battery life and energy density can be better balanced.

[0242] It is understood that "the amount of hydrogen storage material added to a single battery cell" is a well-known definition in the art and can be determined using methods known in the art, such as the following methods:

[0243] Disassemble the battery cell, disassemble the hydrogen storage component, scrape off the powder to obtain the hydrogen storage material (if the hydrogen storage material exists in the form of hydrogen storage material sheets, scrape off the hydrogen storage material sheets and calcine at 500℃ to decompose the binder), weigh the hydrogen storage material, divide it by the capacity of the battery cell to obtain the amount of hydrogen storage material added.

[0244] In some embodiments of this application, the operating voltage of the battery cell is 1.5V-4V. For example, it can be 1.5V-3.9V, 2V-3.5V, 2.5V-3V, etc. Since the operating voltage affects the amount of hydrogen produced by the battery cell, by controlling the operating voltage of the battery cell within the above range, the hydrogen storage material of this application is sufficient to absorb the hydrogen produced by the battery cell, which can reduce the generation of hydrogen in the battery cell and thus reduce the thermal runaway of the battery cell.

[0245] It is understood that the "operating voltage of a single battery cell" is a well-known definition in the art and can be measured using methods known in the art, such as the following methods;

[0246] Using a multimeter, connect the alligator clips to the positive and negative terminals of the battery cell respectively, and read the voltage.

[0247] In some embodiments of this application, the operating voltage of the battery cell is 1.5V-3V, and the amount of hydrogen storage material added is 0.02g / Ah-0.6g / Ah, for example, 0.02g / Ah-0.59g / Ah, 0.05g / Ah-0.55g / Ah, 0.1g / Ah-0.5g / Ah, 0.2g / Ah-0.4g / Ah, etc. Within this operating voltage range, the amount of hydrogen produced by the battery cell is relatively small, and the amount of hydrogen storage material added is 20%-30% of the total amount of additives. The hydrogen storage material is sufficient to absorb the hydrogen produced by the battery cell without causing waste due to excessive addition of hydrogen storage material.

[0248] In some embodiments of this application, the operating voltage of the battery cell is 3V-4V, and the amount of hydrogen storage material added is 0.07g / Ah-1.6g / Ah, for example, it can be 0.07g / Ah-1.5g / Ah, 0.1g / Ah-1.4g / Ah, 0.3g / Ah-1.2g / Ah, 0.5g / Ah-1g / Ah, etc. Within this operating voltage range, the battery cell produces relatively more hydrogen gas, and the amount of hydrogen storage material added is 70%-80% of the total amount of additives. The hydrogen storage material is sufficient to absorb the hydrogen gas produced by the battery cell without causing waste due to excessive addition of hydrogen storage material.

[0249] In some embodiments of this application, the battery cell includes a hydrogen storage material sheet, which comprises a substrate and a hydrogen storage material layer disposed on at least one side of the substrate, the hydrogen storage material layer comprising the hydrogen storage material. Therefore, by setting the hydrogen storage material in sheet form and disposing it within the battery cell, the dispersion caused by hydrogen storage material powder can be reduced, thus minimizing its impact on battery cell performance and hydrogen absorption efficiency, improving hydrogen absorption stability, further reducing the internal pressure of the battery, and extending the battery cell's lifespan.

[0250] Of course, hydrogen storage materials can also be in powder form. In this case, the hydrogen storage material can be packed into a plastic bag and then placed inside the battery cell; it can also be compressed into any shape and placed inside the battery cell.

[0251] In some embodiments of this application, based on the total mass of the hydrogen storage material layer, the mass percentage of the hydrogen storage material is ≥90%, for example, it can be 90%-99.5%, 91%-99%, 92%-98%, 93%-97%, 94%-96%, etc. By controlling the content of the hydrogen storage material in the hydrogen storage material layer within the above range, the hydrogen gas generated by the battery cell can be fully absorbed, further reducing the internal pressure of the battery and extending the life of the battery cell.

[0252] It is understood that "the mass percentage of hydrogen storage material based on the total mass of the hydrogen storage material layer" is a well-known definition in the art and can be determined using methods known in the art. For example, the following methods can be used for determination:

[0253] The hydrogen storage material layer is scraped into powder and weighed as m1. It is dissolved in acid, and the volume is adjusted. The content of metal elements is tested by elemental analysis-inductively coupled plasma atomic emission spectrometry and converted into the mass m2 of the hydrogen storage material. Based on the total mass of the hydrogen storage material layer, the mass ratio of the hydrogen storage material is m2 / m1×100%.

[0254] In some embodiments of this application, the hydrogen storage material layer further includes a second binder, which includes at least one of polytetrafluoroethylene, polyacrylic acid, carboxymethyl cellulose, or styrene-butadiene rubber. The introduction of the second binder can improve the bonding performance of the hydrogen storage material layer, reduce the shedding of the hydrogen storage material layer, improve the stability of the hydrogen storage material sheet, fully absorb the hydrogen generated by the battery cell, further reduce the internal pressure of the battery, and extend the life of the battery cell.

[0255] In some embodiments of this application, the substrate includes at least one of copper, nickel, aluminum, or stainless steel. The substrate can provide deposition space for the hydrogen storage material layer and can increase the strength of the hydrogen storage material sheet.

[0256] In some embodiments of this application, the thickness of the hydrogen storage material sheet is 0.1mm-4.5mm, for example, it can be 0.1mm-4.4mm, 0.3mm-4.2mm, 0.1mm-4mm, 0.5mm-3.5mm, 1mm-3mm, or 2mm-3mm. Controlling the thickness of the hydrogen storage material sheet within the above range allows the hydrogen storage material to fully contact and react with the hydrogen generated by the battery cell, absorb hydrogen, reduce the internal pressure of the battery, and extend the life of the battery cell.

[0257] Understandably, unless otherwise specified, the thickness of the hydrogen storage material sheet is determined using a micrometer.

[0258] In some embodiments of this application, the thickness of the hydrogen storage material layer is 0.05mm-1.25mm, for example, it can be 0.05mm-1.24mm, 0.1mm-1.2mm, 0.3mm-1mm, 0.5mm-0.8mm, etc. This thickness range is the thickness of the hydrogen storage material layer on one side of the substrate. By controlling the thickness of the hydrogen storage material layer within the above range, the hydrogen storage material can fully contact and react with the hydrogen generated by the battery cell, absorb hydrogen, reduce the internal pressure of the battery, and extend the life of the battery cell.

[0259] In some embodiments of this application, the thickness of the substrate is 10μm-150μm. For example, it can be 10μm-149μm, 20μm-145μm, 25μm-140μm, 30μm-135μm, 35μm-130μm, 40μm-120μm, 50μm-110μm, 60μm-100μm, 70μm-90μm, etc. Controlling the thickness of the substrate within the above range results in a higher content of hydrogen storage material in the hydrogen storage material sheet, allowing the hydrogen storage material to fully contact and react with the hydrogen generated by the battery cell, absorb hydrogen, reduce the internal pressure of the battery, and extend the life of the battery cell.

[0260] It is understood that, in the embodiments of this application, the thickness of the hydrogen storage material layer and the thickness of the substrate can be determined using the following methods:

[0261] The battery cell was disassembled, and the hydrogen storage material sheet was removed. The ion polished cross-sectional morphology (CP) image of the hydrogen storage material sheet was obtained using a scanning electron microscope. The thickness of the hydrogen storage material layer and the thickness of the substrate were measured at more than 5 locations selected from the image. The average value was taken to obtain the thickness of the hydrogen storage material layer and the thickness of the substrate.

[0262] It is understandable that the placement of the hydrogen storage material sheet in the battery cell is the same as the placement of the hydrogen storage material described below, and will not be repeated here.

[0263] Typically, a battery consists of a positive electrode, a negative electrode, an electrolyte, and a separator. During charging and discharging, active metal ions repeatedly insert and extract between the positive and negative electrodes. The electrolyte acts as a conductor of ions between the positive and negative electrodes. The separator, positioned between the positive and negative electrodes, primarily prevents short circuits while allowing ions to pass through.

[0264] The positive electrode, negative electrode, and electrolyte have been described in detail above and will not be repeated here.

[0265] This application does not impose any particular restrictions on the type of separator membrane; any known porous separator membrane with good chemical and mechanical stability can be selected.

[0266] In some embodiments of this application, the material of the separator may include at least one of glass fiber, nonwoven fabric, polyethylene, polypropylene, or polyvinylidene fluoride. The separator may be a single-layer film or a multi-layer composite film, without particular limitation. When the separator is a multi-layer composite film, the materials of each layer may be the same or different, without particular limitation.

[0267] The batteries of this application include battery cells, battery modules, and battery packs. The battery cells, battery modules, and battery packs of this application will be described below with appropriate reference to the accompanying drawings.

[0268] In some embodiments of this application, the positive electrode, negative electrode, and separator can be fabricated into an electrode assembly by a winding process or a stacking process.

[0269] In some embodiments of this application, the battery cell may include an outer packaging. This outer packaging can be used to encapsulate the aforementioned electrode assembly and electrolyte.

[0270] In some embodiments of this application, the outer packaging of the battery cell can be a hard shell, such as a hard plastic shell, an aluminum shell, or a steel shell. The outer packaging of the battery cell can also be a soft pack, such as a pouch. The material of the soft pack can be plastic; examples of plastics include polypropylene, polybutylene terephthalate, and polybutylene succinate.

[0271] A single battery cell can be a rechargeable battery. A rechargeable battery is a battery cell that can be recharged after it has been discharged, allowing the active materials to be activated and the cell to continue to be used.

[0272] The battery device mentioned in the embodiments of this application may include one or more battery cell assemblies for providing voltage and capacity. A battery cell assembly may include multiple battery cells, which may form a battery array, and the multiple battery cells may be connected in series, parallel, or in a mixed configuration via a busbar.

[0273] In some embodiments, a battery cell assembly is typically formed by arranging multiple battery cells, such as forming a battery array.

[0274] As an example, a battery cell assembly can be a battery module, which is formed by arranging and fixing multiple battery cells together to form an independent module. As another example, a battery module can be formed by bundling multiple battery cells together with cable ties.

[0275] In some embodiments, the battery device may be a battery pack, which includes a housing and one or more individual battery cell assemblies housed within the housing.

[0276] As an example, the battery cell assembly can be a battery module, which can be housed in a housing by fixing the battery module in the housing.

[0277] As an example, battery cell assemblies can also be housed in a housing by directly fixing multiple battery cells to the housing.

