Electrode sheet, battery, and electric device

Abstract

An electrode sheet, a battery, and an electric device. The electrode sheet comprises: a current collector layer and an active layer. The active layer is arranged on the surface of the current collector layer, and the active layer comprises active particles and liquid retaining particles. The liquid retaining particles each comprise a core and a shell, the shell is arranged around the outer periphery of the core, the shell comprises multiple sub-particles, and each sub-particle is provided with a capillary pore.

Description

Electrode plates, batteries and electrical equipment

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on March 5, 2024, with application number 2024102509039 and application name “Electrode Plate, Battery and Electrical Equipment”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of battery technology, and in particular to an electrode plate, a battery, and an electrical device. Background Art

[0003] During the battery's charge and discharge process, active ions in the electrolyte penetrate the electrode material of the electrode plate and react with the active substances therein, releasing electrons. If the electrode plate has poor electrolyte wettability, the electrolyte will be lost or unevenly distributed during the charge and discharge process, thereby affecting the battery's energy efficiency and cycle capacity retention. Therefore, improving the electrolyte retention capacity of the electrode plate is one of the important means to improve battery performance. Summary of the Invention

[0004] In view of this, the present application provides an electrode plate, a battery and an electrical device, wherein the electrode plate has good liquid retention performance.

[0005] The present application provides an electrode plate, which includes active particles and liquid-retaining particles; the liquid-retaining particles include an inner core and an outer shell, the outer shell is arranged around the outer periphery of the inner core, and the outer shell includes multiple sub-particles, each sub-particle has capillaries.

[0006] The present application provides a battery, which includes: a positive electrode sheet, a diaphragm, a negative electrode sheet and an electrolyte, wherein the diaphragm is arranged on one side of the positive electrode sheet; the negative electrode sheet is arranged on the side of the diaphragm away from the positive electrode sheet, and at least one of the positive electrode sheet and the negative electrode sheet is the electrode sheet provided in the present application; the electrolyte at least soaks part of the positive electrode sheet and part of the negative electrode sheet.

[0007] The present application provides an electrical device, which includes: a device body and a battery provided in the present application, wherein the battery supplies power to the device body.

[0008] In the present application, the electrode plate includes a current collector layer and an active layer that are stacked, and the active layer is arranged on the surface of the current collector layer. The current collector layer can carry the active layer and collect and output the current generated by the active particles, thereby realizing the concentration and transmission of current. In the present application, the active layer includes active particles and liquid-retaining particles. The liquid-retaining particles include an inner core and an outer shell arranged around the outer periphery of the inner core. The outer shell is composed of a plurality of sub-particles, and each of the sub-particles has capillaries. When the electrode plate is assembled in a battery, each of the capillaries can be used to absorb electrolyte, so that the outer shell of the liquid-retaining particle has a plurality of "tentacles", that is, the capillaries of the outer shell absorb electrolyte like a straw and store the electrolyte on the inner core. The liquid-retaining particles have a high liquid-retaining performance, which improves the ability of the electrode plate to store electrolyte, so that the electrode plate has a better wettability to the electrolyte. When the battery is charged and discharged, the active particles in the electrode plate can effectively contact the electrolyte, and the active ions in the electrolyte can chemically react with the active particles in the active layer and release electrons. The electrode plate has good liquid retention performance, which in turn improves the cycle performance and energy efficiency of the battery when the electrode plate is used in the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0010] FIG1 is a schematic structural diagram of liquid-retaining particles according to an embodiment of the present application;

[0011] FIG2 is a schematic structural diagram of a sub-particle according to an embodiment of the present application;

[0012] FIG3 is a schematic structural diagram of an electrode plate according to an embodiment of the present application;

[0013] FIG4 is an electron microscope image of an electrode sheet according to an embodiment of the present application;

[0014] FIG5 is a schematic structural diagram of a battery according to an embodiment of the present application;

[0015] FIG6 is a circuit block diagram of an electric device according to an embodiment of the present application;

[0016] FIG7 is a schematic structural diagram of an electrical device according to an embodiment of the present application.

[0017] Description of reference numerals:

[0018] 100-liquid-retaining particles, 110-core, 120-shell, 121-sub-particles, 122-capillaries, 200-electrode pole piece, 210-current collector layer, 220-active layer, 300-battery, 310-positive pole piece, 320-diaphragm, 330-negative pole piece, 340-electrolyte, 400-electrical equipment, 410-equipment body. DETAILED DESCRIPTION

[0019] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0020] The terms "first," "second," and the like in the specification and claims of this application and the accompanying drawings are used to distinguish between different objects, not to describe a particular order. Furthermore, the terms "including," "having," and any variations thereof, are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or apparatus comprising a series of steps or elements is not limited to the listed steps or elements but may optionally include steps or elements not listed, or may optionally include other steps or elements inherent to the process, method, product, or apparatus.

[0021] References herein to "embodiments" or "implementations" mean that a particular feature, structure, or characteristic described in connection with the embodiments or implementations may be included in at least one embodiment of the present application. The appearance of such phrases in various places in the specification does not necessarily refer to the same embodiment, nor do they constitute independent or alternative embodiments that are mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0022] During the battery's charge and discharge process, active ions in the electrolyte penetrate the electrode material of the electrode plate and react with the active substances therein, releasing electrons. If the electrode plate has poor electrolyte wettability, the electrolyte will be lost or unevenly distributed during the charge and discharge process, thereby affecting the battery's energy efficiency and cycle capacity retention. Therefore, improving the electrolyte retention capacity of the electrode plate is one of the important means to improve battery performance.

[0023] Commonly, the porosity of the electrode sheets is increased through methods such as increasing roller pressing to improve their fluid retention. However, it is difficult to uniformly control the size of the pores, resulting in poor stability between batches of electrode sheets. Furthermore, high-swelling binders are added to the electrode sheets to create more channels within them, thereby improving their fluid retention. However, excessive swelling can increase stress within the battery, hindering the battery's later cycling.

[0024] Please refer to Figures 1 to 4. The present application provides an electrode plate 200, which includes: a current collector layer 210 and an active layer 220. The active layer 220 is arranged on the surface of the current collector layer 210. The active layer 220 includes active particles (not shown) and liquid-retaining particles 100. The liquid-retaining particles 100 include: a core 110 and a shell 120. The shell 120 is arranged around the periphery of the core 110. The shell 120 includes a plurality of sub-particles 121, and each sub-particle 121 has a capillary pore 122.

[0025] It can be understood that the active layer 220 and the current collector layer 210 are stacked.

[0026] Optionally, the electrode plate 200 may be a positive electrode plate 310 or a negative electrode plate 330 .

[0027] Optionally, in some embodiments, the active layer 220 is disposed on one surface of the current collector layer 210 ; in other embodiments, two active layers 220 are respectively disposed on two opposite surfaces of the current collector layer 210 .

[0028] It can be understood that the liquid-retaining particles 100 are applied to the electrode plate 200 and assembled in the battery 300 ; the battery 300 includes the electrode plate 200 and the electrolyte 340 , and the electrolyte 340 at least partially soaks the electrode plate 200 .

[0029] It can be understood that the liquid-retaining particles 100 are of a core-shell structure.

[0030] In this embodiment, the electrode plate 200 includes a stacked current collector layer 210 and an active layer 220, with the active layer 220 disposed on the surface of the current collector layer 210. The current collector layer 210 can support the active layer 220 and collect and output the current generated by the active particles, thereby achieving current concentration and transmission. In this embodiment, the active layer 220 includes active particles and liquid-retaining particles 100. The liquid-retaining particles 100 include an inner core 110 and an outer shell 120 disposed around the outer periphery of the inner core 110. The outer shell 120 is composed of a plurality of sub-particles 121, and each sub-particle 121 has a capillary pore 122. When the electrode plate 200 is assembled in the battery 300, each of the capillaries 122 can be used to absorb the electrolyte 340, so that the shell 120 of the liquid-retaining particle 100 has multiple "tentacles." That is, the capillaries 122 of the shell 120 absorb the electrolyte 340 like a straw and store the electrolyte 340 on the core 110. The liquid-retaining particle 100 has a high liquid-retaining performance, which improves the ability of the electrode plate 200 to store the electrolyte 340, and makes the electrode plate 200 have better wetting performance with the electrolyte 340. When the battery 300 is charged and discharged, the active particles in the electrode plate 200 can effectively contact the electrolyte 340. The active ions in the electrolyte 340 can chemically react with the active particles in the active layer 220 and release electrons. The electrode plate 200 has a good liquid-retaining performance, which in turn improves the cycle performance and energy efficiency of the battery 300 when the electrode plate 200 is used in the battery 300.

