Battery, electronic device, and mobile device

Abstract

The present application provides a battery comprising: a first base separator and a second base separator, positioned on either side of an electrode plate and adjacent to each other; and a first type separator coating layer, adhered to an edge region of the first base separator and adhered to an edge region of the second base separator. The present application also provides a battery comprising: a second type separator coating layer adhered to an intermediate region of the base separator; and a third type separator coating layer adhered to an edge region of the first base separator, wherein the second type separator coating layer comprises an adhesive polymer having a first mass content and the third type separator coating layer comprises an adhesive polymer having a second mass content, the second mass content being greater than the first mass content. The present application provides a battery, electronic device, or mobile device that reduces the possibility of a short circuit between a positive electrode plate and a negative electrode plate.

Description

Technical Field

[0001]

[0001] This application claims priority to Chinese Patent Application No. 202011530559.7, filed with the China National Intellectual Property Administration on December 22, 2020, entitled "Battery, Electronic Device, and Mobile Device", the entire content of which is incorporated herein by reference.

[0002]

[0002] Technical Field This application relates to the technical field of batteries, particularly related to batteries, electronic devices, and mobile devices.

Background Art

[0003]

[0003] Currently, batteries are commercialized and widely used as secondary power supplies. In a battery, a separator is a porous electrochemically inert medium between the positive electrode plate and the negative electrode plate, which does not participate in the electrochemical reaction but is extremely important for the safety performance of the battery. When the battery is in a mechanically abused state or a thermally abused state, the edges of the separator contract, and this contraction increases the possibility of a short circuit between the positive electrode plate and the negative electrode plate, and in severe cases, it may even easily cause thermal runaway.

Summary of the Invention

[0004]

[0004] This application provides a battery, an electronic device, and a mobile device to reduce the possibility of a short circuit between the positive electrode plate and the negative electrode plate.

[0005]

[0005] According to a first aspect, a battery is provided, the battery comprising: A first electrode plate; A first base separator and a second base separator, the first base separator and the second base separator are two base separators adjacent to the first electrode plate, and the first base separator and the second base separator are respectively arranged on two sides of the first electrode plate, the first base separator and the second base separator; and A first type of separator coating layer, the first type of separator coating layer is adhered to a first edge region of the first base separator and also adhered to a second edge region of the second base separator, the first edge region and the second edge region are located on the same side of the battery, and the first edge region and the second edge region face each other, including the first type of separator coating layer.

[0006]

[0006] Optionally, the first type of separator coating layer has adhesiveness and high-temperature meltability.

[0007]

[0007] It should be understood that "arranged opposite to each other" may be understood as "arranged facing each other".

[0008]

[0008] In the present application, the first type of separator coating layer is arranged between two adjacent base separators. As a result, the side surface of the electrode plate that is close to the separator coating layer can be surrounded by the base separator, the first type of separator coating layer, and the base separator. In other words, one end of the electrode plate can be closed by the separator. This helps to reduce the possibility of short circuit between the positive electrode plate and the negative electrode plate.

[0009]

[0009] Also, the first type of separator coating layer is disposed in the edge region of the base separator, which helps to improve the tightness of the bond between the separator and the electrode plate and reduce the risk of lithium ion precipitation. Further, the first type of separator coating layer is disposed in the edge region of the base separator, which not only helps to improve the overall hot press uniformity of the electrode, but also helps to improve the bonding force between the electrode plate and the separator, thereby also helping to improve the cycle performance of the battery. Also, in thermal abuse scenarios, etc., due to the effect of the adhesive force, the separator becomes even less likely to shrink, thereby also helping to reduce the amount of deformation of the cell.

[0010]

[0010] Regarding the first aspect, in some implementations of the first aspect, the first type of separator coating layer is further adhered to the side edge of the first electrode plate.

[0011]

[0011] In the present application, when the first type of separator coating layer is adhered to the side edge of the electrode plate, it helps to improve the tightness of the bond between the separator coating layer and the electrode plate, thereby reducing the risk of lithium ion precipitation.