[0278] As an example, the enclosure may include a first enclosure and a second enclosure. The first enclosure and the second enclosure are fastened together to form a closed space inside the enclosure to house the individual battery cells. Here, "closed" refers to covering or closing, and can be either sealed or unsealed. The first enclosure may be a top cover or a bottom plate.

[0279] As an example, the enclosure may include a top cover, a frame, and a bottom plate. The top cover and bottom plate are connected to the frame, creating an enclosed space inside the enclosure to house the individual battery cells.

[0280] In some embodiments, the housing may be part of the vehicle's chassis structure. For example, a portion of the housing may be at least a part of the vehicle's floor, or a portion of the housing may be at least a part of the vehicle's crossbeams and longitudinal beams.

[0281] The technical solutions described in the embodiments of this application are applicable to battery devices and electrical devices using battery devices.

[0282] Electrical devices can include vehicles, mobile phones, portable devices, laptops, ships, spacecraft, electric toys, and power tools, etc. Vehicles can be gasoline-powered cars, natural gas-powered cars, or new energy vehicles; new energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. Spacecraft include airplanes, rockets, space shuttles, and spacecraft, etc. Electric toys include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Power tools include metal cutting power tools, grinding power tools, assembly power tools, and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, etc. This application does not impose any special limitations on the above-mentioned electrical devices.

[0283] For ease of explanation, the following embodiments will use a vehicle as an example of an electrical device.

[0284] Please refer to Figure 1, which is a schematic diagram of the structure of a vehicle provided in some embodiments of this application. A battery device 200 is installed inside the vehicle, and the battery device 200 can be located at the bottom, front, or rear of the vehicle. The battery device 200 can be used to power the vehicle; for example, the battery device 200 can serve as the vehicle's operating power source.

[0285] The vehicle may also include a controller 500 and a motor 400. The controller 500 controls the battery device 200 to supply power to the motor 400, which serves as a load, for example, for the power needs of the vehicle during starting, navigation and driving.

[0286] In some embodiments of this application, the battery device 200 can not only serve as the operating power source for the vehicle, but also as the driving power source for the vehicle, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle.

[0287] Please refer to Figure 2, which is an exploded view of a battery device 200 provided in some embodiments of this application. The battery device 200 includes a housing 600 for accommodating individual battery cells 100.

[0288] The housing 600 is a component that houses the individual battery cells 100. The housing 600 provides placement space for multiple battery cells 100 and can adopt various structures. In some embodiments, the housing 600 may include a tray and a cover, which overlap to define a placement space for accommodating the battery cells 100. The tray and cover can be of various shapes, such as cuboids, cylinders, etc. The tray can be a hollow structure open on one side, and the cover can also be a hollow structure open on one side, with the open side of the cover overlapping the open side of the tray, thus forming a housing 600 with placement space. Alternatively, the tray can be a hollow structure open on one side, and the cover can be a plate-like structure, overlapping the open side of the tray, thus forming a housing 600 with placement space. As an example, the battery cell 100 can be a cylindrical battery cell 100, a prismatic battery cell 100, or a battery cell 100 of other shapes (such as a pouch battery cell 100), and this application does not impose any particular limitations.

[0289] In the battery device 200, there can be one or more battery cells 100. If there are multiple battery cells 100, they can be connected in series, parallel, or in a mixed manner. A mixed connection means that multiple battery cells 100 are connected in both series and parallel. Alternatively, multiple battery cells 100 can be first connected in series, parallel, or in a mixed manner to form a battery module, and then multiple battery modules can be connected in series, parallel, or in a mixed manner to form a whole, which is then housed within the housing 600. Another option is that all battery cells 100 can be directly connected in series, parallel, or in a mixed manner, and then the whole consisting of all battery cells 100 is housed within the housing 600.

[0290] The battery cell 100 serves as the smallest energy unit of the battery device 200. The battery device 200 includes multiple battery cells 100. Each battery cell 100 includes a housing 10, an end cap 11, and an electrode assembly 20 disposed within the housing 10.

[0291] The battery cell 100 includes: a housing 10, an end cap 11, and an electrode assembly 20. The housing 10 is used to define an accommodating space with an installation opening. The housing 10 can be a pouch structure that wraps around the electrode assembly 20 for a pouch battery, or it can be constructed as a hard shell structure, with the electrode assembly 20 disposed therein.

[0292] For example, the housing 10 may include a base plate and a side plate. The side plate surrounds the periphery of the base plate and defines an accommodating space with a mounting opening. The electrode assembly 20 and other functional components may be disposed in the accommodating space. The end cap 11 covers the mounting opening of the housing 10 to isolate the internal environment of the battery cell 100 from the external environment. The shape of the end cap 11 is adapted to the shape of the housing 10. The end cap 11 may be supported by a material with a certain hardness and strength (such as aluminum alloy or carbon fiber plate). The end cap 11 can effectively protect the safety and reliability of the internal components of the housing 10 when squeezed or impacted.

[0293] In some embodiments, the end cap 11 may also be provided with a pressure relief mechanism for releasing internal pressure when the internal pressure or temperature of the battery cell 100 reaches a threshold. The end cap 11 can be made of various materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and this application embodiment does not impose any special limitations on this. In some embodiments, an insulating member may also be provided on the inner side of the end cap 11. The insulating member can be used to isolate the electrical connection components within the housing 10 from the end cap 11 to reduce the risk of short circuits. For example, the insulating member can be plastic, rubber, etc., and an insulating sheet can also be provided between the electrode assembly 20 and the housing 10 to achieve insulation protection.

[0294] The outer casing 10 is a component used to cooperate with the end cap 11 to form the internal environment of the battery cell 100, wherein the formed internal environment can accommodate the electrode assembly 20, electrolyte, and other components. The outer casing 10 and the end cap 11 can be independent components. A mounting opening can be provided on the outer casing 10, and the end cap 11 closes the opening at the mounting opening to form the internal environment of the battery cell 100. The outer casing 10 can be of various shapes and sizes, such as cuboid, cylindrical, hexagonal prism, etc. Specifically, the shape of the outer casing 10 can be determined according to the specific shape and size of the electrode assembly 20. The material of the outer casing 10 can be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and this application embodiment does not impose any special limitations on this.

[0295] Electrode assembly 20 is the component in the battery cell 100 where electrochemical reactions occur. The casing 10 may contain one or more electrode assemblies 20. The electrode assembly 20 is mainly formed by winding or stacking positive and negative electrode sheets, and typically a separator is provided between the positive and negative electrode sheets. The portions of the positive and negative electrode sheets containing active material constitute the main body of the electrode assembly 20, while the portions of the positive and negative electrode sheets without active material each constitute a tab 21. The positive and negative tabs may be located together at one end of the main body or separately at both ends of the main body. During the charging and discharging process of the battery device 200, the positive and negative active materials react with the electrolyte, and the tabs 21 connect to the electrode terminals 13 to form a current loop.

[0296] In related technologies, some battery systems (such as alkali metal batteries) produce a large amount of gas and produce gas rapidly during long-term cycling and storage. A considerable proportion of the gas is flammable and explosive hydrogen. The safety risk of the battery cell 100 is high. Not only is the gas emitted flammable, but the internal pressure is also high, which can easily lead to premature valve opening. The gas produced by the battery cell 100 needs to be discharged or treated in a timely manner.

[0297] It should be noted that common alkali metal batteries (including but not limited to lithium metal batteries, sodium metal batteries, potassium metal batteries, zinc metal batteries, and aluminum metal batteries) exhibit very significant differences in gas production patterns (including gas production amount, gas composition, and gas production rate) compared to secondary alkali ion batteries (such as lithium ion batteries, sodium ion batteries, and sodium-lithium ion batteries) during long-term charge and discharge processes.

[0298] Specifically, during the cycling and storage of battery cell 100, the amount of gas produced within battery cell 100 can accumulate rapidly in a short period of time, compressing the internal residual space of battery cell 100, and even causing the gas to be unable to be released, directly triggering the explosion-proof valve. At the same time, the gas produced by alkali metal batteries is often accompanied by reactive gases such as hydrogen and oxygen.

[0299] Based on the technical drawbacks of alkali metal batteries, such as large and rapid gas production, a high proportion of chemically active hydrogen, and the high risk of gas production and direct emission, the battery cell 100 of this application further incorporates a gas storage structure 30 within the casing 10 to rapidly absorb the produced gas within the casing 10. This maintains stable internal pressure within the battery cell 100, reducing the probability of premature valve opening and extending the service life of the battery cell 100. Furthermore, it improves venting and reduces the amount of hydrogen directly emitted, thereby enhancing safety.

[0300] The following description, with reference to Figures 1-26, describes a battery cell (alkali metal battery) 100, a battery device 200, and an electrical device 300 according to embodiments of this application.

[0301] As shown in Figures 3 and 4, this application provides a battery cell 100, including: an electrode assembly 20, an electrolyte, and a gas storage structure 30. The electrode assembly 20 is housed within a housing 10 and includes a positive electrode and a negative electrode. A gap is formed between the electrode assembly 20 and the housing 10. The electrolyte includes an electrolyte solution, which is housed within the housing 10. A portion of the electrolyte solution is immersed in the electrode assembly 20, and a portion of the electrolyte solution is housed within a part of the gap. The gas storage structure 30 is housed within the housing 10 and is at least partially located in the other part of the gap. At least a portion of the gas storage structure 30 is a hydrogen storage material.

[0302] The electrode assembly 20, electrolyte, and gas storage structure 30 are all disposed inside the outer casing 10. The electrolyte is filled inside the outer casing 10, and the gas storage structure 30 is used to absorb the gas (including but not limited to hydrogen) generated inside the outer casing 10.

[0303] Specifically, the internal space of the housing 10 is slightly larger than the size of the electrode assembly 20, so that after the electrode assembly 20 is assembled into the housing 10, a gap is formed between the housing 10 and the electrode assembly 20. The electrolyte is injected into the housing 10 and is suitable for wetting the electrode assembly 20 and filling at least part of the gap. The other part of the gap can be used to set the gas storage structure 30, so that the gas storage structure 30 can be set inside the housing 10 and can be separated from the electrolyte.

[0304] It should be noted that the outer casing 10 can be disposed inside the housing 600 of the battery device 200, and the electrolyte can be located below the outer casing 10 under the action of gravity. The upper part of the gap of the outer casing 10 can be used to accommodate the gas storage structure 30, and at least part of the gas storage structure 30 is a hydrogen storage material so that the gas storage structure 30 can absorb the hydrogen generated during the charging and discharging of the battery cell 100.

