Battery

Abstract

This application discloses a battery comprising a cell and a liquid storage device. The cell has corresponding first and second surfaces. The liquid storage device is configured to store a portion of the battery's electrolyte and includes a first liquid storage portion disposed on the second surface. The cell has a positive tab and a negative tab, which are disposed on the first surface, or the positive and negative tabs are located on adjacent sides of the cell, with one of them disposed on the first surface. This not only increases the battery's liquid retention capacity without reducing its energy density, but also facilitates the battery's ability to feed back to the cell during the later stages of long-cycle operation, improving the battery's cycle performance and preventing performance degradation caused by residual electrolyte accumulating at the bottom of the battery casing.

Description

Technical Field

[0001] This application relates to the field of battery technology, and more particularly to a battery. Background Technology

[0002] Lithium-ion batteries possess high energy density, power density, and long cycle life, playing a crucial role in wind and solar power generation and storage systems, as well as new energy vehicles. However, lithium-ion batteries consume a significant amount of electrolyte during long cycles, necessitating high electrolyte retention to prevent performance degradation in the later stages of extended cycles.

[0003] In related technologies, methods such as reducing the compaction of the positive and negative electrodes, increasing the separator thickness, or increasing the electrolyte injection volume are commonly used to improve the electrolyte retention of lithium-ion batteries. However, reducing the compaction of the positive and negative electrodes or increasing the separator thickness will reduce the energy density of the battery. At the same time, increasing the electrolyte injection volume will cause most of the injected electrolyte to accumulate at the bottom of the battery casing, making it difficult to distribute evenly. Furthermore, at high temperatures, the electrolyte-rich areas are prone to side reactions, which may induce problems such as lithium plating and deteriorate cycle performance.

[0004] Therefore, how to avoid the degradation of battery cycle performance in the later stages of long-term cycling without reducing the battery's energy density and avoiding excessive electrolyte accumulation at the bottom of the battery casing is a technical problem that urgently needs to be solved. Utility Model Content

[0005] To address the shortcomings of existing technologies, this application provides a battery that can prevent the battery's cycle performance from deteriorating in the later stages of long-term cycling without reducing the battery's energy density or causing excessive electrolyte accumulation at the bottom of the battery casing.

[0006] This application provides a battery comprising:

[0007] The battery cell has corresponding first and second surfaces;

[0008] The electrolyte reservoir is configured to store a portion of the battery's electrolyte.

[0009] The liquid storage component includes a first liquid storage part, which is disposed on the second surface;

[0010] The battery cell has a positive tab and a negative tab. The positive tab and the negative tab are located on the first surface, or the positive tab and the negative tab are located on adjacent sides of the battery cell, with one of them located on the first surface.

[0011] Furthermore, in the battery provided in this application, the liquid storage capacity value of the liquid storage device is greater than or equal to a preset first threshold and less than or equal to a preset second threshold; the ratio between the second threshold and the first threshold is greater than 1 and less than or equal to 3.75; the liquid storage capacity value is configured to characterize the amount of electrolyte stored in the liquid storage device per unit weight.

[0012] Furthermore, in the battery provided in this application, the first threshold is greater than 0 and less than or equal to 8g / g; the second threshold is greater than or equal to 8g / g and less than or equal to 30g / g.

[0013] Furthermore, in the battery provided in this application, the liquid storage capacity value satisfies: Where P is the liquid storage capacity value in g / g, and α is the oil absorption value of the liquid storage component in g / cm³. 3 β is the porosity (%) of the liquid reservoir, and V is the volume (cm³) of the liquid reservoir. 3 , where m is the mass of the liquid storage component (g).

[0014] Furthermore, in the battery provided in this application, the first contact angle of the liquid storage device with the electrolyte is higher than the second contact angle of the battery electrode with the electrolyte and / or the third contact angle of the battery separator with the electrolyte.

[0015] Furthermore, in the battery provided in this application, the first contact angle is greater than or equal to 25° and less than or equal to 50°.

[0016] Furthermore, in the battery provided in this application, the battery also includes a top cover, which is configured to encapsulate the battery cell; a first surface is provided on the side of the battery cell facing the top cover.

[0017] Furthermore, in the battery provided in this application, a positive terminal and a negative terminal are provided on the side of the top cover away from the first surface, with the positive terminal connected to the positive tab and the negative terminal connected to the negative tab.

[0018] Furthermore, in the battery provided in this application, the liquid storage component includes a second liquid storage portion disposed on the first surface and / or a third liquid storage portion disposed on the first surface;

[0019] The positive electrode tab and the negative electrode tab are both located on the first surface, the second liquid storage part is located on the side of the positive electrode tab away from the negative electrode tab, or / and the third liquid storage part is located on the side of the negative electrode tab away from the positive electrode tab.

[0020] Furthermore, in the battery provided in this application, the cell also includes a third surface and a fourth surface, the third surface and the fourth surface being the corresponding surfaces of the cell, and the liquid storage device also includes a fourth liquid storage portion disposed on the third surface and / or a fifth liquid storage portion disposed on the fourth surface.

[0021] The fourth liquid storage section is connected to the second liquid storage section, and / or the fifth liquid storage section is connected to the third liquid storage section.