[0012]

[0012] When the first type of separator coating layer is not adhered to the side edge of the electrode plate, it helps to provide a margin for the shrinkage of the base separator.

[0013]

[0013] Regarding the first aspect, in some implementations of the first aspect, the battery further includes a second electrode plate and a third base separator; both the second base separator and the third base separator are adjacent to the second electrode plate; the second base separator is located between the first base separator and the third base separator; the first type of separator coating layer is further adhered to the third edge region of the second base separator, the side edge of the second base separator, and the fourth edge region of the third base separator; the side edge of the second base separator connects the second edge region and the third edge region; the third edge region and the fourth edge region are arranged opposite to each other and are located on the same side of the battery.

[0014]

[0014] Regarding the first aspect, in some implementations of the first aspect, the battery further includes a third electrode plate, a fourth base separator, and a fifth base separator; both the fourth base separator and the fifth base separator are adjacent to the third electrode plate; the second base separator is located between the first base separator and the fourth base separator, and the fourth base separator is located between the second base separator and the fifth base separator; the first type of separator coating layer is further adhered to the side edge of the second base separator, the side edge of the fourth base separator, the fifth edge region of the fourth base separator, and the sixth edge region of the fifth base separator; the second edge region, the side edge of the second base separator, the side edge of the fourth base separator, the fifth edge region, and the sixth edge region are all on the same side of the battery; the fifth edge region and the sixth edge region are arranged opposite to each other.

[0015] In the present application, the first type of separator coating layer extends across a plurality of base separators and is fused together at the edges of the plurality of base separators, which helps to improve the sealing property of the electrode plate and helps to significantly reduce the possibility of short circuit between the positive electrode plate and the negative electrode plate.

[0016] Regarding a first aspect, in some implementations of the first aspect, the battery further includes a second type of separator coating layer, the second type of separator coating layer is adhered to an intermediate region of the first base separator, the first type of separator coating layer is connected to the second type of separator coating layer, the second type of separator coating layer includes an adhesive polymer having a first mass content, the first type of separator coating layer includes an adhesive polymer having a second mass content, and the second mass content is greater than the first mass content.

[0017] In the present application, since the third type of separator coating layer has more adhesive polymer, the third type of separator coating layer can be filled between the second type of separator coating layer and the electrode plate, further improving the adhesion between the separator and the electrode plate, thereby reducing the risk of lithium-ion precipitation.

[0018] Also, an adhesive polymer having a higher mass content is disposed in the edge region of the base separator, which helps to improve the adhesion ability of the base separator in the edge region and helps to improve the adhesion between the electrode plate and the separator, thereby helping to improve the cycle performance of the battery and improve cell deformation. Further, due to the different contents, the adhesive polymer in the edge region may have a higher thickness, which helps to improve the overall hot press uniformity of the electrode.

[0019]

[0019] Regarding the first aspect, in some implementations of the first aspect, the second mass content rate is 0.4 g / m 2 to 5 g / m 2 is in between.

[0020]

[0020] Regarding the first aspect, in some implementations of the first aspect, the difference between the first mass content rate and the second mass content rate is 0.05 g / m 2 to 4.5 g / m 2 is in between.

[0021]

[0021] Regarding the first aspect, in some implementations of the first aspect, the adhesive polymer is: polyvinylidene fluoride, polyhexafluoropropylene, vinylidene fluoride - hexafluoropropylene copolymer, vinylidene fluoride - trichloroethylene copolymer, polyethylene - vinyl acetate copolymer, sodium carboxymethyl cellulose, styrene - butadiene rubber, polyacrylic acid, polyacrylate, polyacrylate ester, polyacrylonitrile, polyamide, polyimide, polyethylene oxide, cellulose acetate, cellulose acetate butyrate, cellulose acetate propionate, polyvinylpyrrolidone, polyvinyl acetate, polyvinyl ether, polymethyl methacrylate, and polytetrafluoroethylene, including at least one of them.