[0305] It is understood that other portions of the gap may include: a gap portion defined between the upper sidewall of the housing 10 and the upper side of the electrode assembly 20, and a gap portion defined between other sidewalls of the housing 10 on the periphery of the upper sidewall and other sidewalls of the electrode assembly 20 on the periphery of the upper sidewall and adjacent to a portion of the upper sidewall of the housing 10, the two gap portions collectively defining other portions of the gap.

[0306] For example, the housing 10 defines an accommodating space, the electrode assembly 20 is disposed within the accommodating space, the electrolyte is filled within the accommodating space and is suitable for wetting the electrode assembly 20, the gas storage structure 30 is disposed within the accommodating space, and the battery cell 100 is configured as an alkali metal battery. During the charging and discharging process, the electrolyte and the electrode assembly 20 react to generate a large amount of hydrogen gas, and the gas storage structure 30 can absorb the hydrogen gas to reduce gas accumulation inside the housing 10, thereby maintaining the pressure stability inside the housing 10, reducing the probability of the housing 10 bulging or premature valve opening, extending the service life of the battery cell 100, and reducing or even avoiding the emission of hydrogen gas to the outside, thereby improving the safety of the space where the battery cell 100 is located, and thus improving the safety of the battery cell 100 in use.

[0307] It should be noted that alkali metal batteries produce a large amount of gas and produce gas rapidly, which causes the pressure inside the casing 10 to rise rapidly in a short period of time. In this application, at least part of the gas storage structure 30 is located between the electrolyte surface and the top wall, which can improve the absorption efficiency of the gas storage structure 30 so that the absorption efficiency of the gas storage structure 30 can match the gas production rate, realize the immediate production and absorption of hydrogen inside the casing 10, and thus keep the pressure inside the casing 10 stable.

[0308] According to the embodiments of this application, the battery cell 100 has a gas storage structure 30 provided inside the outer casing 10, and the gas storage structure 30 can be located in another part of the gap. The gas storage structure 30 absorbs the hydrogen generated inside the outer casing 10, thereby reducing the probability of valve opening, extending the service life of the battery cell 100, reducing the amount of hydrogen emitted, improving safety, and improving absorption efficiency. This allows the hydrogen absorption rate to match the hydrogen generation rate, so that the pressure inside the outer casing 10 can be kept stable, reducing the probability of a sharp increase in pressure inside the outer casing 10 and maintaining internal pressure stability.

[0309] According to some embodiments of this application, the housing 10 includes a first wall 10a and a second wall 10b, the first wall 10a and the second wall 10b are disposed opposite to each other, the first wall 10a supports the electrode assembly 20, and at least a portion of the gap is formed between the second wall 10b and the electrode assembly 20, and at least a portion of the gas storage structure 30 is disposed between the electrode assembly 20 and the second wall 10b.

[0310] Specifically, the first wall 10a and the second wall 10b can be arranged opposite each other in the height direction, with the first wall 10a located below and adapted to carry and support the electrode assembly 20, while the second wall 10b is arranged opposite to the first wall 10a, and at least part of the gap is formed between the second wall 10b and the electrode assembly 20, and a gas storage structure 30 can be arranged in the gap between the second wall 10b and the electrode assembly 20.

[0311] Thus, the first wall 10a supports the electrode assembly 20 and is opposite to the second wall 10b, so that the electrolyte surface is located between the second wall 10b and the first wall 10a. The gas storage structure 30 is further disposed adjacent to the second wall 10b and is at least partially located between the electrolyte surface and the second wall 10b. That is, the gas storage structure 30 can be completely located between the electrolyte surface and the second wall 10b, or partially located between the electrolyte surface and the second wall 10b. The gas storage structure 30 located between the electrolyte surface and the second wall 10b has a larger contact area with hydrogen, which can improve the absorption efficiency of hydrogen generated inside the outer casing 10.

[0312] It is understood that the outer shell 10 can be a prism, such as a quadrangular prism or a hexagonal prism. The second wall 10b and the first wall 10a are relative concepts, meaning they are two opposing walls. These two walls can be defined by two opposing surfaces on the outer shell 10. For example, if the outer shell of the battery cell 100 is a quadrangular prism, the battery cell 100 includes a large surface area (the surface with the largest surface area), a battery end face (the surface from which the electrode terminals 13 are led), and a battery side face (the surface with a smaller surface area than the large surface area and adjacent to the battery end face and the large surface area). The two opposing large surface areas can be formed as the second wall 10b and the first wall 10a, respectively. The two opposing battery side faces can be formed as either the second wall 10b or the first wall 10a. The surfaces can be formed as a first wall 10a and a second wall 10b, respectively. That is, in the embodiment where the outer shell 10 of the battery cell 100 is a quadrangular prism, the battery cell 100 can be a square battery (i.e., the orthographic projection outline of the outer shell 10 is square), such as a conventional square battery (shortest length), a short-blade battery (length greater than a square battery but less than a long-blade battery), or a long-blade battery (longest length). The first wall 10a can be the large surface of the battery, the side surface of the battery, or the end surface of the battery. In the embodiment where the battery cell 100 is formed as a cylindrical battery, the first wall 10a can be the end surface or the side surface of the cylindrical battery. In the embodiment where the first wall 10a is the side surface of the cylindrical battery, the gas storage structure 20 can also be provided on the side surface, such as in the gap between the side surface of the outer shell 10 and the electrode assembly 20 to avoid the tabs 21, adapters, and other structures.

[0313] Similarly, it can be understood that the electrode assembly has a large electrode assembly surface 24, an electrode assembly end surface 23, and an electrode assembly side surface 22. The large electrode assembly surface 24 is opposite to the large battery surface, the electrode assembly side surface 22 is opposite to the battery side surface, and the electrode assembly end surface 23 is opposite to the battery end surface.

[0314] As shown in Figures 5, 6, 7, 8 and 9, according to some embodiments of this application, a first insulating member 40a is provided between the second wall 10b and the electrode assembly 20, a gas storage structure 30 is disposed between the first insulating member 40a and the second wall 10b, and / or, the gas storage structure 30 is disposed between the first insulating member 40a and the electrode assembly 20.

[0315] Specifically, the first insulating member 40a is used for insulation protection between the electrode assembly 20 and the second wall 10b. A gas storage structure 30 can be provided between the second wall 10b and the first insulating member 40a, or between the first insulating member 40a and the electrode assembly 20, or on the side of the first insulating member 40a facing the second wall 10b and the side of the first insulating member 40a facing the electrode assembly 20. This allows for more placement positions of the gas storage structure 30, enabling it to come into more full contact with the gas generated inside the outer casing 10, thereby improving the gas absorption effect and effectively maintaining the internal pressure of the outer casing 10. This reduces the probability of a sharp increase in internal pressure and improves the stability and reliability of the battery cell 100.

[0316] It is understood that an insulating element can be provided between the electrode assembly 20 and the housing 10. The housing 10 may include a housing body and an end cap 11 covering the housing body. A lower plastic can be provided between the electrode assembly 20 and the end cap 11, and an insulating sheet can be provided between the electrode assembly 20 and the housing 12. In some embodiments, the end cap 11 of the battery cell 100 defines a second wall 10b, in which case the first insulating element 40a can be a lower plastic. In other embodiments, the housing 12 of the battery cell 100 defines a second wall 10b, in which case the first insulating element 40a can be an insulating sheet.

[0317] According to some embodiments of this application, the second wall 10b faces the side surface of the first insulating member 40a, and / or the side surface of the first insulating member 40a facing the second wall 10b is connected to the gas storage structure 30, and / or the electrode assembly 20 faces the side surface of the first insulating member 40a, and / or the side surface of the first insulating member 40a facing the electrode assembly 20 is connected to the gas storage structure 30.

[0318] For example, in embodiments where the gas storage structure 20 is disposed on the side surface of the second wall 10b facing the first insulating member 40a, or where the gas storage structure 20 is disposed on the side surface of the first insulating member 40a facing the second wall 10b, the influence of electrolyte level fluctuations on the gas storage structure 20 can be reduced. In embodiments where the gas storage structure 20 is disposed on the side surface of the first insulating member 40a facing the electrode assembly 20, or on the side surface of the first insulating member 40a facing the second wall 10b, the gas storage structure 20 can be assembled into the housing 10 simultaneously with the first insulating member 40a, which can reduce assembly difficulty. In embodiments where the gas storage structure 20 is disposed on the side surface of the electrode assembly 20 facing the first insulating member 40a, the electrode assembly 20 can be assembled simultaneously with the gas storage structure 20, which can also reduce assembly difficulty.

[0319] In other words, the gas storage structure 30 can be disposed on the second wall 10b, or on the side surface of the first insulating member 40a facing the second wall 10b, or on the side surface of the first insulating member 40a facing the electrode assembly 20, or on the side surface of the electrode assembly 20 facing the first insulating member 40a.

[0320] This allows for a larger area within the battery cell 100 used to fix the gas storage structure 30, which not only improves the stability and reliability of the gas storage structure 30 but also reduces the difficulty of setting up the gas storage structure 30 and increases the processing efficiency of the battery cell 100.

[0321] As shown in Figures 6, 7, 8 and 9, according to some embodiments of this application, a tab space is formed between the first insulating member 40a and the electrode assembly 20, the tab space accommodates the tab, and at least a partial gas storage structure 30 is provided in the tab space.

[0322] Among them, the surface of the first insulating member 40a facing the electrode assembly 20 forms an electrode space for accommodating the electrode tab 21 between the electrode assembly 20 and the electrode assembly 20, and at least a partial gas storage structure 30 is provided in the electrode space.

[0323] In other words, there is a gap between the first insulating member 40a and the electrode assembly 20, and this gap can define the tab space, in which at least a partial gas storage structure 30 can be provided.

[0324] In this way, the gap space inside the outer shell 10 can be fully utilized, which can not only improve the gas absorption capacity of the gas storage structure 30, but also limit the electrode assembly 20 through the gas storage structure 30, thereby improving the fixation stability and reliability of the electrode assembly 20 inside the outer shell 10.

[0325] In some embodiments, the tab space includes: a tab region a accommodating the tab 21 and a void region b located around the tab region a, wherein at least a portion of the gas storage structure 30 is disposed in the tab region a and / or the void region b.

[0326] In other words, in some embodiments, a gas storage structure 30 can be provided in the tab region a, and in other embodiments, a gas storage structure 30 can be provided in the gap region b. In a preferred embodiment, a gas storage structure 30 can be provided in both the tab region a and the gap region b.