[0031] It can be understood that, in the terminology of this application, “wetting performance” refers to the ability of the active material in the electrode plate 200 to interact with the electrolyte 340 .

[0032] It can be understood that Figure 4 is an electron microscope image of the electrode plate 200 of an embodiment of the present application. The dotted box A in the figure shows the liquid-retaining particles 100 arranged on the electrode plate 200. The liquid-retaining particles 100 include a core 110 and a shell 120. The shell 120 and the core 110 of the liquid-retaining particles 100 have different colors under the microscope image due to the different materials.

[0033] In some embodiments, the radial dimension d of the capillary pore 122 is in the range of 2 nm ≤ d ≤ 30 nm.

[0034] Specifically, the value of the radial dimension d of the capillary 122 can be, but is not limited to, 2nm, 2.5nm, 3nm, 5nm, 6nm, 8nm, 9nm, 10nm, 12nm, 15nm, 16nm, 18nm, 19nm, 20nm, 22nm, 23nm, 24nm, 25nm, 26nm, 27nm, 28nm, 29nm and 30nm, etc.

[0035] In this embodiment, when the radial dimension d of the capillary pores 122 satisfies the range of 2nm≤d≤30nm, the radial dimension of the capillary pores 122 is within a reasonable range, and the adsorption and storage capacity of the capillary pores 122 for the electrolyte 340 are both within a reasonable range, resulting in a high liquid adsorption capacity per unit particle. When the electrode plate 200 is assembled in the battery 300, the electrode plate 200 has good wettability with the electrolyte 340, which helps to reduce the interfacial impedance between the electrode plate 200 and the electrolyte 340, and thus helps to improve the cycle performance and energy efficiency of the battery 300. In addition, the radial dimension of the capillary pores 122 is prevented from being too large, which would reduce the structural strength of the sub-particles 121, thereby ensuring that the electrode plate 200 has good structural strength. When the radial dimension of the capillary pores 122 is too large, the capillary pores 122 occupy too much space in the sub-particles 121, thereby reducing the structural strength of the sub-particles 121. Since the shell 120 is composed of multiple sub-particles 121, the connection between the sub-particles 121 is also weak, which reduces the structural strength of the shell 120. When the electrode plate 200 is assembled into the battery 300, the liquid-retaining particles 100 with weak structural strength are prone to deformation or breakage during the charge and discharge process of the battery 300, thereby reducing the overall structural strength of the electrode plate 200 and failing to effectively fix and retain the electrolyte 340. This reduces the electrode plate 200's wettability with the electrolyte 340, thereby reducing the cycle performance and energy efficiency of the battery 300. When the radial dimension of the capillary pores 122 is too small, the adsorption and storage capacity of the capillary pores 122 for the electrolyte 340 is reduced, thereby reducing the amount of liquid adsorption per unit particle. When the electrode plate 200 is assembled in the battery 300, the wettability of the electrode plate 200 to the electrolyte 340 decreases, which increases the interfacial impedance of the reaction between the active ions in the electrolyte 340 and the active particles of the electrode plate 200, thereby reducing the cycle performance and energy efficiency of the battery 300.

[0036] Preferably, in some embodiments, the radial dimension d of the capillary pore 122 is in the range of 5 nm ≤ d ≤ 25 nm.

[0037] Specifically, the radial dimension d of the capillary 122 may be, but is not limited to, 5 nm, 6 nm, 8 nm, 9 nm, 10 nm, 12 nm, 15 nm, 16 nm, 18 nm, 19 nm, 20 nm, 22 nm, 23 nm, 24 nm, and 25 nm.

[0038] In some embodiments, in the housing 120, the distribution density a of the capillary pores 122 is in the range of: 0.4 cm 3 / g≤a≤3cm 3 / g.

[0039] Specifically, the distribution density a of the capillary pores 122 may be, but is not limited to, 0.4 cm 3 / g, 0.6cm 3 / g, 0.8cm 3 / g, 0.9cm 3 / g, 1cm 3 / g, 1.2cm 3 / g, 1.5cm 3 / g, 1.6cm 3 / g, 1.8cm 3 / g, 1.9cm 3 / g, 2cm 3 / g, 2.2cm 3 / g, 2.5cm 3 / g, 2.6cm 3 / g, 2.7cm 3 / g, 2.9cm 3 / g and 3cm 3 / g, etc.

[0040] In this embodiment, when the distribution density a of the capillary pores 122 satisfies the range of 0.4 cm 3 / g≤a≤3cm 3 / g, the distribution density of the capillary pores 122 is within a reasonable range, so that the adsorption capacity and wettability of the liquid-retaining particles 100 to the electrolyte 340 are both within a reasonable range. When the electrode plate 200 is assembled in the battery 300, the electrode plate 200 has good wettability to the electrolyte 340, effectively reducing the impedance of the chemical reaction between the active ions in the electrolyte 340 and the active particles of the electrode plate 200, thereby making the battery 300 have higher cycle performance and energy efficiency. In addition, it can avoid the excessive volume of the shell 120 occupied by the capillary pores 122 due to the excessive distribution density of the capillary pores 122, so that the sub-particles 121 and the liquid-retaining particles 100 have better structural strength, and then the overall structural strength of the electrode plate 200 is better. When the distribution density of the capillary pores 122 is too large, the volume occupied by the capillary pores 122 in the shell 120 is too large, which makes the structural strength of the shell 120 weaker. When the electrode plate 200 is assembled in the battery 300, the liquid-retaining particles 100 with relatively weak structural strength are easily deformed or broken during the charge and discharge process of the battery 300, thereby reducing the overall structural strength of the electrode plate 200 and failing to effectively fix and retain the electrolyte 340, reducing the wettability of the electrode plate 200 to the electrolyte 340, thereby reducing the cycle performance and energy efficiency of the battery 300. When the distribution density of the capillary pores 122 is too small, in other words, the volume occupied by all the capillary pores 122 on the shell 120 is too small, thereby making the adsorption and wettability of the liquid-retaining particles 100 to the electrolyte 340 poor, reducing the amount of liquid adsorbed per particle. When the electrode plate 200 is assembled in the battery 300, the wettability of the electrode plate 200 to the electrolyte 340 is poor, thereby reducing the cycle performance and energy efficiency of the battery 300.

[0041] In some embodiments, the particle size D1 of the sub-particles 121 is in the range of 50 nm ≤ D1 ≤ 90 nm.

[0042] Specifically, the particle size D1 of the sub-particle 121 can be, but is not limited to, 50 nm, 55 nm, 58 nm, 60 nm, 64 nm, 68 nm, 70 nm, 72 nm, 75 nm, 78 nm, 80 nm, 82 nm, 84 nm, 86 nm, 88 nm, and 90 nm.