[0022]

[0022] Regarding the first aspect, in some implementations of the first aspect, the battery further includes an electrolyte. The solubility parameter of the first type of separator coating layer is the first solubility parameter, the solubility parameter of the electrolyte is the second solubility parameter, the first solubility parameter is less than or equal to the second solubility parameter, and the difference between the second solubility parameter and the first solubility parameter is less than or equal to a preset solubility parameter.

[0023]

[0023] In the present application, the solubility of the separator coating layer and the solubility of the electrolyte are appropriately set, which helps to control the compatibility of the separator coating layer in the electrolyte and thereby control the morphology of the separator coating layer in the electrolyte, so that the separator coating layers arranged facing each other fuse together to form a first type of separator coating layer. Also, the solubility of the separator coating layer and the solubility of the electrolyte are appropriately set, which helps to further improve the adhesiveness between the electrode plates, thereby improving the kinetic performance of the battery and reducing the polarization between the batteries.

[0024]

[0024] Regarding the first aspect, in some implementations of the first aspect, the preset solubility parameter is 5 (J / cm 3 ) 0.5 or less.

[0025]

[0025] Regarding the first aspect, in some implementations of the first aspect, the width of the first type of separator coating layer is between 0.1% and 45% of the width of the first electrode plate.

[0026]

[0026] According to the second aspect, a battery is provided, the battery comprising: a first base separator; a second type of separator coating layer, wherein the second type of separator coating layer is adhered to an intermediate region of the first base separator and the second type of separator coating layer comprises an adhesive polymer having a first mass content, the second type of separator coating layer; and A third type of separator coating layer, wherein the third type of separator coating layer is adhered to an edge region of a first base separator, the third type of separator coating layer is connected to a second type of separator coating layer, the third type of separator coating layer includes an adhesive polymer having a second mass content, the second mass content is greater than a first mass content, and the third type of separator coating layer is included.

[0027]

[0027] In the present application, since the third type of separator coating layer has more adhesive polymer, the third type of separator coating layer is filled between the second type of separator coating layer and the electrode plate to further improve the adhesion strength between the separator and the electrode plate, thereby reducing the risk of lithium ion precipitation.

[0028]

[0028] Also, an adhesive polymer having a higher mass content is disposed in the edge region of the base separator, which helps to improve the adhesion ability of the base separator in the edge region and helps to improve the adhesion force between the electrode plate and the separator, thereby helping to improve the cycle performance of the battery and improve cell deformation. Further, due to the different contents, the adhesive polymer in the edge region may have a higher thickness, which helps to improve the overall hot press uniformity of the electrode.

[0029]

[0029] Regarding a second aspect, in some implementations of the second aspect, the thickness of the second type of separator coating layer is less than or equal to the minimum thickness of the third type of separator coating layer.

[0030]

[0030] Regarding a second aspect, in some implementations of the second aspect, the second mass content is between 0.4 g / m 2 and 5 g / m 2 .

[0031]

[0031] Regarding the second aspect, in some implementations of the second aspect, the difference between the first mass content rate and the second mass content rate is 0.05 g / m 2 to 4.5 g / m 2 is in between.

[0032]

[0032] Regarding the second aspect, in some implementations of the second aspect, the battery further includes an electrolyte, the solubility parameter of the third type of separator coating layer is the first solubility parameter, the solubility parameter of the electrolyte is the second solubility parameter, the first solubility parameter is less than or equal to the second solubility parameter, and the difference between the second solubility parameter and the first solubility parameter is less than or equal to a preset solubility parameter.

[0033]

[0033] In the present application, the solubility of the separator coating layer and the solubility of the electrolyte are appropriately set, which helps to control the compatibility of the separator coating layer in the electrolyte and control the morphology of the separator coating layer in the electrolyte, thereby helping the separator coating layers arranged facing each other to fuse with each other to form the first type of separator coating layer. Also, the solubility of the separator coating layer and the solubility of the electrolyte are appropriately set, which helps to further improve the adhesiveness between the electrode plates, thereby improving the kinetic performance of the battery and reducing the polarization between the batteries.