[0022] Furthermore, in the battery provided in this application, the two ends of the first liquid storage section are respectively connected to the fourth liquid storage section and the fifth liquid storage section.

[0023] Furthermore, in the battery provided in this application, the thickness ratio between the second liquid reservoir and the fourth liquid reservoir is greater than or equal to 2 and less than or equal to 30; or / and,

[0024] The thickness ratio between the second and fifth liquid storage sections is greater than or equal to 2 and less than or equal to 30; or / and,

[0025] The thickness ratio between the second liquid reservoir and the first liquid reservoir is greater than or equal to 2 and less than or equal to 30; or / and,

[0026] The thickness ratio between the third and fourth liquid storage sections is greater than or equal to 2 and less than or equal to 30; or / and,

[0027] The thickness ratio between the third and fifth liquid storage sections is greater than or equal to 2 and less than or equal to 30; or / and,

[0028] The thickness ratio between the third and fourth liquid storage sections is greater than or equal to 2 and less than or equal to 30.

[0029] Furthermore, in the battery provided in this application, the thickness of the second liquid storage section and / or the thickness of the third liquid storage section are greater than or equal to 1 mm and less than or equal to 3 mm, and the thickness of the fourth liquid storage section and / or the thickness of the fifth liquid storage section and / or the thickness of the first liquid storage section are greater than or equal to 0.1 mm and less than or equal to 0.5 mm.

[0030] Furthermore, in the battery provided in this application, when the liquid storage component includes a second liquid storage section, a third liquid storage section, a fourth liquid storage section, a fifth liquid storage section, and a first liquid storage section, the second liquid storage section, the third liquid storage section, the fourth liquid storage section, the fifth liquid storage section, and the first liquid storage section are integrally formed to form the liquid storage component.

[0031] Furthermore, in the battery provided in this application, the positive terminal is connected to the positive tab using a positive adapter plate, and the negative terminal is connected to the negative tab using a negative adapter plate.

[0032] Furthermore, in the battery provided in this application, an explosion-proof valve is also provided on the top cover, which is located between the positive terminal and the negative terminal.

[0033] Furthermore, in the battery provided in this application, the battery also includes a casing;

[0034] The housing is configured to house the liquid reservoir and the battery cell.

[0035] Furthermore, in the battery provided in this application, the battery also includes a protective film configured to wrap around the casing to protect the battery cell.

[0036] Furthermore, in the battery provided in this application, the liquid storage device is one of the following: a liquid storage device made of polyethylene fiber, a liquid storage device made of polypropylene fiber, a liquid storage device made of polyester fiber, a liquid storage device made of aramid fiber, a liquid storage device made of polyurethane, a liquid storage device made of polyamide, a liquid storage device made of alkyl ethylene polymer, a liquid storage device made of polylactic acid, or a liquid storage device made of acrylate-styrene copolymer.

[0037] The battery provided in this application includes a battery cell and a liquid storage device. The battery cell has corresponding first and second surfaces. The liquid storage device is configured to store a portion of the battery's electrolyte. The liquid storage device includes a first liquid storage portion disposed on the second surface. The battery cell has a positive tab and a negative tab. The positive and negative tabs are disposed on the first surface, or the positive and negative tabs are respectively located on adjacent sides of the battery cell, with one of them disposed on the first surface. This not only increases the battery's liquid retention capacity without reducing the battery's energy density, but also facilitates the battery's ability to feed back to the battery cell in the later stages of long-term cycling, improving the battery's cycle performance and preventing performance degradation caused by the accumulation of residual electrolyte at the bottom inside the battery casing. Attached Figure Description

[0038] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0039] Figure 1 A schematic diagram of the structure of a battery provided for the prior art;

[0040] Figure 2 This is a schematic diagram of the battery structure provided in an embodiment of this application;

[0041] Figure 3 A front view of the liquid storage component provided in an embodiment of this application;

[0042] Figure 4 This is a front view of the battery after assembling the liquid storage component, as provided in the embodiments of this application.

[0043] Figure 5 This is a side view of the battery after assembling the liquid storage component, as provided in an embodiment of this application.

[0044] Figure 6 A front view of a battery provided in an embodiment of this application.

[0045] Figure label:

[0046] 100. Battery cell; 101. Positive electrode tab; 102. Negative electrode tab; 103. Positive electrode adapter; 104. Negative electrode adapter; 20. Insulating film; 200. Liquid storage component; 201. First liquid storage section; 202. Second liquid storage section; 203. Third liquid storage section; 204. Fourth liquid storage section; 205. Fifth liquid storage section; 300. Top cover; 301. Positive electrode post; 302. Negative electrode post; 303. Explosion-proof valve; 400. Housing; 500. Protective film. Detailed Implementation

[0047] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0048] It should be understood that, when used in this specification and the appended claims, the terms "comprising" and "including" indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0049] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the scope of the application. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0050] It should also be further understood that the term “and / or” as used in this application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0051] Furthermore, in this application, unless otherwise explicitly specified or limited in the embodiments, the terms "installation," "connection," "joining," and "fixing" appearing in the embodiments should be interpreted broadly. For example, a connection can be a fixed connection, a detachable connection, or an integral part; it can also be a mechanical connection, an electrical connection, etc. Of course, it can also be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication between two components, or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific implementation.