[0043] In this embodiment, when the value of the particle size D1 of the sub-particle 121 satisfies the range of 50nm≤D1≤90nm, the particle size of the sub-particle 121 is within a reasonable range. Accordingly, when the outer diameter of the liquid-retaining particle 100 and the diameter of the inner core 110 are determined, the number of sub-particles 121 of the outer shell 120 is within a reasonable range. When a plurality of sub-particles 121 are spliced ​​into the outer shell 120, the outer shell 120 has a high structural strength. In addition, each of the sub-particles 121 has the capillary pores 122, and the sub-particles 121 can effectively increase the specific surface area of ​​the liquid-retaining particle 100, and the plurality of capillary pores 122 have good adsorption properties for the electrolyte 340, thereby making the liquid-retaining particle 100 have good liquid-retaining ability, which is beneficial to improving the wetting performance of the electrode plate 200 to the electrolyte 340. When the particle size D1 of the sub-particles 121 is too large, the connection between the multiple sub-particles 121 is weakened, making the structural strength of the shell 120 weak, thereby reducing the structural strength of the liquid-retaining particles 100. When the electrode plate 200 is assembled in the battery 300, the liquid-retaining particles 100 with weak structural strength are easily deformed or broken during the charge and discharge process of the battery 300, thereby reducing the overall structural strength of the electrode plate 200 and failing to effectively fix and retain the electrolyte 340, thereby reducing the wettability of the electrode plate 200 to the electrolyte 340, thereby reducing the cycle performance and energy efficiency of the battery 300. When the particle size D1 of the sub-particles 121 is too small, the radial size of the capillary pores 122 of the sub-particles 121 is accordingly too small, making it difficult for the capillary pores 122 to adsorb the electrolyte 340, thereby reducing the liquid retention effect of the liquid-retaining particles 100. When the electrode plate 200 is assembled in the battery 300 , the electrode plate 200 has poor wettability to the electrolyte 340 , which increases the interface impedance between the electrode plate 200 and the electrolyte 340 , thereby causing the battery 300 to have poor cycle performance and low energy efficiency.

[0044] In some embodiments, the diameter of the inner core 110 is D2, and the outer diameter of the liquid-retaining particle 100 is D3, and the relationship is satisfied: 1:3≤D2:D3≤1:1.2.

[0045] Specifically, the value of D2:D3 can be, but is not limited to, 1:3, 1:2.9, 1:2.7, 1:2.5, 1:2.4, 1:2.2, 1:2.0, 1:1.8, 1:1.7, 1:1.6, 1:1.5, 1:1.4, 1:1.3 and 1:12, etc.

[0046] In this embodiment, when the ratio of the diameter D2 of the core 110 to the outer diameter D3 of the liquid-retaining particles 100 satisfies the range of 1:3≤D2:D3≤1:1.2, the diameter D2 of the core 110 and the outer diameter D3 of the liquid-retaining particles 100 are both within a reasonable range. In other words, the diameter of the core 110 and the thickness of the shell 120 are both within a reasonable range. The capillaries 122 of the shell 120 can effectively adsorb the electrolyte 340, and the core 110 has a sufficiently large volume to effectively store the electrolyte 340, resulting in a high liquid adsorption capacity per unit particle. When the electrode plate 200 is assembled in the battery 300, the electrode plate 200 has good wettability with the electrolyte 340, reducing the impedance of the reaction between the active ions in the electrolyte 340 and the active particles of the electrode plate 200, so that the battery 300 has high cycle performance and energy efficiency. When the ratio D2:D3 is too large, the diameter D2 of the core 110 is too large, or the outer diameter D3 of the liquid-retaining particle 100 is too small. In other words, in the liquid-retaining particle 100, the diameter of the core 110 is too large, and the thickness of the shell 120 is too small. If the diameter of the core 110 is too large and the thickness of the shell 120 is too small, the shell 120 has fewer pores 122, which reduces the amount of electrolyte 340 adsorbed by the shell 120. This, in turn, reduces the amount of electrolyte 340 stored in the core 110, reducing the amount of liquid adsorption per particle. When the liquid-retaining particle 100 is applied to the electrode sheet 200 and assembled in the battery 300, the electrode sheet 200 has poor wettability with the electrolyte 340, reducing the cycle performance and energy efficiency of the battery 300. When the value of D2:D3 is too small, the diameter D2 of the core 110 is too small, or the outer diameter D3 of the liquid-retaining particle 100 is too large. In other words, in the liquid-retaining particle 100, the diameter of the core 110 is too small, and the thickness of the shell 120 is too large. In the liquid-retaining particle 100 provided in this embodiment, after the capillaries 122 of the shell 120 adsorb the electrolyte 340, the volume of the core 110 is too small, making it difficult to effectively store the electrolyte 340. Subsequently, the electrolyte 340 adsorbed by the capillaries 122 overflows outside the liquid-retaining particle 100, reducing the amount of liquid adsorbed per particle. When the electrode plate 200 is assembled in the battery 300, the wettability of the electrode plate 200 with the electrolyte 340 is poor, which reduces the cycle performance and energy efficiency of the battery 300.

[0047] In some embodiments, the diameter D2 of the core 110 is in the range of 80 nm ≤ D2 ≤ 300 nm.

[0048] Specifically, the diameter D2 of the core 110 may be, but is not limited to, 80 nm, 85 nm, 90 nm, 100 nm, 120 nm, 140 nm, 150 nm, 160 nm, 180 nm, 190 nm, 200 nm, 210 nm, 220 nm, 230 nm, 250 nm, 270 nm, 280 nm, 290 nm, and 300 nm, etc.

[0049] In this embodiment, when the diameter D2 of the core 110 satisfies the range of 80nm≤D2≤300nm, the value of the diameter D2 of the core 110 is within a reasonable range. To ensure the liquid-retaining effect of the liquid-retaining particles 100, the thickness of the shell 120 is also within a reasonable range. When the capillaries 122 of the shell 120 adsorb the electrolyte 340, the electrolyte 340 can be effectively stored in the core 110, greatly improving the liquid-retaining performance of the liquid-retaining particles 100. When the electrode plate 200 is assembled in the battery 300, the electrode plate 200 has a high wettability for the electrolyte 340, and the battery 300 has good cycle performance. In addition, it can also avoid the difficulty of increasing the compaction of the electrode plate 200 due to the excessively large particle size of the liquid-retaining particles 100. When the electrode plate 200 is used in the battery 300, it has a high compaction density and energy density. When the diameter of the core 110 is too large, the shell 120 must be thick enough to ensure the liquid-retaining effect of the liquid-retaining particles 100, resulting in an excessively large outer diameter of the liquid-retaining particles 100. In other words, the particle size of the liquid-retaining particles 100 is too large. When the liquid-retaining particles 100 are applied to the electrode plate 200, a large gap exists between the liquid-retaining particles 100 with an excessively large particle size and the active particles, resulting in a low compaction density of the electrode plate 200 and a reduction in the energy density of the electrode plate 200. When the diameter of the core 110 is too small, after the shell 120 adsorbs the electrolyte 340, the core 110 is insufficient to store the electrolyte 340, causing the electrolyte 340 to overflow from the liquid-retaining particles 100, thereby reducing the liquid-retaining performance of the liquid-retaining particles 100. When the liquid-retaining particles 100 are applied to the electrode plate 200 and assembled in the battery 300 , the electrode plate 200 has poor wettability to the electrolyte 340 , resulting in poor cycle performance of the battery 300 .

[0050] In some embodiments, the core 110 is selected from one or more synthetic polymers selected from acrylic acid, acrylic esters, acrylamide, acrylonitrile, butadiene, styrene, and tetrafluoroethylene.

[0051] In this embodiment, the core 110 is a polymer synthesized from monomers selected from one or more polymers selected from acrylic acid, acrylic esters, acrylamide, acrylonitrile, butadiene, styrene, and tetrafluoroethylene. This allows the core 110 to have good adhesion to both the core 110 and the outer shell 120. Furthermore, when the liquid-retaining particles 100 are applied to the electrode sheet 200, the liquid-retaining particles 100 also have good adhesion to the active particles. Furthermore, the material selected for the core 110 has low reactivity. When the liquid-retaining particles 100 are applied to the electrode sheet 200 and assembled into the battery 300, side reactions between the liquid-retaining particles 100 and the active particles or the electrolyte 340 are avoided, thereby ensuring the liquid-retaining properties of the liquid-retaining particles 100. This, in turn, improves the wettability of the electrode sheet 200 with the electrolyte 340, thereby enhancing the cycle performance and energy efficiency of the battery 300.

[0052] Optionally, the core 110 is selected from one of styrene-butadiene rubber (SBR), polyacrylic acid (PAA), polyacrylonitrile (PAN) and polyvinylidene fluoride (PVDF).