[0034]

[0034] Regarding the second aspect, in some implementations of the second aspect, the preset solubility parameter is 5 (J / cm 3 ) 0.5 or less.

[0035]

[0035] Regarding the second aspect, in some implementations of the second aspect, the battery further includes an electrode plate, and the width of the third type of separator coating layer is between 0.1% and 45% of the width of the electrode plate.

[0036]

[0036] Regarding the second aspect, in some implementations of the second aspect, the adhesive polymer is: polyvinylidene fluoride, polyhexafluoropropylene, vinylidene fluoride - hexafluoropropylene copolymer, vinylidene fluoride - trichloroethylene copolymer, polyethylene - vinyl acetate copolymer, sodium carboxymethyl cellulose, styrene - butadiene rubber, polyacrylic acid, polyacrylate, polyacrylate, polyacrylonitrile, polyamide, polyimide, polyethylene oxide, cellulose acetate, cellulose acetate butyrate, cellulose acetate propionate, polyvinylpyrrolidone, polyvinyl acetate, polyvinyl ether, polymethyl methacrylate, and polytetrafluoroethylene, including at least one of them.

[0037]

[0037] According to the third aspect, an electronic device is provided, and the electronic device includes a battery according to any of the implementations of the first aspect and the second aspect.

[0038]

[0038] According to the fourth aspect, a mobile device is provided, and the mobile device includes a battery according to any of the implementations of the first aspect and the second aspect.

Brief Description of the Drawings

[0039]

Figure 1

[0039] Figure 1 is a schematic diagram of the structure of an electronic device.

Figure 2

[0040] Figure 2 is a diagram of the operating principle of a battery.

Figure 3

[0041] Figure 3 is a schematic diagram of the structure of a battery.

Figure 4

[0042] Figure 4 is a schematic diagram of the structure of a battery according to an embodiment of the present application.

Figure 5

[0043] Figure 5 is a schematic diagram of the structure of the intermediate region and the edge region.

Figure 6

[0044] FIG. 6 is a schematic diagram of a mechanism for processing a battery by using a hot press process according to an embodiment of the present application.

Figure 7

[0045] FIG. 7 is a schematic diagram of the structure of a battery according to an embodiment of the present application.

Figure 8

[0046] FIG. 8 is a schematic diagram of the structure of a battery according to an embodiment of the present application.

Figure 9

[0047] FIG. 9 is a schematic diagram of the structure of a battery according to an embodiment of the present application.

Figure 10

[0048] FIG. 10 is a schematic diagram of another mechanism for processing a battery by using a hot press process according to an embodiment of the present application.

Figure 11

[0049] FIG. 11 is a schematic diagram of yet another mechanism for processing a battery by using a hot press process according to an embodiment of the present application.

Figure 12

[0050] FIG. 12 is a schematic diagram of the structure of a battery according to an embodiment of the present application.

Figure 13

[0051] FIG. 13 is a schematic diagram of the structure of a battery according to an embodiment of the present application.

Figure 14

[0052] FIG. 14 is a schematic diagram of a mechanism for processing a battery by using a hot press process according to an embodiment of the present application.

Figure 15

[0053] FIG. 15 is a schematic diagram of the structure of a battery according to an embodiment of the present application.

Embodiments for Carrying Out the Invention

[0040]

[0054] Hereinafter, the technical solutions in the present application will be described with reference to the accompanying drawings.

[0041]

[0055] Before describing the embodiments of the present application, the technical terms appearing in the present application will be described first.

[0042]

[0056] A primary cell can be considered as a device that converts chemical energy into electrical energy. The primary cell utilizes the potential difference between the positive electrode and the negative electrode to enable the flow of electrons between the positive electrode and the negative electrode.