[0327] It should be noted that the electrode assembly 20 includes one or more bare cells. The bare cells can be a wound structure (wound core) formed by stacking and winding positive electrode sheets, separator film and negative electrode sheets, or a stacked structure (stacked core) formed by stacking positive electrode sheets, separator film and negative electrode sheets, cutting and stacking them. The wound core or stacked core has tabs 21 leading out. The tabs 21 are connected to the electrode terminals 13 on the end cover 11. A lower plastic (i.e., the first insulating member 40a) can be provided between the electrode terminals 13 and the end cover 11. There is a gap between the lower plastic and the electrode assembly 20, and the tabs 21 are located in the gap. The corresponding gas storage structure 30 can also be provided in the gap and avoid the tabs 21.

[0328] For example, the gap between the lower plastic and the electrode assembly 20 can be divided into two parts. The first part is the part without the tab 21 (see Figures 6 and 8, i.e., gap region b), and the second part is the part with the tab 21 (see Figures 7 and 9, tab region a). The gap region b can be filled with the gas storage structure 30 in whole or in part, while the tab region a can be filled with the gas storage structure 30 while avoiding the tab 21.

[0329] In this way, the gas storage structure 30 is positioned more reasonably. On the one hand, it can be located between the electrolyte surface and the second wall 10b, so that the gas storage structure 30 can fully contact the gas generated inside the outer shell 10, thereby improving the absorption efficiency and absorption effect. On the other hand, it can make full use of the gap between the first insulating member 40a and the electrode assembly 20, thereby improving the space utilization rate. The overall volume of the gas storage structure 30 is larger, and the hydrogen absorption capacity is stronger, so that it can absorb more hydrogen and thus better maintain the stability of the internal pressure of the outer shell 10.

[0330] It should be noted that, as shown in Figures 6 and 8, the gas storage structure 30 is set in the gap region b, which can play an auxiliary supporting role for the electrode assembly 20, making the electrode assembly 20 more stable in the shell 10 and reducing the probability of movement. It can also improve the safety and reliability of the battery cell 100, as shown in Figures 7 and 9. The tab region a has a tab 21, and the gas storage structure 30 is set in the tab region a. While supporting and limiting the electrode assembly 20, it can also shape and limit the tab 21, preventing the tab 21 from being inserted into the shell, and further improving the reliability and stability of the electrode assembly 20.

[0331] Furthermore, within the tab region a, a gas storage structure 30 is provided in the gap between adjacent tabs 21, and / or in the gap between the tab 21 and the outer shell 20.

[0332] Specifically, the bare cell has a wound or stacked structure, and the tabs 21 of multiple positive electrode plates are connected to the positive terminal, and the tabs 21 of multiple negative electrode plates are connected to the negative terminal. There are gaps between the tabs 21 of multiple positive electrode plates and between the tabs 21 of multiple negative electrode plates. At least part of the gas storage structure 30 can be filled in these gaps. At the same time, there is also a gap between the tabs 21 and the outer casing 20, which can also be filled with the gas storage structure 30.

[0333] It is understandable that filling the gap between adjacent tabs 21 with a gas storage structure 30 can improve the air intake effect, support the tabs 21, reduce the deformation of the tabs 21, and improve the reliability and stability of the connection between the tabs 21 and the electrode terminal 13. Filling the gap between the tabs 21 and the outer shell 20 with a gas storage structure 30 can limit the tabs 21, reduce the movement of the tabs 21, and improve the reliability of the battery cell 100.

[0334] As shown in FIG5, according to some embodiments of the present application, the first insulating member 40a has a receiving cavity 41, which is open on the side facing the second wall 10b and / or on the side facing the electrode assembly 20 to receive the gas storage structure 30, and the receiving cavity 41 is in communication with the gap.

[0335] In other words, the first insulating member 40a can be used to achieve insulation between the end cap 11 and the electrode assembly 20. The first insulating member 40a can generally be formed into a plate structure, and one or more accommodating cavities 41 can be opened on the plate, and the gas storage structure 30 is disposed in the accommodating cavity 41.

[0336] Therefore, under the premise of absorbing the gas generated inside the outer shell 10, the gas storage structure 30 can be set inside the accommodating cavity 41 of the first insulating member 40a. Setting the gas storage structure 30 has less impact on the internal space of the outer shell 10 and can also take into account the energy density.

[0337] The lower plastic is located between the second wall 10b and the electrode assembly 20, and a gas storage structure 30 can be provided between the outer shell 10 and the lower plastic, and a gas storage structure 30 can also be provided between the lower plastic and the electrode assembly 20.

[0338] In other words, in some embodiments, the gas storage structure 30 is disposed between the lower plastic and the outer shell 10, in other embodiments, the gas storage structure 30 is disposed between the lower plastic and the electrode assembly 20, and in preferred embodiments, the gas storage structure 30 can be disposed between the lower plastic and the outer shell 10 and between the lower plastic and the electrode assembly 20.

[0339] Therefore, in the embodiment where the end cap 11 defines the second wall 10b, the gas storage structure 30 is disposed between the lower plastic and the outer shell 10, and / or between the lower plastic and the electrode assembly 20. The placement of the gas storage structure 30 is more reasonable, allowing more gas storage structures 30 to be located between the electrolyte surface and the second wall 10b, thereby improving the hydrogen absorption efficiency.

[0340] As shown in FIG5, according to some embodiments of the present application, the first insulating member 40a includes a limiting portion 42, which is located between the second wall 10b and the electrode assembly 20. The limiting portion 42 protrudes toward the electrode assembly 20 and pushes against the electrode assembly 20, and a receiving cavity is formed in the limiting portion 42.

[0341] That is, the lower plastic has a limiting part 42 for limiting the electrode assembly 20, and the limiting part 42 has a receiving cavity 41 on the side away from the electrode assembly 20, or the limiting part 42 has a receiving cavity 41 on the side facing the electrode assembly 20, and the gas storage structure 30 is disposed in the receiving cavity 41.

[0342] Specifically, the electrode assembly 20 has a positive electrode tab and a negative electrode tab, and the limiting part 42 on the lower plastic can include two limiting parts 42 located at both ends of the lower plastic. The multiple limiting parts 42 are used to press against and limit the electrode assembly 20, which can improve the fixing stability and reliability of the electrode assembly 20.

[0343] Furthermore, by setting the gas storage structure 30 within the accommodating cavity 41, on the one hand, there is no need to make major structural changes to the end cap 11 while setting the gas storage structure 30, and the thickness of the end cap 11 can remain unchanged to take into account the energy density of the battery cell 100. On the other hand, the gas storage structure 30 can be fixed by using the accommodating cavity 41 opened on the limiting part 42. The accommodating cavity 41 can limit the gas storage structure 30 to reduce the probability of the gas storage structure 30 shifting. The gas storage structure 30 is less affected by the fluctuation of the electrolyte level and can always be located above the electrolyte level, so that the absorption effect of the gas storage structure 30 is less affected by the fluctuation of the electrolyte and the effect of maintaining the internal pressure of the outer casing 10 is better.

[0344] Referring to Figure 5, according to some embodiments of this application, the second wall 10b is provided with an explosion-proof element 14, which is configured to break when the pressure inside the housing 10 reaches a set condition to release the gas inside the housing 10. The first insulating element 40a has a connecting portion for connecting the internal space of the housing 10 with the explosion-proof element 14, and at least a portion of the gas storage structure 30 is disposed in the connecting portion.

[0345] Among them, the explosion-proof component 14 is constructed as an explosion-proof valve, which can be assembled to the second wall 10b or integrally formed with the second wall 10b. A connecting part is formed on the first insulating component 40a. The connecting part is used to connect the internal space of the outer shell 10 with the outside. Therefore, the gas inside the outer shell 10 is suitable to enter the connecting part. The connecting part is provided with a corresponding gas storage structure 20, which can further increase the number of gas storage structures 20 to improve the gas intake effect and improve the space utilization rate.

[0346] It is understood that in some embodiments, the connecting portion is constructed as a connecting groove c formed on the first insulating member 40a. The connecting groove c extends along the side surface of the first insulating member 40a facing the electrode assembly 20 to the side surface of the first insulating member 40a away from the electrode assembly 20. This allows the gas inside the housing 10 to be discharged through the connecting groove c and the opened explosion-proof member 14 when the internal pressure of the housing 10 exceeds the pressure threshold that the explosion-proof member 14 can withstand, thereby realizing the timely release of the battery cell 100 and improving the reliability of the battery device 200.

[0347] Furthermore, a gas storage structure 30 can be further provided in the communicating groove c defined by the first insulating member 40a. The gas storage structure 30 can be provided in the first insulating member 40a to achieve gas absorption inside the outer casing 10. Under the premise of maintaining stable internal pressure, the internal space of the outer casing 10 can be fully utilized to improve the gas absorption effect while taking into account the energy density of the battery cell 100.

[0348] As shown in Figures 10 and 12, according to some embodiments of this application, a second insulating member 40b is provided between the third wall 10c and the electrode assembly 20, a gas storage structure 30 is disposed between the second insulating member 40b and the third wall 10c, and / or the gas storage structure 30 is disposed between the second insulating member 40b and the electrode assembly 20.

[0349] Specifically, the second insulating member 40b is used for insulation protection between the electrode assembly 20 and the third wall 10c. A gas storage structure 30 can be provided between the third wall 10c and the second insulating member 40b, or between the second insulating member 40b and the electrode assembly 20, or on the side of the second insulating member 40b facing the third wall 10c and the side of the second insulating member 40b facing the electrode assembly 20, so that there are more possible positions for the gas storage structure 30. The gas storage structure 30 can come into more full contact with the gas generated inside the outer casing 10, so as to improve the gas absorption effect.

[0350] It is understood that an insulating element can be provided between the electrode assembly 20 and the housing 10. The housing 10 may include a housing body and an end cap 11 covering the housing body. A lower plastic can be provided between the electrode assembly 20 and the end cap 11, and an insulating sheet can be provided between the electrode assembly 20 and the housing 12. In some embodiments, the end cap 11 of the battery cell 100 defines a third wall 10c, in which case the second insulating element 40b can be a lower plastic. In other embodiments, the housing 12 of the battery cell 100 defines a third wall 10c, in which case the second insulating element 40b can be an insulating sheet.

[0351] According to some embodiments of this application, the third wall 10c faces the side surface of the second insulating member 40b, and / or the side surface of the second insulating member 40b facing the third wall 10c is connected to the gas storage structure 30, and / or the electrode assembly 20 faces the side surface of the second insulating member 40b, and / or the side surface of the second insulating member 40b facing the electrode assembly 20 is connected to the gas storage structure 30.