[0052] like Figure 1 As shown, this application provides a battery comprising a cell 100, an insulating film 20, a casing 400, and a protective film 500. The insulating film 20 can wrap the sides of the cell 100 to provide insulation; the insulating film 20 can also be understood as an insulating gasket. After the cell 100 is wrapped by the insulating film 20, it can be assembled into the casing 400, and the protective film 500 wraps the casing 400 to protect the cell 100.

[0053] However, the battery provided above will consume the battery during long-term cycling. In order to avoid reducing the battery's energy density and avoid excessive electrolyte accumulation at the bottom of the battery casing 400, the battery's cycle performance will be reduced in the later stages of long-term cycling.

[0054] Therefore, this application provides a battery that may include a cell 100, a liquid storage device 200, a casing 400, and a protective film 500. The liquid storage device 200 is disposed on the surface of the cell 100 and configured to store a portion of the battery's electrolyte. The liquid storage capacity of the liquid storage device 200 is between a first threshold and a second threshold, and the ratio between the second threshold and the first threshold is greater than or equal to 1 and less than or equal to 3.75. This application can be understood as... Figure 1 The insulating film 20 is replaced with a liquid storage device 200, which can increase the liquid retention of the battery without reducing the energy density of the battery. It also facilitates the battery to feed back to the cell 100 in the later stages of long cycles, improving the cycle performance of the battery and preventing the performance deterioration caused by the accumulation of residual electrolyte inside the battery casing 400 at the bottom.

[0055] Please see Figure 2 and Figure 6 , Figure 2 This is a schematic diagram of the battery structure provided in an embodiment of this application; Figure 6 A front view of a battery provided in an embodiment of this application.

[0056] like Figure 2 and Figure 6 As shown, this application provides a battery comprising:

[0057] 100 cells;

[0058] A liquid storage component 200 is disposed on the surface of the battery cell 100;

[0059] The liquid storage device 200 is configured to store a portion of the electrolyte of the battery. The liquid storage capacity value of the liquid storage device 200 is greater than or equal to a preset first threshold and less than or equal to a preset second threshold. The ratio between the second threshold and the first threshold is greater than or equal to 1 and less than or equal to 3.75. The liquid storage capacity value is configured to characterize the amount of electrolyte stored by the liquid storage device 200 per unit weight.

[0060] In this embodiment, the liquid storage component 200 can be an electrolyte-resistant, oleophilic, and insulating liquid storage component 200, thereby avoiding additional chemical reactions in the battery after the introduction of the liquid storage component 200. Specifically, the liquid storage component 200 can be disposed in the extra space between the cell 100 and the battery casing 400. This can also be understood as replacing the original insulating film 20 with the liquid storage component 200. The insulating film 20 does not have liquid storage capacity; its liquid storage capacity value can be understood as 0. This application provides a solution that replaces the original insulating film 20 with a liquid storage component 200, thereby improving the battery's cycle performance in the mid-to-late stages without reducing the battery's energy density. The liquid storage component 200 can be understood as a component similar to a sponge structure, i.e., a sponge-structured liquid storage component 200.

[0061] Specifically, the material of the liquid storage component 200 may include at least one of polyethylene fiber, polypropylene fiber, polyester fiber, aramid, polyurethane, polyamide, alkyl ethylene polymer, polylactic acid, and acrylate-styrene copolymer.

[0062] Furthermore, the liquid storage component 200 is at least one of the following: a liquid storage component 200 made of polyethylene fiber, a liquid storage component 200 made of polypropylene fiber, a liquid storage component 200 made of polyester fiber, a liquid storage component 200 made of aramid fiber, a liquid storage component 200 made of polyurethane, a liquid storage component 200 made of polyamide, a liquid storage component 200 made of alkyl ethylene polymer, a liquid storage component 200 made of polylactic acid, and a liquid storage component 200 made of acrylate-styrene copolymer.

[0063] By testing the liquid storage capacity of the liquid storage device 200, it can be determined that the liquid storage capacity of the liquid storage device 200 is greater than or equal to a preset first threshold and less than or equal to a preset second threshold; the ratio between the second threshold and the first threshold is greater than or equal to 1 and less than or equal to 3.75. The first threshold can be understood as the minimum liquid storage capacity of the liquid storage device 200, and the second threshold can be understood as the maximum liquid storage capacity of the liquid storage device 200. The units for the liquid storage capacity, the first threshold, and the second threshold can be g / g.

[0064] For example, the ratio between the second threshold and the first threshold can be 1, 1.25, 1.5, 1.75, 2, 2.25, 2.5, 3, 3.5, 3.75, etc.

[0065] The battery provided in this application includes a cell 100 and a liquid storage device 200. The liquid storage device 200 is disposed on the surface of the cell 100 and configured to store a portion of the electrolyte of the battery. The liquid storage capacity value of the liquid storage device 200 is between a first threshold and a second threshold. The ratio between the second threshold and the first threshold is greater than or equal to 1 and less than or equal to 3.75. This not only increases the liquid retention of the battery without reducing the energy density of the battery, but also facilitates the battery to provide feedback to the cell 100 in the later stages of long-term cycling, thereby improving the cycle performance of the battery and avoiding the performance degradation caused by the accumulation of residual electrolyte inside the battery casing 400 at the bottom.