[0053] In some embodiments, the shell 120 is selected from one of silane, silicon dioxide, silicate, and aluminum oxide.

[0054] It can be understood that the material selected for the shell 120 is an inorganic material.

[0055] In this embodiment, the shell 120 is selected from one of silanes, silica, silicates, and aluminum oxide. Compared to the shell 120 selected from polymers with poor oxidation properties such as styrene-butadiene rubber, silanes, silica, silicates, and aluminum oxide do not contain double bonds, which makes the shell 120 have higher antioxidant properties. When the liquid-retaining particles 100 are applied to the electrode plate 200 and the electrode plate 200 is the positive electrode plate 310, the liquid-retaining particles 100 are not easily oxidized under the action of high voltage. Therefore, the liquid-retaining particles 100 provided in this application can be applied to both the negative electrode plate 330 and the positive electrode plate 310, thereby enhancing the applicability of the liquid-retaining particles 100.

[0056] Optionally, in some embodiments, the capillaries 122 of the sub-particles 121 of the shell 120 are prepared by mixing one of silanes, silica, silicates, and alumina with a pore-forming agent, so that the resulting shell 120 has a plurality of sub-particles 121, and then volatilizing the pore-forming agent by means of high temperature or the like, to obtain the capillaries 122 of the sub-particles 121. Specifically, one of silanes, silica, silicates, and alumina is placed in an organic solution (e.g., alkyl esters, cyclohexane), and added to an aqueous solution containing an alkylammonium cationic emulsifier, heated and stirred to allow the reaction to proceed. Through a two-phase method, one of silanes, silica, silicates, and alumina can be continuously precipitated and transferred to the aqueous phase. Finally, the organic solution remaining on the surface of the sub-particles 121 is removed by high-temperature drying, thereby forming the sub-particles 121 with the capillaries 122.

[0057] In some embodiments, the specific surface area of ​​the liquid-retaining particles 100 is in the range of 85 m 2 / g to 350m 2 / g.

[0058] Specifically, the specific surface area of ​​the liquid-retaining particles 100 may be, but is not limited to, 85 m 2 / g、88m 2 / g、100m 2 / g, 120m 2 / g、125m 2 / g, 150m 2 / g、155m 2 / g、188m 2 / g, 190m 2 / g, 200m 2 / g、205m 2 / g, 235m 2 / g, 250m 2 / g, 265m 2 / g, 280m 2 / g、295m 2 / g、300m 2 / g、310m 2 / g、325m 2 / g、335m 2 / g and 350m 2 / g, etc.

[0059] In this embodiment, when the specific surface area of ​​the liquid-retaining particles 100 meets the range of 85m 2 / g to 350m 2 / g, the specific surface area of ​​the liquid-retaining particles 100 is within a reasonable range. It can be understood that the capillaries 122 of the sub-particles 121 greatly increase the specific surface area of ​​the liquid-retaining particles 100, thereby increasing the contact area between the liquid-retaining particles 100 and the electrolyte 340. After the capillaries 122 of the liquid-retaining particles 100 absorb the electrolyte 340, the electrolyte 340 can be stored in the core 110, and the liquid-retaining particles 100 have strong liquid retention properties. When the liquid-retaining particles 100 are applied to the electrode plate 200 and assembled into the battery 300, the electrode plate 200 has good wettability with the electrolyte 340, thereby enabling the battery 300 to have good cycle performance and high energy efficiency. When the specific surface area of ​​the liquid-retaining particles 100 is too large, the capillaries 122 occupy a correspondingly large area on the surface of the shell 120, which weakens the structural strength of the shell 120. When the liquid-retaining particles 100 are applied to the electrode plate 200 and assembled in the battery 300, the liquid-retaining particles 100, which have a relatively weak structural strength, are easily deformed or broken during the charge and discharge process of the battery 300, thereby reducing the overall structural strength of the electrode plate 200 and failing to effectively fix and retain the electrolyte 340. This reduces the wettability of the electrode plate 200 with the electrolyte 340, thereby reducing the cycle performance and energy efficiency of the battery 300. When the specific surface area of ​​the liquid-retaining particles 100 is too small, the capillary pores 122 on the surface of the shell 120 occupy a relatively small area, which in turn reduces the effective contact area between the liquid-retaining particles 100 and the electrolyte 340, reducing the adsorption capacity and wettability of the liquid-retaining particles 100 with the electrolyte 340, and reducing the amount of liquid adsorbed per particle. When the liquid-retaining particles 100 are applied to the electrode plate 200 and assembled in the battery 300 , the electrode plate 200 has poor wettability to the electrolyte 340 , thereby reducing the cycle performance and energy efficiency of the battery 300 .

[0060] Please refer to Figure 5. The present application provides a battery 300, which includes: a positive electrode sheet 310, a diaphragm 320, a negative electrode sheet 330 and an electrolyte 340. The diaphragm 320 is arranged on one side of the positive electrode sheet 310; the negative electrode sheet 330 is arranged on the side of the diaphragm 320 away from the positive electrode sheet 310, and at least one of the positive electrode sheet 310 and the negative electrode sheet 330 is the electrode sheet 200 provided in the present application; the electrolyte 340 at least soaks part of the positive electrode sheet 310 and part of the negative electrode sheet 330.

[0061] It can be understood that the positive electrode sheet 310 , the separator 320 and the negative electrode sheet 330 are stacked in sequence.

[0062] It can be understood that in this embodiment, the positive electrode plate 310 is the electrode plate 200 provided in this application; in other embodiments, the negative electrode plate 330 is the electrode plate 200 provided in this application; in some other embodiments, the positive electrode plate 310 and the negative electrode plate 330 are both the electrode plate 200 provided in this application.

[0063] In this embodiment, when at least one of the positive electrode plate 310 and the negative electrode plate 330 is the electrode plate 200 provided in this application, the electrode plate 200 has good wettability to the electrolyte 340, which is beneficial to reducing the impedance of the reaction between the active ions in the electrolyte 340 and the active particles in the electrode plate 200, so that the battery 300 has better cycle performance and higher energy efficiency.

[0064] Optionally, the battery 300 may be, but is not limited to, a lithium-ion battery, a sodium-ion battery, or the like.

[0065] Optionally, the battery 300 may be a cylindrical battery, a square battery, a soft-pack battery, or the like.

[0066] Optionally, the material of the diaphragm 320 is selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, and polyvinylidene fluoride. In some embodiments, the diaphragm 320 is a single-layer film; in other embodiments, the diaphragm 320 is a multi-layer composite film. When the diaphragm 320 is a multi-layer composite film, the materials of each layer can be the same or different.

[0067] Optionally, the thickness of the diaphragm 320 ranges from 14 μm to 18 μm. Specifically, the thickness of the diaphragm 320 may be, but is not limited to, 14 μm, 14.5 μm, 15 μm, 15.5 μm, 16 μm, 16.5 μm, 17 μm, 17.5 μm, and 18 μm.

[0068] Optionally, the current collector layer 210 of the positive electrode plate 310 is selected from aluminum foil. The current collector layer 210 of the positive electrode plate 310 has good electrical conductivity and high mechanical strength.

[0069] Optionally, the active layer 220 of the positive electrode plate 310 includes active particles, and the active particles of the positive electrode plate 310 are selected from lithium transition metal oxide particles and modified particles thereof, wherein the modified particles refer to lithium transition metal oxides that are doped and / or coated.

[0070] Preferably, the active particles of the positive electrode plate 310 are selected from one or more of lithium cobalt oxide, lithium nickel oxide, lithium manganese oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide, and lithium nickel cobalt aluminum oxide.

[0071] Optionally, the active layer 220 of the positive electrode sheet 310 further includes a positive electrode binder and a positive electrode conductive agent. The positive electrode binder is used to bind the components in the active layer 220 (e.g., at least two of the active particles, the positive electrode conductive agent, and the liquid-retaining particles 100) to improve the overall performance of the positive electrode sheet 310. The positive electrode conductive agent is used to improve the electrical conductivity of the active layer 220.

[0072] Optionally, the positive electrode binder is selected from at least one of polyvinylidene fluoride and polytetrafluoroethylene.