[0352] For example, in embodiments where the gas storage structure 20 is disposed on the side surface of the third wall 10c facing the second insulating member 40b, or where the gas storage structure 20 is disposed on the side surface of the second insulating member 40b facing the third wall 10c, the influence of electrolyte level fluctuations on the gas storage structure 20 can be reduced. In embodiments where the gas storage structure 20 is disposed on the side surface of the second insulating member 40b facing the electrode assembly 20, and on the side surface of the second insulating member 40b facing the third wall 10c, the gas storage structure 20 can be assembled into the housing 10 simultaneously with the second insulating member 40b, which can reduce assembly difficulty. In embodiments where the gas storage structure 20 is disposed on the side surface of the electrode assembly 20 facing the second insulating member 40b, the electrode assembly 20 can be assembled simultaneously with the gas storage structure 20, which can also reduce assembly difficulty.

[0353] In other words, the gas storage structure 30 can be disposed on the third wall 10c, or on the side surface of the second insulating member 40b facing the third wall 10c, or on the side surface of the second insulating member 40b facing the electrode assembly 20, or on the side surface of the electrode assembly 20 facing the second insulating member 40b.

[0354] This allows for a larger area within the battery cell 100 used to fix the gas storage structure 30, which not only improves the stability and reliability of the gas storage structure 30 but also reduces the difficulty of setting up the gas storage structure 30 and increases the processing efficiency of the battery cell 100.

[0355] According to some embodiments of this application, the second insulating member 40b has a receiving cavity 41, which is open on the side facing the third wall 10c and / or on the side facing the electrode assembly 20 to receive the gas storage structure 30, and the receiving cavity 41 is in communication with the gap.

[0356] In other words, the second insulating member 40b can be used to achieve insulation between the end cap 11 and the electrode assembly 20. The second insulating member 40b can generally be formed into a plate structure, and one or more accommodating cavities 41 can be opened on the plate, and the gas storage structure 30 is disposed in the accommodating cavity 41.

[0357] Therefore, under the premise of absorbing the gas generated inside the outer shell 10, the gas storage structure 30 can be set inside the accommodating cavity 41 of the second insulating member 40b. Setting the gas storage structure 30 has less impact on the internal space of the outer shell 10 and can also take into account the energy density.

[0358] The lower plastic is located between the third wall 10c and the electrode assembly 20, and a gas storage structure 30 can be provided between the outer shell 10 and the lower plastic, and a gas storage structure 30 can also be provided between the lower plastic and the electrode assembly 20.

[0359] In other words, in some embodiments, the gas storage structure 30 is disposed between the lower plastic and the outer shell 10, in other embodiments, the gas storage structure 30 is disposed between the lower plastic and the electrode assembly 20, and in preferred embodiments, the gas storage structure 30 can be disposed between the lower plastic and the outer shell 10 and between the lower plastic and the electrode assembly 20.

[0360] Therefore, in the embodiment where the end cap 11 defines the third wall 10c, the gas storage structure 30 is disposed between the lower plastic and the outer shell 10, and / or between the lower plastic and the electrode assembly 20. The placement of the gas storage structure 30 is more reasonable, allowing more gas storage structures 30 to be located between the electrolyte surface and the second wall 10b, thereby improving the hydrogen absorption efficiency.

[0361] According to some embodiments of this application, the second insulating member 40b includes a limiting portion 42, which is located between the third wall 10c and the electrode assembly 20. The limiting portion 42 protrudes toward the electrode assembly 20 and pushes against the electrode assembly 20; a receiving cavity 41 is formed in the limiting portion 42.

[0362] That is, the lower plastic has a limiting part 42 for limiting the electrode assembly 20, and the limiting part 42 has a receiving cavity 41 on the side away from the electrode assembly 20, or the limiting part 42 has a receiving cavity 41 on the side facing the electrode assembly 20, and the gas storage structure 30 is disposed in the receiving cavity 41.

[0363] Specifically, the electrode assembly 20 has a positive electrode tab and a negative electrode tab, and the limiting part 42 on the lower plastic can include two limiting parts 42 located at both ends of the lower plastic. The multiple limiting parts 42 are used to press against and limit the electrode assembly 20, which can improve the fixing stability and reliability of the electrode assembly 20.

[0364] Furthermore, by setting the gas storage structure 30 within the accommodating cavity 41, on the one hand, there is no need to make major structural changes to the end cap 11 while setting the gas storage structure 30, and the thickness of the end cap 11 can remain unchanged to take into account the energy density of the battery cell 100. On the other hand, the gas storage structure 30 can be fixed by using the accommodating cavity 41 opened on the limiting part 42. The accommodating cavity 41 can limit the gas storage structure 30 to reduce the probability of the gas storage structure 30 shifting. The gas storage structure 30 is less affected by the fluctuation of the electrolyte level and can always be located above the electrolyte level, so that the absorption effect of the gas storage structure 30 is less affected by the fluctuation of the electrolyte and the effect of maintaining the internal pressure of the outer casing 10 is better.

[0365] According to some embodiments of this application, a tab space is formed between the second insulating member 40b and the electrode assembly 20, the tab space accommodates the tab 21, and at least a partial gas storage structure 30 is provided in the tab space.

[0366] Among them, the second insulating member 40b forms an electrode space for accommodating the electrode tab 21 between its side surface facing the electrode assembly 20 and the electrode assembly 20, and at least a partial gas storage structure 30 is provided in the electrode space.

[0367] In other words, there is a gap between the second insulating member 40b and the electrode assembly 20, and this gap can define the tab space, in which at least a partial gas storage structure 30 can be provided.

[0368] In this way, the gap space inside the outer shell 10 can be fully utilized, which can not only improve the gas absorption capacity of the gas storage structure 30, but also limit the electrode assembly 20 through the gas storage structure 30, thereby improving the fixation stability and reliability of the electrode assembly 20 inside the outer shell 10.

[0369] According to some embodiments of this application, the electrode space includes: a folded electrode region a that accommodates the electrode 21 and a void region b located around the folded electrode region a, with at least a portion of the gas storage structure 30 disposed in the void region b.

[0370] It should be noted that the tab 21 is connected to the electrode terminal 13 on the end cover 11. A lower plastic (i.e., the second insulating part 40b) can be provided between the electrode terminal 13 and the end cover 11. There is a gap between the lower plastic and the electrode assembly 20, and the tab 21 is located in the gap. The corresponding gas storage structure 30 can also be provided in the gap, while avoiding the tab 21.

[0371] For example, the gap between the lower plastic and the electrode assembly 20 can be divided into two parts: the first part is the part without the tab 21, and the second part is the part with the tab 21. The gap region b can be filled with the gas storage structure 30 in whole or in part, while the tab region a is located below the electrolyte surface, so the tab region a is not provided with the gas storage structure 30.

[0372] In this way, the gas storage structure 30 is positioned more reasonably. On the one hand, it can be located between the electrolyte surface and the third wall 10c, so that the gas storage structure 30 can fully contact the gas generated inside the outer shell 10, thereby improving the absorption efficiency and absorption effect. On the other hand, it can make full use of the gap between the second insulating member 40b and the electrode assembly 20, thereby improving the space utilization rate. The overall volume of the gas storage structure 30 is larger, and its hydrogen absorption capacity is stronger, allowing it to absorb more hydrogen and thus better maintain the stability of the internal pressure of the outer shell 10.

[0373] It should be noted that the gas storage structure 30 located between the third wall 10c and the electrode assembly 20 is disposed adjacent to the second wall 10b, and the maximum distance between it and the second wall 10b is less than or equal to 5mm.

[0374] Specifically, a gap is formed between the electrode assembly 20 and the housing 10, and a portion of the gap is used to contain the electrolyte. The other portion of the gap includes: a first other portion defined by the second wall 10b and the area opposite to the electrode assembly 20, and a second other portion defined by the electrode assembly 20 and the third wall 10c. The second other portion is the portion defined by the third wall 10c and the electrode assembly 20, which is located side-up in the placement direction and above the electrolyte based on the placement direction of the battery cell 100.

[0375] Therefore, the gas storage structure 30 located between the third wall 10c and the electrode assembly 20 is positioned adjacent to the second wall 10b, i.e., above it, and the maximum distance between it and the second wall 10b is less than or equal to 5mm, so as to ensure that the gas storage structure 30 located between the third wall 10c and the electrode assembly 20 can be positioned above the electrolyte surface, thereby improving the gas intake effect and gas intake efficiency.

[0376] For example, as shown in Figures 10 and 12, the gas storage structure 30 disposed between the third wall 10c and the electrode assembly 20 is adjacent to the second wall 10b, and the maximum distance L1 between the structure and the second wall 10b is less than or equal to 5 mm.

[0377] As shown in Figure 10, in the second embodiment, the large surface of the battery defines the second wall 10b, the end face of the battery defines the third wall 10c, and the second insulating member 40b is a lower plastic. The maximum distance between the gas storage structure 30 disposed on the lower plastic near the second wall 10b and the second wall 10b can be 1mm, 2mm, 3mm, 4mm, 5mm, etc. With this arrangement, when the electrolyte is not fluctuating, the gas storage structure 30 can be entirely or at least partially located above the electrolyte surface. When the electrolyte surface fluctuates, the gas storage structure 30 is less affected by the fluctuation, and a larger portion of the gas storage structure 30 can be located above the electrolyte surface to ensure a stable and reliable hydrogen absorption effect.

[0378] As shown in Figure 12, in the third embodiment, a second wall 10b is defined on the side of the battery, a third wall 10c is defined on the end face of the battery, and the second insulating member 40b is a lower plastic. The maximum distance between the gas storage structure 30 disposed on the lower plastic near the second wall 10b and the second wall 10b can be 1mm, 2mm, 3mm, 4mm, 5mm, etc. With this configuration, when the electrolyte is not fluctuating, the gas storage structure 30 can be entirely or at least partially located above the electrolyte surface. When the electrolyte surface fluctuates, the gas storage structure 30 is less affected by the fluctuation, and a larger portion of the gas storage structure 30 can be located above the electrolyte surface to ensure a stable and reliable hydrogen absorption effect.

[0379] As shown in Figure 2, this application proposes a battery device 200, including: the battery cell 100 in the above embodiment.

[0380] According to the battery device 200 of the present application embodiment, a battery cell 100 is provided inside the housing 600, and a gas storage structure 30 is integrated inside the battery cell 100. The internal pressure of the battery cell 100 is more stable, and less hydrogen is emitted into the housing 600 during operation. This not only improves the service life of the battery device 200, but also improves the safety and reliability of the battery device 200 and reduces safety hazards.

[0381] As shown in Figure 3, this application provides an electrical device 300, including the battery device 200 in the above embodiment.