[0066] In some embodiments, such as Figure 2 and Figure 6 As shown, this application also provides a battery comprising:

[0067] The battery cell 100 has corresponding first and second surfaces;

[0068] The liquid storage unit 200 is configured to store a portion of the battery's electrolyte;

[0069] The liquid storage component 200 includes a first liquid storage part 201, which is disposed on the second surface;

[0070] The battery cell 100 is provided with a positive tab 101 and a negative tab 102. The positive tab 101 and the negative tab 102 are provided on the first surface, or the positive tab 101 and the negative tab 102 are respectively located on adjacent sides of the battery cell 100 and one of them is provided on the first surface.

[0071] Specifically, the battery provided in this application includes a cell 100 and a liquid storage device 200. The cell 100 has corresponding first and second surfaces. The liquid storage device 200 is configured to store a portion of the electrolyte of the battery. The liquid storage device 200 includes a first liquid storage portion 201 disposed on the second surface. The cell 100 has a positive electrode tab 101 and a negative electrode tab 102. The positive electrode tab 101 and the negative electrode tab 102 are disposed on the first surface, or the positive electrode tab 101 and the negative electrode tab 102 are respectively located on adjacent sides of the cell 100 and one of them is disposed on the first surface. This not only increases the liquid retention of the battery without reducing the energy density of the battery, but also facilitates the battery to feed back to the cell 100 in the later stages of long-term cycling, improving the cycle performance of the battery and avoiding the performance deterioration caused by the accumulation of residual electrolyte inside the battery casing at the bottom.

[0072] Furthermore, in some embodiments, the first threshold is greater than 0 and less than or equal to 8 g / g; the second threshold is greater than or equal to 8 g / g and less than or equal to 30 g / g.

[0073] In this embodiment, the minimum liquid storage capacity of the liquid storage device 200 can be greater than 0 and less than or equal to 8 g / g, and the maximum liquid storage capacity of the liquid storage device 200 can be greater than or equal to 8 g / g and less than or equal to 30 g / g.

[0074] Specifically, the liquid storage capacity of the liquid storage component 200 can be between 8g / g and 30g / g, with the first threshold being 8g / g and the second threshold being 30g / g. This not only ensures that the battery's cycle capacity does not change in the mid-to-late stages, but also avoids the battery's performance degradation and excessive cost caused by adding too much electrolyte in the early stages.

[0075] In some embodiments, the liquid storage capacity value satisfies: Where P is the liquid storage capacity value, α is the oil absorption value of the liquid storage component 200, β is the porosity of the liquid storage component 200, V is the volume of the liquid storage component 200, and m is the mass of the liquid storage component 200.

[0076] In this embodiment, the electrolyte storage capacity value is configured to characterize the amount of electrolyte stored in the electrolyte storage component 200 per unit weight. It is characterized by the oil absorption value, porosity, volume, and weight of the electrolyte storage component 200. This allows for more precise battery configuration, enabling an increase in electrolyte retention without reducing the battery's energy density. It also facilitates feedback to the cell 100 during the later stages of long-cycle operation, improving battery cycle performance and preventing performance degradation caused by residual electrolyte accumulating at the bottom of the battery casing 400. The volume of the electrolyte storage component 200 can be calculated from its length, width, and thickness. The unit for the electrolyte storage capacity value can be g / g, and the unit for the oil absorption value can be g / cm³. 3 The volume of the liquid storage unit 200 can be expressed in cm³. 3 The mass of the liquid storage component 200 can be expressed in grams.

[0077] Oil absorption value refers to the ability of the reservoir 200 to absorb electrolyte, which can be characterized by the volume of electrolyte absorbed per unit mass of reservoir 200. Various methods exist for determining oil absorption value, including the Piran method, the uniform absorption method, and the static method. In some cases, oil absorption value can also be determined using an oil absorption value tester, which determines the amount of oil absorbed by the sample by detecting changes in torque. Porosity refers to the percentage of pore volume to total volume in a material and is an important parameter for measuring the density of the reservoir 200; porosity refers to the percentage of pore volume to total volume within a material.

[0078] In some embodiments, the first contact angle of the reservoir 200 with the electrolyte is higher than the second contact angle of the battery electrode with the electrolyte and / or the third contact angle of the battery separator with the electrolyte.

[0079] Specifically, the contact angle is the angle between the tangent of the liquid-gas interface shape and the solid surface at the three-phase contact point when a liquid and a solid surface intersect. The contact angle reflects the wettability of the liquid on the solid surface, that is, the degree to which the liquid spreads on the solid surface. The smaller the contact angle, the better the wettability of the liquid on the solid surface; conversely, the larger the contact angle, the worse the wettability.