[0073] Optionally, the positive electrode conductive agent is selected from at least one of graphite, superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene and carbon nanofibers.

[0074] Optionally, the current collector layer 210 of the negative electrode plate 330 is selected from copper foil. The current collector layer 210 of the negative electrode plate 330 has good electrical conductivity and high mechanical strength.

[0075] Optionally, the active particles of the negative electrode plate 330 are selected from one or more of graphite, mesophase microcarbon beads, hard carbon and soft carbon, preferably graphite. The graphite can be selected from one or more of artificial graphite and natural graphite.

[0076] Optionally, the active layer 220 of the negative electrode sheet 330 further includes a negative electrode binder, a negative electrode conductive agent, and a thickener. The negative electrode binder is used to bind the components of the active layer 220 (e.g., at least two of the active particles, the negative electrode conductive agent, the liquid-retaining particles 100, and the thickener) to improve the overall performance of the negative electrode sheet 330. The negative electrode conductive agent is used to improve the conductivity of the active layer 220 of the negative electrode sheet 330. The thickener is used to improve the adhesion of the active layer 220 of the negative electrode sheet 330.

[0077] Optionally, the negative electrode conductive agent is selected from at least one of acetylene black, conductive carbon black, carbon nanotubes, carbon fibers, graphene, and the like.

[0078] Optionally, the negative electrode binder is selected from one or more of polyacrylic acid (PAA), sodium polyacrylate (PAAS), polyvinyl alcohol (PVA), styrene-butadiene rubber (SBR), carboxymethyl cellulose (CMC), sodium alginate, polymethacrylate (PMA) and carboxymethyl chitosan (CMCS).

[0079] Optionally, the thickener is selected from at least one of sodium carboxymethyl cellulose (CMC), polyacrylamide (PAM) and polymethacrylate (PMA).

[0080] Optionally, the electrolyte 340 includes an electrolyte salt and a solvent, and the solvent is used to dissolve the electrolyte salt so that the electrolyte salt releases active ions.

[0081] Optionally, the electrolyte salt is selected from one or more of lithium hexafluorophosphate (LiPF6), lithium tetrafluoroborate (LiBF4), lithium perchlorate (LiClO4), lithium hexafluoroarsenate (LiAsF6), lithium bis(fluorosulfonyl)imide (LiFSI), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), lithium trifluoromethanesulfonate (LiTFS), lithium difluorooxalatoborate (LiDFOB), lithium dioxalatoborate (LiBOB), lithium difluorophosphate (LiPO2F2), lithium difluorobis(oxalatophosphate) (LiDFOP) and lithium tetrafluorooxalatophosphate (LiTFOP).

[0082] Optionally, the solvent is selected from one or more of ethylene carbonate (EC), propylene carbonate (PC), ethyl methyl carbonate (EMC), diethyl carbonate (DEC), dimethyl carbonate (DMC), dipropyl carbonate (DPC), methyl propyl carbonate (MPC), ethyl propyl carbonate (EPC), butylene carbonate (BC), fluoroethylene carbonate (FEC), methyl formate (MF), methyl acetate (MA), ethyl acetate (EA), propyl acetate (PA), methyl propionate (MP), ethyl propionate (EP), propyl propionate (PP), methyl butyrate (MB), ethyl butyrate (EB), 1,4-butyrolactone (GBL), sulfolane (SF), dimethyl sulfone (MSM), ethyl methyl sulfone (EMS) and diethyl sulfone (ESE).

[0083] Optionally, the electrolyte 340 further includes an additive, which is dissolved in the solvent. The additive may be, but is not limited to, a positive electrode film-forming additive or a negative electrode film-forming additive. The additive may also be an additive that improves the performance of the battery 300. Optionally, the additive may be an additive that improves the overcharge performance of the battery 300, an additive that improves the high-temperature performance of the battery 300, or an additive that improves the low-temperature performance of the battery 300.

[0084] In some embodiments, the positive electrode plate 310 is the electrode plate 200 provided in the present application. In the active layer 220 of the positive electrode plate 310 , the mass fraction A1 of the liquid-retaining particles 100 is in the range of 0.4%≤A1≤1.2%.

[0085] Specifically, the mass fraction A1 of the liquid-retaining particles 100 can be, but is not limited to, 0.4%, 0.45%, 0.48%, 0.5%, 0.52%, 0.58%, 0.6%, 0.65%, 0.7%, 0.75%, 0.8%, 0.9%, 0.95%, 1%, 1.05%, 1.1%, 1.15% and 1.2%, etc.

[0086] It can be understood that in the active layer 220 of the positive electrode sheet 310 , the mass fraction of the liquid-retaining particles 100 is the ratio of the mass of the liquid-retaining particles 100 to the mass of the active layer 220 of the positive electrode sheet 310 .

[0087] In this embodiment, in the active layer 220 of the positive electrode sheet 310, when the mass fraction A1 of the liquid-retaining particles 100 satisfies the range of 0.4% ≤ A1 ≤ 1.2%, the mass fraction of the liquid-retaining particles 100 is within a reasonable range. On the one hand, the liquid-retaining particles 100 have good liquid-retaining properties, which can effectively improve the wettability of the positive electrode sheet 310 to the electrolyte 340 and reduce the interfacial impedance of the active ions in the electrolyte 340 between the positive electrode sheet 310 and the electrolyte 340, thereby enabling the battery 300 to have good cycle performance. On the other hand, the mass fraction of the active particles in the positive electrode sheet 310 is also within a reasonable range, thereby enabling the positive electrode sheet 310 to have a higher energy density, which is beneficial for extending the cycle life of the battery 300. When the mass fraction of the liquid-retaining particles 100 is too high, the mass fraction of the liquid-retaining particles 100 in the active layer 220 of the positive electrode sheet 310 is too large, resulting in a too small mass fraction of the active particles, which reduces the energy density of the positive electrode sheet 310 and shortens the cycle life of the battery 300 when the positive electrode sheet 310 is used in the battery 300. When the mass fraction of the liquid-retaining particles 100 is too low, the mass fraction of the liquid-retaining particles 100 in the active layer 220 of the positive electrode sheet 310 is too small, making it difficult for the liquid-retaining particles 100 to improve the wettability of the positive electrode sheet 310 with the electrolyte 340. When the positive electrode sheet 310 is used in the battery 300, the active ions in the electrolyte 340 have too high an impedance at the interface between the electrolyte 340 and the positive electrode sheet 310, resulting in poor cycle performance and low energy efficiency of the battery 300.

[0088] In some embodiments, the negative electrode plate 330 is the electrode plate 200 provided in this application. In the active layer 220 of the negative electrode plate 330 , the mass fraction A2 of the liquid-retaining particles 100 is in the range of 0.2%≤A2≤0.8%.

[0089] Specifically, the mass fraction A2 of the liquid-retaining particles 100 can be, but is not limited to, 0.2%, 0.25%, 0.3%, 0.35%, 0.4%, 0.45%, 0.48%, 0.5%, 0.52%, 0.55%, 0.6%, 0.65%, 0.7%, 0.75% and 0.8%, etc.

[0090] It can be understood that the mass fraction of the liquid-retaining particles 100 in the active layer 220 of the negative electrode plate 330 is the ratio of the mass of the liquid-retaining particles 100 to the mass of the active layer 220 of the negative electrode plate 330 .