[0382] Referring to Figure 2, the battery device 200 has a housing 600, and the battery cells 100 can be arranged in an array within the housing 600. In embodiments where the battery cells 100 are constructed as square batteries in the vertical direction of the housing 600, the battery cells 100 can be arranged with the end cap 11 facing upward within the housing 600, and the gas storage structure 30 can be disposed between the end cap 11 and the electrode assembly 20, or disposed within the end cap 11. Alternatively, the battery cells 100 can be arranged with their battery sides facing upward within the housing 600, and the gas storage structure 30 can be disposed between the first side plate and the electrode assembly 20, or between the first side plate defining the second wall 10b near the end cap 11 and the electrode assembly 20. Alternatively, the battery cells 100 can be arranged with their battery sides facing upward within the housing 600, and the gas storage structure 30 can be disposed between the second side plate and the electrode assembly 20, or between the second side plate defining the second wall 10b near the end cap 11 and the electrode assembly 20.

[0383] Of course, the battery cell 100 can also be constructed as a cylindrical battery, with the axis of the cylindrical battery parallel to the vertical direction, and a gas storage structure 30 can be set inside the end cap 11 located on the top of the cylindrical battery.

[0384] The battery cell 100 of the present application embodiment will be described in detail below with reference to Figures 5-23.

[0385] First embodiment:

[0386] As shown in Figures 5, 6, 7, 8 and 9, in the first embodiment, the battery cell 100 is constructed as a square battery, the second wall 10b leads out the electrode terminal 13 and is defined by the end cap 11, the third wall 10c is the side of the battery and the large surface of the battery, the first insulating member 40a is the lower plastic and the second insulating member 40b is the insulating sheet.

[0387] The lower plastic has a accommodating cavity 41 in the limiting part 42 at both ends, and an exhaust channel facing the explosion-proof part 14 on the lower plastic. An electrode tab space is formed between the lower plastic and the electrode assembly 20. The electrode tab space includes a gap area b and a folded electrode tab area a. A gas storage structure 30 is set in the accommodating cavity 41, the exhaust channel, the gap area b and the folded electrode tab area a. A gas storage structure 30 is also set between the insulating sheet and the third wall 10c and between the insulating sheet and the electrode assembly 20.

[0388] Second embodiment:

[0389] As shown in Figures 10 and 11, in the second embodiment, the battery cell 100 is constructed as a square battery, the third wall 10c leads out the electrode terminal 13, and the second wall 10b is defined by the large surface of the battery. The third wall 10c is defined by the end cap 11. The first insulating member 40a is an insulating sheet, and the second insulating member 40b is a lower plastic.

[0390] The lower plastic has a accommodating cavity 41 in the limiting part 42 at both ends, and an electrode tab space is formed between the lower plastic and the electrode assembly 20. The electrode tab space includes a gap region b and a folded electrode tab region a. The gas storage structure 30 is provided in the accommodating cavity 41 and the gap region b adjacent to the second wall 10b. Gas storage structures 30 are also provided between the insulating sheet and the second wall 10b and between the insulating sheet and the electrode assembly 20.

[0391] As shown in Figures 12 and 13, in the third embodiment, the battery cell 100 is constructed as a square battery, the third wall 10c leads out the electrode terminal 13, and the second wall 10b is defined by the side of the battery. The third wall 10c is defined by the end cap 11. The first insulating member 40a is an insulating sheet, and the second insulating member 40b is a lower plastic.

[0392] The lower plastic has a accommodating cavity 41 in the limiting part 42 at both ends, and an electrode tab space is formed between the lower plastic and the electrode assembly 20. The electrode tab space includes a gap region b and a folded electrode tab region a. The gas storage structure 30 is provided in the accommodating cavity 41 and the gap region b adjacent to the second wall 10b. Gas storage structures 30 are also provided between the insulating sheet and the second wall 10b and between the insulating sheet and the electrode assembly 20.

[0393] As shown in Figures 14 and 15, in the fourth embodiment, the battery cell 100 is constructed as a square battery, the first wall 10a leads out the electrode terminal 13, the first insulating member 40a and the second insulating member 40b are both constructed as insulating sheets, and gas storage structures 30 are provided between the insulating sheet and the second wall 10b, between the insulating sheet and the third wall 10c, and between the insulating sheet and the electrode assembly 20, and the gas storage structure 30 between the third wall 10c and the electrode assembly 20 is located adjacent to the second wall 10b.

[0394] As shown in Figures 16 and 17, in the fifth embodiment, the battery cell 100 is constructed as a short-blade battery or a long-blade battery, the third wall 10c leads out the electrode terminal 13, the large surface of the battery defines the second wall 10b, the second insulating member 40b is constructed as a lower plastic, and the first insulating member 40a is constructed as an insulating sheet.

[0395] The lower plastic has limiting portions 42 at both ends of its length. Each limiting portion 42 has a receiving cavity 41. The receiving cavity 41 has a baffle 411 extending along the width direction of the lower plastic. The baffle 411 divides the lower plastic into multiple cavities. One or more cavities adjacent to the second wall 10b are provided with a gas storage structure 30. Gas storage structures 30 are also provided between the second wall 10b and the insulating sheet, and between the insulating sheet and the electrode assembly 20.

[0396] As shown in Figures 18 and 19, in the fifth embodiment, the battery cell 100 is constructed as a short-blade battery or a long-blade battery, the third wall 10c leads out the electrode terminal 13, the side of the battery defines the second wall 10b, the second insulating member 40b is constructed as lower plastic, and the first insulating member 40a is constructed as an insulating sheet.

[0397] The lower plastic has limiting portions 42 at both ends of its length. Each limiting portion 42 has a receiving cavity 41. The receiving cavity 41 has a baffle 411 extending along the length of the lower plastic. The baffle 411 divides the lower plastic into multiple cavities. A gas storage structure 30 is provided in one or more cavities adjacent to the second wall 10b. Gas storage structures 30 are also provided between the second wall 10b and the insulating sheet, and between the insulating sheet and the electrode assembly 20.

[0398] As shown in Figure 20, in the sixth embodiment, the battery cell 100 is constructed as a short-blade battery or a long-blade battery, the third wall 10c leads out the electrode terminal 13, the side of the battery or the large surface of the battery defines the second wall 10b, and the first insulating member 40a is constructed as an insulating sheet.

[0399] Among them, a gas storage structure 30 is also provided between the second wall 10b and the insulating sheet, and between the insulating sheet and the electrode assembly 20.

[0400] As shown in Figures 21 and 22, in the seventh embodiment, the battery cell 100 is constructed as a cylindrical battery, the second wall 10b leads out the electrode terminal 13, and the end cap 11 defines the second wall 10b. The first insulating member 40a is constructed as a lower plastic.

[0401] The end cap 11 has multiple limiting parts 42, and each of the multiple limiting parts 42 is equipped with a gas storage structure 30.

[0402] As shown in Figure 23, according to some embodiments of this application, the gas storage structure 30 includes: a covering shell 31 and a gas storage material 32 filled in the covering shell 31. At least a portion of the gas storage material 32 is a hydrogen storage metal. The gas storage material 32 is configured as granules or powder. The covering shell 31 has vent holes formed on it, and the vent hole diameter is smaller than the particle size of the gas storage material 32. The covering shell 31 is connected to the third wall 10c, the second insulating member 40b, or the electrode assembly 20.

[0403] The following describes embodiments of this application. The embodiments described below are exemplary and are only used to explain this application, and should not be construed as limiting this application. Where specific techniques or conditions are not specified in the embodiments, they are performed according to the techniques or conditions described in the literature in this field or according to the product instructions. Reagents or instruments used, unless otherwise specified, are all conventional products that can be obtained commercially.

[0404] Example 1

[0405] Preparation of hydrogen storage materials:

[0406] Rare earth metals La, Ni, Mn, Y, and Bi were selected.

[0407] According to the molar ratio, the weighed bulk metal is placed in a zirconia crucible according to the designed process. The vacuum induction melting furnace is evacuated to a vacuum level of 1×10⁻⁶ before heating. -3 The pressure was increased to above 100 MPa; then, 0.05 MPa of inert argon gas was introduced into the furnace as a protective gas; the heating temperature was adjusted to 1500℃; the liquid alloy was held at the molten state for 5 minutes; then, the uniformly mixed liquid metal was poured into a copper mold, cooled to room temperature in the furnace, and removed to obtain the master alloy ingot LaNi. 3.5 Mn 0.2 YBi 0.3 The hydrogen storage material has a volume average particle size (Dv50) of 10 μm and a BET specific surface area of ​​1 g / cm³. 2 Its saturated aqueous solution has a pH of 10 at 25℃ and a tap density of 5 g / cm³. 3 The compacted density is 6 g / cm³. 3 .

[0408] The above-mentioned hydrogen storage material and binder polytetrafluoroethylene (PTFE) were mixed at a mass ratio of 95:5, deionized water was added and stirred to disperse and form a slurry. The slurry was then coated onto a 20μm thick copper foil. After both sides were coated, the foil was dried, cold-pressed, slit, and sheeted to obtain a hydrogen storage material sheet with a size of 100mm×20mm (total thickness of 1.02mm, and the thickness of the hydrogen storage material layer on one side is 0.5mm).

[0409] 1. Preparation of positive electrode sheet

[0410] Sodium-ion battery positive electrode active material (sodium iron pyrophosphate, residual alkali content of 0.5%), conductive agent (conductive carbon black), and binder (polyvinylidene fluoride) are mixed in a ratio of 90:5:5. Then, solvent (N-methylpyrrolidone, NMP) is added and stirred to disperse the mixture, thus preparing a positive electrode slurry. The positive electrode slurry is then coated onto Al foil using a double-sided, double-cavity coating device. After double-sided coating, the coating is dried, cold-pressed, slit, and the positive electrode sheet is obtained.

[0411] 2. Preparation of negative electrode sheet

[0412] Conductive carbon nanotubes and binder sodium carboxymethyl cellulose were added to water to form a slurry. The slurry was coated on a Cu foil with a thickness of 13 μm to form an interface modification layer, which was used as a Na deposition current collector. The single-sided coating thickness of the interface modification layer was 3 μm.

[0413] 3. Preparation of electrolyte

[0414] In an argon-filled glove box with a water content of <1ppm, NaPF6 was added to ethylene glycol dimethyl ether and stirred until homogeneous, resulting in an electrolyte with a NaPF6 concentration of 1.0 mol / L.

[0415] 4. Separating membrane

[0416] A polyethylene film with a thickness of 12 μm.