[0080] In this embodiment, the first contact angle characterizes the degree of electrolyte spreading on the surface of the storage container 200, the second contact angle characterizes the degree of electrolyte spreading on the surface of the battery electrodes, and the third contact angle characterizes the degree of electrolyte spreading on the surface of the battery separator. The first contact angle is higher than the second contact angle and / or the third contact angle, which is more beneficial for the battery in the later stages of cycling. When the electrolyte inside the cell 100 is insufficient, the electrodes and separator can absorb the electrolyte stored in the storage container 200, thereby improving the battery's cycle performance. The battery electrodes and separator can be located inside the cell 100, and the storage container 200 can absorb and store residual electrolyte outside the cell 100.

[0081] In some embodiments, the first contact angle is greater than or equal to 25° and less than or equal to 50°.

[0082] In this embodiment, the first contact angle of the liquid storage device 200 with the electrolyte is greater than or equal to 25° and less than or equal to 50°. At this time, the minimum value of the second contact angle and / or the third contact angle provided in this application can be less than 25°, and the maximum value of the second contact angle and / or the third contact angle can be less than 50°.

[0083] Specifically, the differences between the first and second contact angles, and between the first and third contact angles, are relatively small. This is more beneficial for the battery in the later stages of cycling, when the electrolyte inside the cell 100 is insufficient. The electrodes and separator can absorb the electrolyte stored in the reservoir 200, thereby improving the battery's cycle performance. The differences can be 0.05, 0.1, 0.15, 0.2, 0.25, etc., specifically between 0 and 1.

[0084] In some embodiments, such as Figure 3 , Figure 4 , Figure 5 and Figure 6As shown, the battery cell 100 includes a first surface, and the liquid storage component 200 includes a second liquid storage portion 202 disposed on the first surface and / or a third liquid storage portion 203 disposed on the first surface; wherein, a positive electrode tab 101 and a negative electrode tab 102 are disposed on the first surface, the second liquid storage portion 202 is located on the side of the positive electrode tab 101 away from the negative electrode tab 102, and / or the third liquid storage portion 203 is located on the side of the negative electrode tab 102 away from the positive electrode tab 101.

[0085] In this embodiment, as Figure 3 , Figure 4 , Figure 5 and Figure 6 As shown, the first surface can be located on the top of the cell 100, that is, the top of the cell 100 can be provided with a positive tab 101 and a negative tab 102. The positive tab 101 and the negative tab 102 can be symmetrically arranged on the top. The liquid storage device 200 can include a second liquid storage section 202 and a third liquid storage section 203. The second liquid storage section 202 and the third liquid storage section 203 can be arranged in an empty position on the top of the cell 100 and are not located below the explosion-proof valve 303 of the battery. This not only avoids interference with the opening of the explosion-proof valve 303, but also, being close to the tabs of the battery, is more conducive to the battery in the later stages of cycling. When the electrolyte inside the cell 100 is insufficient, the electrode and the separator can absorb the electrolyte stored in the liquid storage device 200, thereby improving the cycle performance of the battery.

[0086] In some embodiments, such as Figure 3 , Figure 4 , Figure 5 and Figure 6 As shown, the battery cell 100 also includes a third surface and a fourth surface, the third surface and the fourth surface being corresponding surfaces of the battery cell 100. The liquid storage component 200 also includes a fourth liquid storage portion 204 disposed on the third surface and / or a fifth liquid storage portion 205 disposed on the fourth surface; wherein, the fourth liquid storage portion 204 is connected to the second liquid storage portion 202, and / or the fifth liquid storage portion 205 is connected to the third liquid storage portion 203.

[0087] In this embodiment, as Figure 3 , Figure 4 , Figure 5 and Figure 6As shown, the third and fourth surfaces can be two corresponding sides of the battery cell 100, which can be understood as the left and right sides. The liquid storage component 200 can include a fourth liquid storage section 204 and a fifth liquid storage section 205. The fourth liquid storage section 204 can be located on the left side of the battery cell 100, and the fifth liquid storage section 205 can be located on the right side of the battery cell 100. Both the fourth liquid storage section 204 and the fifth liquid storage section 205 can extend upward to connect the fourth liquid storage section 204 with the second liquid storage section 202 and the fifth liquid storage section 205 with the third liquid storage section 203. At the same time, both the fourth liquid storage section 204 and the fifth liquid storage section 205 can extend downward to approach the bottom of the battery cell 100, thereby preventing residual electrolyte in the battery casing 400 from accumulating at the bottom.

[0088] In some embodiments, the positive electrode 101 and the negative electrode 102 can be disposed on different sides of the battery cell 100. That is, the positive electrode 101 can be disposed on the first surface and the negative electrode 102 can be disposed on the third surface; or the positive electrode 101 can be disposed on the first surface and the negative electrode 102 can be disposed on the fourth surface; or the positive electrode 101 can be disposed on the first surface and the negative electrode 102 can be disposed on the second surface; or the positive electrode 101 can be disposed on the third surface and the negative electrode 102 can be disposed on the first surface; or the positive electrode 101 can be disposed on the third surface and the negative electrode 102 can be disposed on the fourth surface; or the positive electrode 101 can be disposed on the third surface and the negative electrode 102 can be disposed on the fourth surface. The negative electrode tab 102 can be disposed on the second surface; or the positive electrode tab 101 can be disposed on the fourth surface and the negative electrode tab 102 can be disposed on the first surface; or the positive electrode tab 101 can be disposed on the fourth surface and the negative electrode tab 102 can be disposed on the third surface; or the positive electrode tab 101 can be disposed on the fourth surface and the negative electrode tab 102 can be disposed on the second surface; or the positive electrode tab 101 can be disposed on the second surface and the negative electrode tab 102 can be disposed on the first surface; or the positive electrode tab 101 can be disposed on the second surface and the negative electrode tab 102 can be disposed on the third surface; or the positive electrode tab 101 can be disposed on the second surface and the negative electrode tab 102 can be disposed on the fourth surface.