[0091] In this embodiment, in the active layer 220 of the negative electrode plate 330, when the mass fraction A1 of the liquid-retaining particles 100 satisfies the range of 0.2% ≤ A2 ≤ 0.8%, the mass fraction of the liquid-retaining particles 100 is within a reasonable range. On the one hand, the liquid-retaining particles 100 have excellent liquid retention properties, effectively improving the wettability of the negative electrode plate 330 with the electrolyte 340 and reducing the interfacial impedance of the active ions in the electrolyte 340 between the negative electrode plate 330 and the electrolyte 340, thereby enabling the battery 300 to have good cycle performance. On the other hand, the mass fraction of the active particles in the negative electrode plate 330 is also within a reasonable range, thereby enabling the negative electrode plate 330 to have a high energy density, which is beneficial for extending the cycle life of the battery 300. When the mass fraction of the liquid-retaining particles 100 is too high, the mass fraction of the liquid-retaining particles 100 in the active layer 220 of the negative electrode plate 330 becomes too large, resulting in a smaller mass fraction of the active particles. This reduces the energy density of the negative electrode plate 330 and shortens the cycle life of the battery 300 when the negative electrode plate 330 is used. Furthermore, further increasing the mass fraction of the liquid-retaining particles 100 makes it difficult to further improve the liquid retention performance of the negative electrode plate 330, which in turn increases the raw material cost of the negative electrode plate 330. When the mass fraction of the liquid-retaining particles 100 is too low, the mass fraction of the liquid-retaining particles 100 in the active layer 220 of the negative electrode plate 330 becomes too small, making it difficult for the liquid-retaining particles 100 to improve the wettability of the negative electrode plate 330 with the electrolyte 340. When the negative electrode plate 330 is applied to the battery 300 , the impedance of the active ions in the electrolyte 340 at the interface between the electrolyte 340 and the negative electrode plate 330 is too large, resulting in poor cycle performance and low energy efficiency of the battery 300 .

[0092] The technical solution of this application is further described below with reference to a number of embodiments.

[0093] Examples 1 to 8, Comparative Examples

[0094] 1. Preparation of liquid-retaining granules 100:

[0095] First, the sub-particles 121 are formed. Specifically, one of silanes, silica, silicates, and aluminum oxides is placed in an organic solution (e.g., alkyl esters, cyclohexane), wherein the organic solvent acts as a pore-forming agent, and is added to an aqueous solution containing an alkylammonium cationic emulsifier. The solution is heated and stirred to allow the reaction to proceed. Through a two-phase method, one of silanes, silica, silicates, and aluminum oxides can be continuously precipitated and transferred to the aqueous phase. Finally, the organic solution remaining on the surface of the sub-particles 121 is removed by high-temperature drying, thereby forming sub-particles 121 with capillary pores 122. The radial dimension d of the capillary pores 122 is in the range of 2nm≤d≤30nm; the distribution density a of the capillary pores 122 is in the range of 0.4cm 3 / g≤a≤3cm 3 The radial dimension d of the capillary pores 122 and the distribution density a of the capillary pores 122 can be controlled by adjusting the type of organic solvent, the solubility of the organic solvent in one of silanes, silica, silicates, and alumina, and the concentration of the organic solvent in one of silanes, silica, silicates, and alumina.

[0096] Furthermore, a polymer synthesized from one or more of acrylic acid, acrylic esters, acrylamide, acrylonitrile, butadiene, styrene, and tetrafluoroethylene is used as the material of the core 110, and the sub-particles 121 are mixed, stirred, and adsorbed with the material of the core 110 to obtain the liquid-retaining particles 100. The ratio of the core 110 to the liquid-retaining particles D3 is controlled by the mass ratio of the sub-particles 121 to the material of the core 110.

[0097] 2. Preparation of electrode plate 200:

[0098] (1) Preparation of positive electrode sheet 310:

[0099] Active particles, liquid-retaining particles 100, a positive electrode conductive agent, and a positive electrode binder suitable for the active layer 220 of the positive electrode sheet 310 are dispersed in a solvent (e.g., N-methylpyrrolidone) to form a uniform positive electrode slurry. The positive electrode slurry is then coated on the current collector layer 210 to form the active layer 220 of the positive electrode sheet 310. After drying and cold pressing, the positive electrode sheet 310 is obtained. The mass fraction A1 of the liquid-retaining particles 100 in the active layer 220 of the positive electrode sheets 310 of Examples 1 to 8 and the comparative example is shown in Table 1.

[0100] (2) Preparation of negative electrode sheet 330:

[0101] Active particles, liquid-retaining particles 100, a negative electrode conductive agent, a negative electrode binder, and a thickener suitable for the active layer 220 of the negative electrode sheet 330 are dispersed in a solvent (e.g., deionized water) to form a uniform negative electrode slurry. The negative electrode slurry is then coated on a negative electrode current collector to form the active layer 220 of the negative electrode sheet 330. After drying and cold pressing, the negative electrode sheet 330 is obtained. The mass fraction A2 of the liquid-retaining particles 100 in the active layer 220 of the negative electrode sheets 330 of Examples 1 to 8 and the comparative example is shown in Table 1.

[0102] 3. Preparation of diaphragm 320 and electrolyte 340:

[0103] A polyethylene separator 320 with a thickness of 16 μm was selected.

[0104] In an argon atmosphere glove box with a moisture content of ≤1 ppm, ethylene carbonate, dimethyl carbonate, and ethyl methyl carbonate are mixed in a mass ratio of 1:1:1. Then, a dry electrolyte salt (e.g., lithium hexafluorophosphate) is dissolved in a solvent and stirred until completely dissolved. An additive is added and mixed uniformly to obtain an electrolyte solution 340.

[0105] 4. Assembly of Battery 300:

[0106] The positive electrode sheets 310 and separators 320 of Examples 1 to 8 and the comparative example, as well as the negative electrode sheets 330 of Examples 1 to 8 and the comparative example prepared above are stacked in sequence, with the separator 320 located between the positive electrode sheet 310 and the negative electrode sheet 330, and then wound to obtain a bare cell. The bare cell is placed in an outer package, and after drying, the above-mentioned electrolyte 340 is injected. After standing, forming, and packaging, the implementation battery 1 to the implementation battery 8 and the comparative battery are obtained, wherein the positive electrode sheet 310 of Example 1 and the negative electrode sheet 330 of Example 1 are arranged in the implementation battery 1, the positive electrode sheet 310 of Example 2 and the negative electrode sheet 330 of Example 2 are arranged in the implementation battery 2, the positive electrode sheet 310 of the comparative battery and the positive electrode sheet 310 of the comparative battery are arranged in the comparative battery, and so on.

[0107] Table 1 below shows the structural parameters of the positive electrode sheets 310 and the negative electrode sheets 330 of Examples 1 to 8 and the comparative example. Table 1 shows the mass fraction A1 of the liquid-retaining particles 100 in the active layer 220 of the positive electrode sheets 310 and the mass fraction A2 of the liquid-retaining particles 100 in the active layer 220 of the negative electrode sheets 330 of Examples 1 to 8 and the comparative example.

[0108] Table 1: Structural parameters of the positive electrode sheet 310 and the negative electrode sheet 330 of Examples 1 to 8 and the comparative example.

[0109] Battery 300 performance test

[0110] 1. Testing of the wettability of the electrode plate 200 to the electrolyte 340:

[0111] At 25°C, the electrode plates 200 prepared in Examples 1 to 8 and the comparative example were cut into samples with a fixed length of 14 cm and a fixed width of 1.5 cm and horizontally stretched. 2 mL of electrolyte 340 was injected with a syringe and dropped onto the electrode plates 200. After 3 minutes, the infiltration length of the electrode plates 200 was measured.

[0112] The electrode sheet 200 includes a positive electrode sheet 310 and a negative electrode sheet 330. The values ​​of the infiltration length of the positive electrode sheet 310 and the infiltration length of the negative electrode sheet 330 in the electrolyte 340 in the battery 1 to the battery 8 and the comparative example are shown in Table 2.

[0113] 2. Battery 300 internal resistance performance test:

[0114] (1) Calculation of DCR (Direct Current Internal Resistance) at 50% SOC (State of Charge):

[0115] The test temperature is 25°C. After formation, implementation batteries 1 to implementation batteries 8 and the comparison battery are charged at a constant current of 0.5C to 3.65V, then charged at a constant voltage of 3.65V to a current of 0.05C, and allowed to stand for 10 minutes; then discharged at a constant current of 0.5C to 2.5V, and allowed to stand for 10 minutes. The capacity of this step is recorded as C0. Under 25°C conditions, the implementation batteries 1 to implementation batteries 8 and the comparison battery are charged at a constant current of 1C for 30 minutes. At this time, the implementation batteries 1 to implementation batteries 8 and the comparison battery are in a charging state of 50% SOC. They are allowed to stand for 1 hour, discharged at 1.07C0 for 30 seconds, allowed to stand for 40 seconds, and V1 is recorded. They are charged at 1.07C0 for 30s, and V2 is recorded. After standing for 10 minutes, the DC resistance DCR corresponding to the implementation batteries 1 to implementation batteries 8 and the comparison battery at the charging state of 50% SOC is calculated as DCR = (V2-V1) / 1.07C0.