[0417] 5. Preparation of secondary batteries

[0418] The positive electrode, separator, and negative electrode are stacked in sequence, with the separator positioned between the anode and cathode for isolation. The electrode assembly is then wound up and placed inside the casing. Simultaneously, a hydrogen-absorbing alloy sheet is fixed to the underside of the top cover, adjacent to the tab, occupying the lower plastic space. After drying, electrolyte is injected at a rate of 4 g / Ah, leaving a residual space of 0.3 mL / Ah inside the casing. After formation and settling processes, a secondary battery is produced through further assembly, electrolyte injection, formation, and aging processes.

[0419] The preparation methods of sodium-ion batteries in Examples 2-22 and Comparative Examples 1-3 are the same as those in Example 1, except that the process of preparing hydrogen storage materials is different. Examples 2-5, 7-8, and 23-24 are adjusted according to the different elements and ratios of hydrogen storage materials compared to Example 1, as shown in Table 1.

[0420] In Comparative Example 1, no hydrogen storage material was prepared, and no hydrogen storage material was set in the secondary battery. In Comparative Example 2, the hydrogen absorption platform pressure of the hydrogen storage material set in the battery was not within the scope of this application. In Comparative Example 3, the residual space inside the shell was not within the scope of this application.

[0421] Table 1

[0422] In Table 1, the hydrogen absorption pressure refers to the pressure at which the hydrogen storage material begins to absorb hydrogen, which is the minimum hydrogen absorption pressure.

[0423] The pressure-concentration isotherm (PCT) curve of the hydrogen storage material prepared in Example 1 was measured twice, with parallel sample 1 and parallel sample 2 used for the two measurements. The detailed test procedures for the two measurements are as follows:

[0424] The following measurements were taken using the H2PCT-1153 3-channel fully automated hydrogen storage material performance testing system (Yangzhou Yinghui Zhiyue):

[0425] Pressure sensors: 2 full-range absolute pressure sensors (0-10MPa) and 1 sensor (0-15MPa), with an accuracy of 0.04%FS; Temperature sensors: RT-100℃, RT-300℃, RT-500℃; The furnace can be programmed to heat up; The temperature sensors are placed outside the sample chamber; The sample chamber volume is (H15mm×12mm); The sample chamber and test pipeline are connected via quick connectors.

[0426] PCT curves and hydrogen absorption / desorption kinetics tests were conducted on the hydrogen storage material. Cylinder capacities: three 1000ml cylinders and three 150ml cylinders. The entire pipeline can withstand a pressure of 1×10⁻⁶. -6 The hydrogen pressure was -15 MPa. An Edwards vacuum pump (equipped with a hose, with exhaust gas discharged outdoors) was used. The test results are shown in Figure 24. It can be seen that the hydrogen absorption plateau pressure of the hydrogen storage material in Example 1 is 0.2 MPa, and the minimum hydrogen absorption pressure is 0.008 MPa.

[0427] The hydrogen storage material sheet prepared in Example 1 was subjected to ion polishing cross-sectional morphology (CP) image obtained by ZEISS Sigma300 scanning electron microscope, as shown in Figure 25. It can be seen that the hydrogen storage material sheet includes a substrate 101 and a hydrogen storage material layer 102 disposed on the substrate.

[0428] The internal pressure of the secondary batteries prepared in Example 1 and Comparative Example 1 was measured over time using built-in pressure sensors, as shown in Figure 26. It can be seen that the internal pressure of the battery in Example 1 of this application is consistently below 0.1 MPa, which is at a low level. In contrast, Comparative Example 1 did not add any hydrogen storage material, and the internal pressure of the battery increased significantly over time.

[0429] The internal pressure of gas generation and thermal runaway performance of the secondary batteries of Examples 1-22 and Comparative Examples 1-3 were characterized, and the characterization results are shown in Table 2.

[0430] 1. Cyclic Gas Generation Internal Pressure Test: Arrange the pipes along the sealing nail welding holes of the secondary battery prepared above. The pipe diameter is the same as that of the sealing nail holes. Connect the oil gauge along the end of the pipe. Clamp the battery with two aluminum plates. Set the initial clamping force to 3000N. Calibrate three times, with an interval of 15 minutes between each time. Then charge and discharge the battery at 1C / 1C. The temperature of all battery bodies should be monitored and the oil gauge pressure should be recorded.

[0431] 2. Thermal runaway performance test:

[0432] (1) Before testing, fully charge the secondary battery according to the following procedure: charge to 4V at 0.33C.

[0433] (2) Record the battery's main voltage, internal resistance, and weight; inspect the appearance and take photos.

[0434] (3) Place the secondary battery in a high-temperature chamber using a 15mm steel clamp, raise the temperature from RT to 100℃ at 5℃ / min and hold for 1 hour, then raise the temperature at 5℃ / min until the battery body runs out of control, and hold for 30 minutes at 5℃ every 30 minutes.

[0435] (4) Monitoring video, voltage of the battery body, temperature of the positive terminal, negative terminal, center of the large surface, barcode of the battery body, and explosion-proof port.

[0436] (5) Measure the voltage, internal resistance, and weight; inspect the appearance and take photos.

[0437] (6) Provide an experimental report. If the secondary battery does not catch fire or explode, it passes the thermal runaway test. The results are shown in Table 2.

[0438] Table 2

[0439] As shown in Table 2, in Examples 1-22 of this application, by adding specific hydrogen storage materials to the battery cells based on the pressure inside the battery cell casing, the residual space, and the partial pressure of hydrogen, the internal pressure of the battery cells can be reduced, thus lowering the risk of thermal runaway. Compared to Examples 1-22, the battery cell in Comparative Example 1 did not use hydrogen storage materials, the hydrogen absorption platform pressure of the hydrogen storage material in the battery of Comparative Example 2 is outside the range of this application, and the residual space inside the casing of Comparative Example 3 is outside the range of this application. Therefore, the internal pressure of the battery cells is higher, and the risk of thermal runaway is higher.

[0440] The differences between Examples 23 and 24 and Example 1 are shown in Table 3 below.

[0441] Table 3

[0442] It should be noted that this application is not limited to the above-described embodiments. The above embodiments are merely examples, and any embodiments with the same structure and effect as the technical concept within the scope of this application are included in the technical scope of this application. Furthermore, various modifications that can be conceived by those skilled in the art to the embodiments, and other ways of constructing by combining some of the constituent elements of the embodiments, without departing from the spirit of this application, are also included in the scope of this application.

Claims

1. A battery cell, wherein, The battery cell includes a battery body and a housing for containing the battery body. The battery body includes a positive electrode, an electrolyte, and a negative electrode. When the battery cell is charged, metal ions are released from the positive electrode and metal is formed on the negative electrode. The residual space inside the outer shell is 0.15 mL / Ah-2 mL / Ah, the pressure inside the outer shell is ≤0.65 MPa, and the partial pressure P of hydrogen inside the outer shell is in the range of 0 < P ≤ 0.65 MPa. The battery cell also includes a hydrogen storage material, which is disposed between the battery body and the outer casing, and the hydrogen absorption platform pressure of the hydrogen storage material is less than or equal to 1 MPa.

2. The battery cell of claim 1, wherein, The hydrogen absorption platform pressure of the hydrogen storage material is 0.05MPa-0.3MPa, and can be selected as 0.05MPa-0.29MPa.

3. The battery cell of claim 1 or 2, wherein, 0 < P ≤ 0.35 MPa; and / or, The pressure inside the outer shell is 0.05MPa-0.35MPa.

4. The battery cell of any one of claims 1-3, wherein, Under standard conditions, each gram of the hydrogen storage material can absorb 50 mL to 250 mL of hydrogen gas.

5. The battery cell of any one of claims 1-4, wherein, Under standard conditions, each gram of the hydrogen storage material can absorb 50 mL to 180 mL of hydrogen gas.

6. The battery cell of any one of claims 1-5, wherein, The hydrogen absorption pressure of the hydrogen storage material is 0.005MPa-0.5MPa.

7. The battery cell of any one of claims 1-6, wherein, The hydrogen absorption pressure of the hydrogen storage material is 0.005MPa-0.1MPa.

8. The battery cell of any one of claims 1-7, wherein, The volume average particle size Dv50 of the hydrogen storage material is 2μm-50μm, optionally 2μm-30μm, and further optionally 10μm-20μm.

9. The battery cell of any one of claims 1-8, wherein, The negative electrode sheet includes a negative current collector and an interface modification layer disposed on at least one side of the negative current collector, the interface modification layer including a first binder and a conductive agent.

10. The battery cell according to claim 9, wherein, The thickness of the interface modification layer is 0.5μm-5μm.

11. The battery cell according to claim 9 or 10, wherein, The interface modification layer also includes the hydrogen storage material.

12. The battery cell according to any one of claims 1-11, wherein, The negative electrode sheet includes a negative current collector and an active material layer disposed on at least one side of the negative current collector, wherein the active material layer includes an elemental active metal.

13. The battery cell according to claim 12, wherein, The active metal element includes at least one of lithium, sodium, potassium, zinc, or aluminum.

14. The battery cell according to any one of claims 1-13, wherein, In the battery cell, the amount of hydrogen storage material added is 0.1g / Ah-2g / Ah.

15. The battery cell according to any one of claims 1-14, wherein, In the battery cell, the amount of hydrogen storage material added is 0.1g / Ah-0.75g / Ah.

16. The battery cell of any one of claims 1-15, wherein, In the battery cell, the amount of hydrogen storage material added is 0.2g / Ah-0.5g / Ah.

17. The battery cell according to any one of claims 1-16, wherein, The operating voltage of the battery cell is 1.5V-4V.

18. The battery cell according to any one of claims 1-17, wherein, The working voltage of the battery cell is 1.5V-3V, and the amount of hydrogen storage material added is 0.02g / Ah-0.6g / Ah.

19. The battery cell according to any one of claims 1-18, wherein, The working voltage of the battery cell is 3V-4V, and the amount of hydrogen storage material added is 0.07g / Ah-1.6g / Ah.

20. The battery cell of any one of claims 1-19, wherein, The electrolyte includes a solvent, which includes at least one of an ether solvent or an ester solvent.

21. The battery cell of claim 20, wherein, The solvent includes ether solvents, which include at least one of 1,2-dimethoxypropane, dimethoxymethane, ethylene glycol dimethyl ether, tetrahydrofuran, 2-methyltetrahydrofuran, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, pentaethylene glycol dimethyl ether, polyethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol diethyl ether, triethylene glycol diethyl ether, tetraethylene glycol diethyl ether, pentaethylene glycol diethyl ether, ethylene glycol dibutyl ether, diethylene glycol dibutyl ether, or 1,3-dioxopentane.