[0089] It should be noted that the positive tab 101 and the negative tab 102 can be located on the same side of the battery cell 100. That is, the positive tab 101 and the negative tab 102 can be located on the first surface, the third surface, the fourth surface, or the second surface at the same time. The positions of the positive tab 101 and the negative tab 102 can be selected according to the actual application, and this application does not make specific limitations.

[0090] In some embodiments, such as Figure 3 , Figure 4 , Figure 5 and Figure 6As shown, the battery cell 100 also includes a second surface, and the liquid storage component 200 also includes a first liquid storage section 201; wherein, the second surface and the first surface are the corresponding surfaces of the battery cell 100, and the two ends of the first liquid storage section 201 are respectively connected to the fourth liquid storage section 204 and the fifth liquid storage section 205.

[0091] In this embodiment, the second surface can be located at the bottom of the battery cell 100. The liquid storage component 200 also includes a first liquid storage section 201, which can be disposed at the bottom of the battery cell 100 and connected to the fourth liquid storage section 204 and the fifth liquid storage section 205 respectively. This allows for the adsorption and storage of residual electrolyte within the battery casing 400, preventing electrolyte accumulation at the bottom. The width D of the first liquid storage section 201 along both sides of the battery cell 100 can be less than or equal to the thickness W of the battery cell 100.

[0092] In some embodiments, the thickness ratio between the second liquid storage section 202 and the fourth liquid storage section 204 is greater than or equal to 2 and less than or equal to 30; or / and, the thickness ratio between the second liquid storage section 202 and the fifth liquid storage section 205 is greater than or equal to 2 and less than or equal to 30; or / and, the thickness ratio between the second liquid storage section 202 and the first liquid storage section 201 is greater than or equal to 2 and less than or equal to 30; or / and, the thickness ratio between the third liquid storage section 203 and the fourth liquid storage section 204 is greater than or equal to 2 and less than or equal to 30; or / and, the thickness ratio between the third liquid storage section 203 and the fifth liquid storage section 205 is greater than or equal to 2 and less than or equal to 30; or / and, the thickness ratio between the third liquid storage section 203 and the fourth liquid storage section 204 is greater than or equal to 2 and less than or equal to 30.

[0093] In this embodiment, the thickness ratios between the second liquid storage section 202 and the fourth liquid storage section 204, the second liquid storage section 202 and the fifth liquid storage section 205, the second liquid storage section 202 and the first liquid storage section 201, the third liquid storage section 203 and the fourth liquid storage section 204, the third liquid storage section 203 and the fifth liquid storage section 205, and the third liquid storage section 203 and the fourth liquid storage section 204 are set between 2 and 30. This achieves the following without increasing the battery volume: not only can the residual electrolyte in the battery casing 400 be better prevented from accumulating at the bottom, but it also allows the second liquid storage section 202 and the third liquid storage section 203 to store more electrolyte, which in turn facilitates the electrolyte to enter the electrode from top to bottom better during the later stages of the cycle.

[0094] Furthermore, in some embodiments, the thickness of the second liquid storage section 202 and the thickness of the third liquid storage section 203 are greater than or equal to 1 mm and less than or equal to 3 mm, and the thickness of the fourth liquid storage section 204, the thickness of the fifth liquid storage section 205, and the thickness of the first liquid storage section 201 are greater than or equal to 0.1 mm and less than or equal to 0.5 mm.

[0095] In some embodiments, the first liquid storage section 201, the second liquid storage section 202, the third liquid storage section 203, the fourth liquid storage section 204, and the fifth liquid storage section 205 are integrally formed to form the liquid storage component 200.

[0096] In this embodiment, the first liquid storage section 201, the second liquid storage section 202, the third liquid storage section 203, the fourth liquid storage section 204 and the fifth liquid storage section 205 are integrally formed to form the liquid storage component 200, which facilitates the electrolyte to enter the electrode plate from top to bottom better during the later stage of the cycle.

[0097] In some embodiments, such as Figure 6 As shown, the battery also includes a top cover 300; wherein the top cover 300 is configured to encapsulate a first surface, and a positive terminal 301 and a negative terminal 302 are provided on the side of the top cover 300 away from the first surface, the positive terminal 301 being connected to the positive tab 101, and the negative terminal 302 being connected to the negative tab 102.

[0098] In this embodiment, the top cover 300 can be made of aluminum and can be manufactured through processes such as stamping, injection molding, and welding. The top cover 300 is provided with a positive terminal 301 and a negative terminal 302 for electrically connecting the positive and negative terminals inside the battery to an external circuit. The positive terminal 301 and the negative terminal 302 are respectively connected to the positive tab 101 and the negative tab 102, forming a charging and discharging circuit, enabling the battery to effectively exchange energy with an external load.