[0116] (2) Calculation of 50% SOC discharge DCR:

[0117] The test temperature was 25°C. After formation, batteries 1 to 8 and the comparative battery were charged at a constant current of 0.5C0 to 3.65V, then charged at a constant voltage of 3.65V to a current of 0.05C, and allowed to stand for 10 minutes. They were discharged at a constant current of 1C for 30 minutes, at which point batteries 1 to 8 and the comparative battery were at a 50% SOC discharge state. They were allowed to stand for 1 hour, and V3 was recorded. They were then discharged at 1.07C0 for 30 seconds, allowed to stand for 40 seconds, and V4 was recorded. After standing for 10 minutes, the DC resistance DCR' corresponding to the 50% discharge state of batteries 1 to 8 and the comparative battery was calculated as (V3-V4) / 1.07C0.

[0118] The 50% SOC discharge DCR refers to the DC internal resistance measured when the battery 300 is discharged at 50% remaining capacity. The 50% SOC charge DCR refers to the DC internal resistance measured when the battery 300 is charged at 50% remaining capacity. The 50% SOC discharge DCR and 50% SOC charge DCR values ​​for Example Batteries 1 to 8 and the comparative battery are shown in Table 2.

[0119] 3. Battery 300 cycle performance test:

[0120] Batteries 1 to 8 and the comparative battery were left to stand at 25°C for 1 hour, charged to 3.65V at 0.5P, and then discharged to 2.5V at 0.5P. The initial discharge capacity C1 of the battery 300 was recorded, and the initial discharge energy was E1. Batteries 1 to 8 and the comparative battery were cycled for 3 cycles, and the discharge energy E3 and the charge energy E'3 were recorded. The energy efficiency of batteries 1 to 8 and the comparative battery after 3 cycles was obtained as E=E3 / E'3×100%. Batteries 1 to 8 and the comparative battery were cycled for 1 cycle, and the initial discharge capacity C1 of the battery 300 was recorded. Batteries 1 to 8 and the comparative battery were cycled for 200 cycles, and the discharge capacity C 200 , the capacity retention rate Cf=C of the implementation battery 1 to the implementation battery 8 and the comparison battery after 200 cycles 200 / C1×100%.

[0121] The energy efficiency E and capacity retention rate Cf of the implementation batteries 1 to 8 and the comparison battery after 500 cycles are shown in Table 2.

[0122] Table 2 below shows the performance parameters of implementation batteries 1 to 8 and comparison batteries.

[0123] Table 2: Performance parameters of implementation batteries 1 to 8 and comparative batteries.

[0124] Referring to Tables 1 and 2, neither the positive electrode sheet 310 nor the negative electrode sheet 330 in Comparative Example 1 includes the liquid-retaining particles 100. At 25°C, the infiltration length of the positive electrode sheet 310 into the electrolyte 340 is 1.2 cm, and the infiltration length of the negative electrode sheet 330 into the electrolyte 340 is 2.5 cm. The infiltration length of the electrode sheet 200 into the electrolyte 340 can indicate the infiltration performance of the electrode sheet 200 into the electrolyte 340. Specifically, the greater the infiltration length of the positive electrode sheet 310 into the electrolyte 340, the better the infiltration performance of the positive electrode sheet 310 into the electrolyte 340; and the greater the infiltration length of the negative electrode sheet 330 into the electrolyte 340, the better the infiltration performance of the negative electrode sheet 330 into the electrolyte 340.

[0125] Referring to Examples 1 to 5 and the comparative example, the mass fraction A1 of the liquid-retaining particles 100 in the active layer 220 of the positive electrode sheet 310 in Examples 1 to 5 is 0. In other words, the active layer 220 of the positive electrode sheet 310 in Examples 1 to 5 does not include liquid-retaining particles 100. The mass fraction A2 of the liquid-retaining particles 100 in the active layer 220 of the negative electrode sheet 330 in Examples 1 to 4 satisfies the range of 0.2% ≤ A2 ≤ 0.8%. In Example 5, the mass fraction A2 of the liquid-retaining particles 100 in the active layer 220 of the negative electrode sheet 330 is greater than 0.8. From the performance parameters of the implementation batteries 1 to 5, it can be seen that the infiltration length of the negative electrode sheet 330 to the electrolyte 340 in the implementation batteries 1 to 5 is greater than the infiltration length of the negative electrode sheet 330 to the electrolyte 340 in the comparison battery. The values ​​of the 50% SOC discharge DCR and the 50% SOC charge DCR in the implementation batteries 1 to 5 are respectively smaller than the values ​​of the 50% SOC discharge DCR and the 50% SOC charge DCR in the comparison battery. In addition, the energy efficiency of the three cycles of the implementation batteries 1 to 5 and The cycle capacity retention rate after 200 cycles is higher than the cycle energy efficiency and cycle capacity retention rate after 3 cycles in the control battery, respectively. This is because: the negative electrode plates 330 in Examples 1 to 5 all include liquid-retaining particles 100, and the liquid-retaining particles 100 include a core 110 and a shell 120. The shell 120 has a plurality of capillaries 122, each of which can be used to absorb electrolyte 340 and store the electrolyte 340 in the core 110. The liquid-retaining particles 100 have good liquid retention performance. When the liquid-retaining particles 100 are applied to the negative electrode plate 330, the wettability of the negative electrode plate 330 to the electrolyte 340 is improved, thereby increasing the wettability of the negative electrode plate 330 to the electrolyte 340. In addition, the better the wetting performance of the negative electrode plate 330 to the electrolyte 340, the larger the effective contact area between the electrolyte 340 and the negative electrode plate 330, which reduces the interfacial impedance of the active ions in the battery 300 at the negative electrode plate 330 and the electrolyte 340, thereby making the 50% SOC discharge DCR value of the implementation battery 1 to the implementation battery 5 smaller than the 50% SOC discharge DCR value of the comparison battery, and the 50% SOC charging DCR value of the implementation battery 1 to the implementation battery 5 smaller than the 50% SOC charging DCR value of the comparison battery, which is more conducive to the charge and discharge process of the battery 300, and ultimately makes the cycle energy efficiency and capacity retention rate of the implementation battery 1 to the implementation battery 5 higher, and the implementation battery 1 to the implementation battery 5 have better cycle performance than the comparison battery.Furthermore, as the mass fraction of the liquid-retaining particles 100 in the active layer 220 of the negative electrode sheet 330 continues to increase, the wetting length of the negative electrode sheet 330 to the electrolyte 340 continues to increase. When the value of A2 is greater than 0.8%, it is difficult to increase the wetting length of the negative electrode sheet 330 to the electrolyte 340 by continuing to increase the liquid-retaining particles 100. Therefore, in order to save the raw material cost of the negative electrode sheet 330, the use of too many liquid-retaining particles 100 should be avoided. When A2 satisfies the range of 0.2%≤A2≤0.8%, the negative electrode sheet 330 can have a higher wetting performance to the electrolyte 340 and the raw material cost of the negative electrode sheet 330 can also be effectively controlled.