22. The battery cell of any one of claims 1-21, wherein, The electrolyte includes an electrolyte salt, wherein the molar concentration of the electrolyte salt is 0.5 mol / L to 4 mol / L.

23. The battery cell according to any one of claims 1-22, wherein, The electrolyte includes an electrolyte salt, wherein the molar concentration of the electrolyte salt is 0.5 mol / L to 1.5 mol / L.

24. The battery cell of any one of claims 1-23, wherein, The electrolyte includes an electrolyte solution, and the amount of electrolyte solution injected into the battery cell is 2g / Ah-8g / Ah.

25. The battery cell of any one of claims 1-24, wherein, The electrolyte includes an electrolyte solution, and the amount of electrolyte solution injected into the battery cell is 2.4 g / Ah to 6 g / Ah.

26. The battery cell of any one of claims 1-25, wherein, The hydrogen storage material satisfies at least one of the following conditions: The hydrogen release platform pressure of the hydrogen storage material is 1 MPa-1.5 MPa; The density of the hydrogen storage material is 3 g / cm³. 2 -8.5g / cm 2 ; The operating temperature of the hydrogen storage material is -40℃ to 60℃; The BET specific surface area of ​​the hydrogen storage material is 0.5 m². 2 / g-10m 2 / g, optional 1m 2 / g-10m 2 / g; The tap density of the hydrogen storage material is 3 g / cm³. 3 -7g / cm 3 ; The compaction density of the hydrogen storage material is 4 g / cm³. 3 -8g / cm 3 ; The saturated aqueous solution of the hydrogen storage material has a pH value of 9-11 at 25°C.

27. The battery cell of any one of claims 1-26, wherein, The hydrogen storage material includes one or more of carbon-based materials and alloy materials.

28. The battery cell according to claim 27, wherein, The carbon-based material includes porous carbon.

29. The battery cell of claim 27, wherein, The alloy material includes zirconium alloys, magnesium alloys, titanium alloys, vanadium alloys, or La. x Ni y M z At least one of them, Wherein, M includes at least one of Zr, Mn, Mg, Zn, Al, Ti, Fe, Cu, Co, Y, Ca, Bi, Ce, Pr, and Nd, and 0 < x ≤ 2, 0 ≤ y ≤ 7, and 0 ≤ z ≤ 3.

30. The battery cell according to claim 29, wherein, The alloy material satisfies at least one of the following conditions: (1) The titanium alloy includes at least one of TiNi, Ti2Ni, TiFe or TiMn2; (2) The magnesium alloy includes at least one of Mg2Ni, Mg2Cu, Mg2Co, Mg2Al, Mg2Cr or Mg2Te; (3) The zirconium alloy includes at least one of ZrV2, ZrCr2 or ZrMn2; (4) The vanadium alloy includes V3TiNi 0.56 M1 m m = 0.046-0.24, M1 includes at least one of Al, Si, Fe, Cu or Zr.

31. The battery cell of claim 29, wherein, The La x Ni y M z at least one of the following conditions is met: (1) the La x Ni y M z in the chemical formula, 0.3≤x≤1; (2) The La x Ni y M z In the chemical formula, 1 ≤ y ≤ 5; (3) The La x Ni y M z In the chemical formula, 0 ≤ z ≤ 1; (4) the La x Ni y M z In the chemical formula, M includes at least one of Al, Mn, Mg, Fe, Y, Bi, Ce, Pr, and Nd.

32. The battery cell of any one of claims 1-31, wherein, The hydrogen storage material includes LaNi 3.5 M2 x1 M3 y1 M4 z1 Where x1 is 0.2-0.6, y1 is 0-1, z1 is 0.3-0.9, x1+y1+z1=1.5, M2 includes at least one of Mn or Fe, M3 includes at least one of Zr, Ti or Y, and M4 includes at least one of Al, Mg, Ca or Bi.

33. The battery cell of any one of claims 1-32, wherein, The hydrogen storage material includes La 0.5 Ni 4.5 Y 0.5 LaNi 3.5 Mn 0.2 YBi 0.3 LaNi 3.5 Mn 0.6 Y 0.4 Bi 0.5 LaNi 3.5 Mn 0.2 Y 0.4 Bi 0.9 LaTi 3.5 Fe 0.4 Zr 0.5 Bi 0.6 LaTi 3.5 Fe 0.4 Zr 0.5 Mg 0.6 LaNi 4.26 Al 0.08 Mg 0.16 La 0.43 Y 0.57 Ni 4.5 Al 0.08 Mn 0.3 LaNi 3.97 Co 0.45 Mn 0.41 Al 0.24 LaNi 3.5 Al 0.13 At least one of them.

34. The battery cell of any one of claims 1-33, wherein, The battery cell satisfies at least one of the following conditions: At 170°C, the water content in the battery cell is 200ppm-1000ppm; The positive electrode sheet includes a positive current collector and a positive active material layer disposed on at least one side of the positive current collector. The positive active material layer includes positive active material, and the mass percentage of residual alkali is 0.2%-1.5% based on the total mass of the positive active material.

35. The battery cell of any one of claims 1-34, wherein, The battery cell includes a hydrogen storage material sheet, the hydrogen storage material sheet includes a substrate and a hydrogen storage material layer disposed on at least one side of the substrate, the hydrogen storage material layer includes the hydrogen storage material.

36. The battery cell of claim 35, wherein, The hydrogen storage material sheet satisfies at least one of the following conditions: Based on the total mass of the hydrogen storage material layer, the mass percentage of the hydrogen storage material is ≥90%; The hydrogen storage material layer further includes a second binder, which includes at least one of polytetrafluoroethylene, polyacrylic acid, carboxymethyl cellulose or styrene-butadiene rubber; The matrix includes at least one of copper, nickel, aluminum, or stainless steel; The thickness of the hydrogen storage material sheet is 0.1mm-4.5mm; The thickness of the hydrogen storage material layer is 0.05mm-1.25mm; The thickness of the substrate is 10μm-150μm.

37. The battery cell according to any one of claims 1-36, wherein, The battery body includes: An electrode assembly includes the positive electrode and the negative electrode, the electrode assembly is housed within the housing, and a gap is formed between the electrode assembly and the housing; An electrolyte, comprising an electrolyte solution contained within the housing, a portion of which is immersed in the electrode assembly, and a portion of which is contained within a portion of the gap; A gas storage structure is housed within the outer casing, the gas storage structure being at least partially located in another portion of the gap, and at least a portion of the gas storage structure being the hydrogen storage material.

38. The battery cell of claim 37, wherein, The housing includes a first wall and a second wall, which are disposed opposite to each other. The first wall supports the electrode assembly, and at least a portion of the gap is formed between the second wall and the electrode assembly. At least a portion of the gas storage structure is disposed between the electrode assembly and the second wall.

39. The battery cell of claim 38, wherein, A first insulating element is provided between the second wall and the electrode assembly; The gas storage structure is disposed between the first insulating member and the second wall, and / or the gas storage structure is disposed between the first insulating member and the electrode assembly.

40. The battery cell according to claim 39, wherein, The second wall faces the side surface of the first insulator, and / or the side surface of the first insulator facing the second wall is connected to the gas storage structure, and / or the electrode assembly faces the side surface of the first insulator, and / or the side surface of the first insulator facing the electrode assembly is connected to the gas storage structure.

41. The battery cell of claim 39, wherein, An electrode space is formed between the first insulating member and the electrode assembly, the electrode space accommodating the electrode, and at least a portion of the gas storage structure is provided within the electrode space.

42. The battery cell of claim 41, wherein, The electrode space includes: a folded electrode region accommodating the electrode and a void region located around the folded electrode region, at least a portion of the gas storage structure is disposed in the folded electrode region, and / or the void region.

43. The battery cell of claim 42, wherein, Within the area of ​​the folded tab, the gas storage structure is provided in the gap between adjacent tabs and / or in the gap between the tab and the outer shell.

44. The battery cell of claim 39, wherein, The first insulating member has a receiving cavity that is open to one side of the second wall and / or to one side of the electrode assembly to receive the gas storage structure, and the receiving cavity is in communication with the gap.

45. The battery cell of claim 44, wherein, The first insulating member includes a limiting portion that protrudes toward the electrode assembly, and the accommodating cavity is formed in the limiting portion.

46. The battery cell of claim 39, wherein, The second wall is provided with an explosion-proof component, which is configured to rupture when the pressure inside the housing reaches a set condition to release the gas inside the housing. The first insulating component has a connecting portion for connecting the internal space of the housing with the explosion-proof component, and at least a portion of the gas storage structure is disposed in the connecting portion.

47. The battery cell of claim 46, wherein, The connecting portion is constructed as a connecting groove formed on the first insulating member, the connecting groove extending along the side surface of the first insulating member facing the electrode assembly to the side surface of the first insulating member away from the electrode assembly.

48. The battery cell of claim 38, wherein, The outer casing has a third wall, which is connected to the first wall and the second wall respectively, and at least part of the gas storage structure is disposed between the third wall and the electrode assembly.

49. The battery cell of claim 48, wherein, A second insulating element is provided between the third wall and the electrode assembly, and the gas storage structure is disposed between the second insulating element and the third wall, and / or, the gas storage structure is disposed between the second insulating element and the electrode assembly.

50. The battery cell of claim 49, wherein, The third wall has a side surface facing the second insulator, and / or the second insulator has a side surface facing the third wall that is connected to the gas storage structure, and / or the electrode assembly has a side surface facing the second insulator, and / or the second insulator has a side surface facing the electrode assembly that is connected to the gas storage structure.

51. The battery cell of claim 49, wherein, The second insulating member has a receiving cavity that is open to the side facing the third wall and / or the side facing the electrode assembly to receive the gas storage structure, and the receiving cavity is in communication with the gap.

52. The battery cell of claim 51, wherein, The second insulating member includes a limiting portion that protrudes toward the electrode assembly, and the accommodating cavity is formed in the limiting portion.

53. The battery cell according to claim 49, wherein, A tab space is formed between the second insulating member and the electrode assembly, the tab space accommodates the tab, and at least a portion of the gas storage structure is provided in the tab space.

54. The battery cell according to claim 53, wherein, The electrode space includes: a folded electrode region for accommodating the electrode and a void region located around the folded electrode region, with at least a portion of the gas storage structure disposed in the void region.

55. The battery cell of any one of claims 48-54, wherein, The gas storage structure located between the third wall and the electrode assembly is disposed adjacent to the second wall, and the maximum distance between the gas storage structure and the second wall is less than or equal to 5 mm.

56. An electrical device, comprising: Includes the battery cell according to any one of claims 1-55.

Images