[0099] In some embodiments, such as Figure 6 As shown, the positive terminal 301 is connected to the positive terminal tab 101 via a positive adapter piece 103, and the negative terminal 302 is connected to the negative terminal tab 102 via a negative adapter piece 104. In this embodiment, the positive terminal tab 101 and the positive terminal 301 are welded together via the positive adapter piece 103, while the positive terminal tab 101 and the negative terminal 302 are welded together via the negative adapter piece 104.

[0100] In some embodiments, such as Figure 6 As shown, the top cover 300 is also equipped with an explosion-proof valve 303, which is located between the positive terminal 301 and the negative terminal 302.

[0101] The explosion-proof valve 303 is a key safety device used to prevent batteries from exploding due to overpressure or overheating during charging, discharging, or abnormal operating conditions. Its main function is to automatically open the valve and release the internal high-pressure gas when the internal pressure or temperature of the battery exceeds the set value, thereby achieving the purpose of explosion prevention.

[0102] In some embodiments, such as Figure 2 and Figure 6 As shown, the battery also includes a housing 400; wherein the housing 400 is configured to assemble the liquid reservoir 200 and the battery cell 100.

[0103] In this embodiment, after the liquid storage component 200 is disposed on the surface of the cell 100, it can be assembled into the cavity of the housing 400 along with the cell 100. At the same time, after the cell 100 is filled with electrolyte, the electrolyte will overflow into the cavity and be absorbed and stored by the liquid storage component 200 in the cavity. This allows the battery to provide feedback to the cell 100 in the later stages of long-term cycling, improving the cycle performance of the battery and avoiding the performance deterioration caused by the accumulation of residual electrolyte at the bottom inside the battery housing 400.

[0104] In some embodiments, the battery further includes a protective film 500 configured to wrap around the housing 400 to protect the cell 100.

[0105] In this embodiment, the protective film 500 can be a Mylar film, which protects the battery cell 100 from scratches or short circuits during assembly. Simultaneously, the Mylar film also serves as a sealant and insulator, thereby ensuring the stability and safety of the electrolyte inside the battery. For example, the Mylar film can prevent electrolyte leakage, and by designing its structure (such as a micro-convex structure), it can improve the injection efficiency and wetting effect. The Mylar film is an oriented polyester film with excellent physical and chemical properties, such as chemical resistance, dimensional stability, and thermal stability.

[0106] The battery provided in this application will be described in detail below.

[0107] Provided separately Figure 1 The battery shown, and three sets Figure 2The batteries shown can be defined as Comparative Example 1, Example 1, Example 2, and Example 3, respectively. In Comparative Example 1, an insulating film 20 is used between the battery casing and the battery cell. In Examples 1, 2, and 3, the liquid storage device 200 is located on both sides, the bottom, and the top of the battery cell 100. The liquid storage capacity of the liquid storage device 200 in Example 1 is 15 and the first contact angle is 34°; the liquid storage capacity of the liquid storage device 200 in Example 2 is 8 and the first contact angle is 46°; and the liquid storage capacity of the liquid storage device 200 in Example 3 is 20 and the first contact angle is 31°.

[0108] The batteries provided in Comparative Example 1, Example 1, Example 2, and Example 3 were subjected to 2000 constant current charge-discharge cycles at 45°C and a rate of 1.0C (nominal capacity). The capacity retention rate (C%) after 2000 cycles was calculated as (discharge capacity of the 2000th cycle / initial discharge capacity) × 100%. The cycle capacities of Comparative Example 1, Example 1, Example 2, and Example 3 were 74.5%, 81.6%, 82.3%, and 83.7%, respectively. It can be seen that by setting a liquid storage device on the surface of the battery cell, this application can increase the liquid retention of the battery without reducing the energy density of the battery. It also facilitates the battery to feed back to the cell in the later stages of long cycles, thereby improving the cycle performance of the battery and avoiding the performance deterioration caused by the accumulation of residual electrolyte inside the battery casing at the bottom.

[0109] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and these modifications or substitutions should all be covered within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A battery, characterized by, include: The battery cell (100) has a corresponding first surface and a second surface; A liquid storage device (200) is configured to store a portion of the electrolyte of the battery; The liquid storage component (200) includes a first liquid storage part (201), which is disposed on the second surface; The battery cell (100) is provided with a positive electrode tab (101) and a negative electrode tab (102). The positive electrode tab (101) and the negative electrode tab (102) are provided on the first surface, or the positive electrode tab (101) and the negative electrode tab (102) are respectively located on adjacent sides of the battery cell (100) and one of them is provided on the first surface.

2. The battery of claim 1, wherein, The liquid storage capacity value of the liquid storage device (200) is greater than or equal to a preset first threshold and less than or equal to a preset second threshold; the ratio between the second threshold and the first threshold is greater than 1 and less than or equal to 3.75; the liquid storage capacity value is configured to characterize the amount of electrolyte stored by the liquid storage device (200) per unit weight.

3. The battery of claim 2, wherein, The first threshold is greater than 0 and less than or equal to 8 g / g; the second threshold is greater than or equal to 8 g / g and less than or equal to 30 g / g.