[0126] Referring to Examples 6 and 7 and the comparative example, the mass fraction A1 of the liquid-retaining particles 100 in the active layer 220 of the negative electrode sheet 330 in Examples 6 and 7 is 0. In other words, the active layer 220 of the negative electrode sheet 330 in Examples 6 and 7 does not include liquid-retaining particles 100. The mass fraction A1 of the liquid-retaining particles 100 in the active layer 220 of the positive electrode sheet 310 in Examples 6 and 7 satisfies the range of 0.4% ≤ A1 ≤ 1.2%. From the performance parameters of the implementation battery 6 and the implementation battery 7, it can be seen that the infiltration length of the positive electrode plate 310 to the electrolyte 340 in the implementation battery 6 to the implementation battery 7 is greater than the infiltration length of the positive electrode plate 310 to the electrolyte 340 in the comparison battery. The 50% SOC discharge DCR value and the 50% SOC charge DCR value of the implementation battery 6 and the implementation battery 7 are respectively smaller than the 50% SOC discharge DCR value and the 50% SOC charge DCR value of the comparison battery. In addition, the cycle energy efficiency and The cycle capacity retention rate after 200 cycles is higher than the cycle energy efficiency and cycle capacity retention rate after 3 cycles in the control battery, respectively. This is because: the positive electrode sheets 310 in Examples 6 and 7 both include liquid-retaining particles 100, and the liquid-retaining particles 100 include a core 110 and a shell 120. The shell 120 has a plurality of capillaries 122, each of which can be used to absorb the electrolyte 340 and store the electrolyte 340 in the core 110. The liquid-retaining particles 100 have good liquid retention performance. When the liquid-retaining particles 100 are applied to the positive electrode sheet 310, the wettability of the positive electrode sheet 310 to the electrolyte 340 is improved, thereby increasing the wettability of the positive electrode sheet 310 to the electrolyte 340. In addition, the better the wettability of the positive electrode sheet 310 to the electrolyte 340, the larger the effective contact area between the electrolyte 340 and the positive electrode sheet 310, which reduces the interfacial impedance of the active ions in the battery 300 at the positive electrode sheet 310 and the electrolyte 340, thereby making the 50% SOC discharge DCR value of the implementation battery 6 and the implementation battery 7 smaller than the 50% SOC discharge DCR value of the comparison battery, and the 50% SOC charging DCR value of the implementation battery 6 and the implementation battery 7 smaller than the 50% SOC charging DCR value of the comparison battery, which is more conducive to the charge and discharge process of the battery 300, and ultimately makes the cycle energy efficiency and capacity retention rate of the implementation battery 6 and the implementation battery 7 higher, and the implementation battery 6 and the implementation battery 7 have better cycle performance than the comparison battery.

[0127] Further, please refer to Example 7 and Example 8. In Example 8, the positive electrode plate 310 and the negative electrode plate 330 both include liquid-retaining particles 100. Compared with the embodiment in which one of the positive electrode plate 310 and the negative electrode plate 330 is the electrode plate 200 provided in the application, the implementation battery 8 has lower 50% SOC discharge DCR and 50% SOC charging DCR than the implementation battery 7, and the implementation battery 8 has higher cycle energy efficiency for 3 cycles and cycle capacity retention rate for 200 cycles than the implementation battery 7. This is because: in the implementation of battery 8, both the positive electrode sheet 310 and the negative electrode sheet 330 include liquid-retaining particles 100, and the mass fraction A1 of the liquid-retaining particles 100 in the active layer 220 of the positive electrode sheet 310 and the mass fraction A2 of the liquid-retaining particles 100 in the active layer 220 of the negative electrode sheet 330 are both within a reasonable range. The liquid-retaining particles 100 have good liquid-retaining performance, which in turn makes the positive electrode sheet 310 and the negative electrode sheet 330 have good wetting performance with the electrolyte 340, greatly reducing the interface impedance of the active ions in the battery 300 between the positive electrode sheet 310 and the electrolyte 340 and the interface impedance between the negative electrode sheet 330 and the electrolyte 340, so that the implementation of battery 8 has higher cycle performance and energy efficiency.

[0128] Please refer to Figures 6 and 7. The present application provides an electric device 400, which includes: a device body 410 and a battery 300 provided in the present application, and the battery 300 supplies power to the device body 410.

[0129] It can be understood that the battery 300 is electrically connected to the device body 410 .

[0130] In this embodiment, the battery 300 has good cycle performance and high energy efficiency, so that the battery 300 has a long service life. When the battery 300 is used to power the device body 410, the battery 300 can provide a stable power supply for the device body 410 to enable the device body 410 to operate normally.

[0131] Optionally, the power-consuming device 400 in the embodiment of the present application may be, but is not limited to, a portable electronic device such as a mobile phone, tablet computer, laptop computer, desktop computer, smart bracelet, smart watch, e-reader, game console, or similar. It may also be a vehicle such as a car, truck, sedan, van, freight train, high-speed train, electric vehicle, or other similar vehicle. Furthermore, it may also be various household appliances. The power-consuming device 400 in the embodiment of FIG. 7 of the present application is an energy storage battery cabinet.

[0132] It can be understood that the electrical device 400 described in this embodiment is merely a form of the electrical device 400 used by the battery 300, and should not be understood as a limitation on the electrical device 400 provided in this application, nor should it be understood as a limitation on the electrical device 400 provided in each embodiment of this application.

[0133] Mentioning "embodiments" and "implementation methods" in this application means that the specific features, structures or characteristics described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrases in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described in this application can be combined with other embodiments. In addition, it should be understood that the features, structures or characteristics described in the various embodiments of the present application can be arbitrarily combined to form another embodiment that does not deviate from the spirit and scope of the technical solution of the present application, unless there is a contradiction between them.

[0134] Finally, it should be noted that the above implementation modes are only used to illustrate the technical solutions of the present application and are not limiting. Although the present application has been described in detail with reference to the above preferred implementation modes, ordinary technicians in this field should understand that the technical solutions of the present application can be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present application.

Claims

1. An electrode plate, wherein: The electrode plate comprises: a current collector layer, and An active layer is provided on the surface of the current collector layer, and the active layer includes active particles and liquid-retaining particles; the liquid-retaining particles include an inner core and an outer shell, and the outer shell is provided around the outer periphery of the inner core, and the outer shell includes a plurality of sub-particles, each sub-particle having capillaries.

2. The electrode plate according to claim 1, wherein: The radial dimension d of the capillary pores is in the range of 2nm≤d≤30nm.

3. The electrode plate according to claim 1, wherein: In the housing, the distribution density a of the capillary pores is in the range of 0.4 cm 3 / g≤a≤3cm 3 / g.

4. The electrode plate according to claim 1, wherein: The particle size D1 of the sub-particles is in the range of 50 nm ≤ D1 ≤ 90 nm.

5. The electrode plate according to claim 1, wherein: The diameter of the inner core is D2, and the outer diameter of the liquid-retaining particle is D3, and the relationship is satisfied: 1:3≤D2:D3≤1:1.

2.

6. The electrode plate according to claim 5, wherein: The range of the diameter D2 of the core is: 80nm≤D2≤300nm.

7. The electrode plate according to claim 1, wherein: The core is selected from one or more synthetic polymers selected from acrylic acid, acrylic esters, acrylamide, acrylonitrile, butadiene, styrene and tetrafluoroethylene.

8. The electrode plate according to claim 1, wherein: The shell is selected from one of silane, silicon dioxide, silicate and aluminum oxide.

9. A battery, wherein: The battery comprises: Positive electrode; A diaphragm, the diaphragm being arranged on one side of the positive electrode plate; a negative electrode sheet, the negative electrode sheet being disposed on a side of the separator away from the positive electrode sheet, and at least one of the positive electrode sheet and the negative electrode sheet being the electrode sheet according to any one of claims 1 to 8; and An electrolyte solution at least soaks a portion of the positive electrode sheet and a portion of the negative electrode sheet.

10. The battery according to claim 9, wherein The positive electrode plate is the electrode plate according to any one of claims 1 to 8. In the active layer of the positive electrode plate, the mass fraction A1 of the liquid-retaining particles is in the range of: 0.4%≤A1≤1.2%.

11. The battery according to claim 9, wherein The negative electrode plate is the electrode plate according to any one of claims 1 to 8. In the active layer of the negative electrode plate, the mass fraction A2 of the liquid-retaining particles is in the range of: 0.2%≤A2≤0.8%.

12. An electrical device, wherein: The electrical equipment includes: Equipment body; The battery according to claim 9 to claim 11, wherein the battery is used to power the device body.

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