4. The battery of claim 2, wherein, The liquid storage capacity value satisfies: wherein P is the liquid storage capacity value g / g, a is the oil absorption value g / cm3 of the liquid storage member (200) 3 , β is the porosity % of the liquid storage member (200), V is the volume cm3 of the liquid storage member (200) 3 , and m is the mass g of the liquid storage member (200).

5. The battery of claim 1, wherein, The first contact angle of the reservoir (200) with the electrolyte is higher than the second contact angle of the battery electrode with the electrolyte and / or the third contact angle of the battery separator with the electrolyte.

6. The battery of claim 5, wherein, The first contact angle is greater than or equal to 25° and less than or equal to 50°.

7. The battery of any one of claims 1-6, wherein, The battery also includes a top cover (300) configured to encapsulate the cell (100); the first surface is located on the side of the cell (100) facing the top cover (300).

8. The battery of claim 7, wherein, The top cover (300) has a positive terminal (301) and a negative terminal (302) on the side away from the first surface. The positive terminal (301) is connected to the positive tab (101), and the negative terminal (302) is connected to the negative tab (102).

9. The battery of any one of claims 1-6, wherein, The liquid storage component (200) includes a second liquid storage portion (202) disposed on the first surface and / or a third liquid storage portion (203) disposed on the first surface. The positive electrode tab (101) and the negative electrode tab (102) are both disposed on the first surface, the second liquid storage part (202) is located on the side of the positive electrode tab (101) away from the negative electrode tab (102), and / or the third liquid storage part (203) is located on the side of the negative electrode tab (102) away from the positive electrode tab (101).

10. The battery of claim 9, wherein, The battery cell (100) further includes a third surface and a fourth surface, the third surface and the fourth surface being the corresponding surfaces of the battery cell (100), and the liquid storage device (200) further includes a fourth liquid storage part (204) disposed on the third surface and / or a fifth liquid storage part (205) disposed on the fourth surface. The fourth liquid storage section (204) is connected to the second liquid storage section (202), and / or the fifth liquid storage section (205) is connected to the third liquid storage section (203).

11. The battery of claim 10, wherein, The two ends of the first liquid storage section (201) are respectively connected to the fourth liquid storage section (204) and the fifth liquid storage section (205).

12. The battery of claim 10, wherein, The thickness ratio between the second liquid storage section (202) and the fourth liquid storage section (204) is greater than or equal to 2 and less than or equal to 30; or / and, The thickness ratio between the second liquid storage section (202) and the fifth liquid storage section (205) is greater than or equal to 2 and less than or equal to 30; or / and, The thickness ratio between the second liquid storage section (202) and the first liquid storage section (201) is greater than or equal to 2 and less than or equal to 30; or / and, The thickness ratio between the third liquid storage section (203) and the fourth liquid storage section (204) is greater than or equal to 2 and less than or equal to 30; or / and, The thickness ratio between the third liquid storage section (203) and the fifth liquid storage section (205) is greater than or equal to 2 and less than or equal to 30; or / and, The thickness ratio between the third liquid storage section (203) and the fourth liquid storage section (204) is greater than or equal to 2 and less than or equal to 30.

13. The battery of claim 12, wherein, The thickness of the second liquid storage section (202) and / or the thickness of the third liquid storage section (203) is greater than or equal to 1 mm and less than or equal to 3 mm, and the thickness of the fourth liquid storage section (204) and / or the thickness of the fifth liquid storage section (205) and / or the thickness of the first liquid storage section (201) is greater than or equal to 0.1 mm and less than or equal to 0.5 mm.

14. The battery of claim 11, wherein, When the liquid storage component includes a second liquid storage section (202), a third liquid storage section (203), a fourth liquid storage section (204), a fifth liquid storage section (205), and a first liquid storage section (201), the first liquid storage section (201), the second liquid storage section (202), the third liquid storage section (203), the fourth liquid storage section (204), and the fifth liquid storage section (205) are integrally formed to form the liquid storage component (200).

15. The battery of claim 8, wherein, The positive terminal (301) is connected to the positive tab (101) via a positive adapter (103), and the negative terminal (302) is connected to the negative tab (102) via a negative adapter (104).

16. The battery of claim 8, wherein, The top cover (300) is also provided with an explosion-proof valve (303), which is located between the positive terminal (301) and the negative terminal (302).

17. The battery of any one of claims 1-6, wherein, The battery also includes a casing (400). The housing (400) is configured to assemble the liquid reservoir (200) and the battery cell (100).

18. The battery of claim 17, wherein, The battery also includes a protective film (500) configured to wrap around the housing (400) to protect the cell (100).

19. The battery of any one of claims 1-6, wherein, The liquid storage member (200) is one of a polyethylene fiber material liquid storage member (200), a polypropylene fiber material liquid storage member (200), a polyester fiber material liquid storage member (200), an aramid fiber material liquid storage member (200), a polyurethane material liquid storage member (200), a polyamide material liquid storage member (200), an alkyl ethylene polymer material liquid storage member (200), a polylactic acid material liquid storage member (200), and an acrylate-styrene copolymer material liquid storage member (200).

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