[0043]

[0057] The positive electrode (cathode) can be considered as the electrode with a higher potential among the electrodes of the primary cell. In the discharging process, current can flow out from the positive electrode, and the positive electrode can gain electrons and have a reduction function. In the charging process, current flows to the positive electrode, and the positive electrode can lose electrons and have an oxidation function.

[0044]

[0058] The negative electrode (anode) can be considered as the electrode with a lower potential among the electrodes of the primary cell. In the discharging process, current flows to the negative electrode, and the negative electrode can lose electrons and have an oxidation function. In the charging process, current can flow out from the negative electrode, and the negative electrode can gain electrons and have a reduction function.

[0045]

[0059] An electrolyte can be considered as a medium used for ion exchange between the positive electrode and the negative electrode of the battery.

[0046]

[0060] A separator can be considered as a medium used to separate the positive electrode plate from the negative electrode plate to prevent short - circuit due to direct contact between the positive and negative electrode plates. The basic functions of the separator are porosity (which can provide channels for ion transmission) and insulation (which can prevent electrical leakage). The separator may include a base separator and a separator coating layer.

[0047]

[0061] The base separator may be the microporous film portion in the separator. The base separator may be used individually within the cell. The base separator can provide porosity and insulation.

[0048]

[0062] The separator coating layer may be a thin film attached to at least one surface of the base separator. The separator coating layer may be attached to the base separator by adhesion. The separator coating layer may be used to improve the performance of the separator, for example, to improve the heat resistance and adhesiveness of the separator.

[0049]

[0063] The cell (core or cell) can be considered as the part having the power storage function in the battery. The cell may include a positive electrode plate and a negative electrode plate.

[0050]

[0064] Heat abuse can be considered as the abuse of the cell in terms of heat (or high temperature). Using a hot box, tests related to heat abuse can be performed on the cell (for example, baking the cell at a high temperature (≥130°C)).

[0051]

[0065] Mechanical abuse can be considered as the abuse of the cell in terms of mechanics. Tests related to mechanical abuse can be performed on the cell by using, for example, a nail penetration test, an impact test, etc.

[0052]

[0066] The heat shrinkage rate may be the size change rate of the separator before and after heating in the machine direction / transverse direction (where the machine direction MD is the direction along the long side of the separator, and the transverse direction TD is perpendicular to MD, i.e., the direction along the short side of the separator). The method for testing the heat shrinkage rate may include the following: measuring the size of the separator in the machine / transverse direction (MD / TD); placing the separator with a specific size in the machine / transverse direction (MD / TD) in a thermostatic bath. The thermostatic bath is heated to a specific temperature; measuring the size of the separator in the machine / transverse (MD / TD) direction after heating.

[0053]

[0067] The mass content may be the mass of the substance per unit area.

[0054]

[0068] The solubility parameter (SP) may be a physical constant of the miscibility of liquid materials, and it can be calculated using the formula SP = (E / V) 1 / 2 where E is the cohesive energy, V is the volume, and E / V is the cohesive energy density.

[0055]

[0069] The solution provided in the embodiments of the present application can further be applied to electronic devices or mobile devices.

[0056]

[0070] The electronic device may be, for example, a terminal consumer product or 3C electronic product (electronic product for computer, communication, or consumer), such as a mobile phone, mobile power supply, portable computer, tablet computer, e-reader, notebook computer, digital camera, wearable device, in-vehicle terminal, headset, etc.

[0057]

[0071] The mobile device may be, for example, a vehicle, electric skateboard, electric bicycle, etc.

[0058]

[0072] FIG. 1 is a schematic diagram of the structure of an electronic device 100 according to an embodiment of the present application. The embodiment shown in FIG. 1 will be described using an example in which the electronic device 100 is a mobile phone.

[0059]

[0073] The electronic device 100 includes a housing 10, a display screen 20, and a circuit board assembly 30. Specifically, the housing 10 includes a frame and a back cover. The frame surrounds the outer periphery of the display screen 20 and also surrounds the outer periphery of the back cover. The circuit board assembly 30 can be disposed using the cavity formed by the display screen 20, the frame, and the back cover. In one example, both the display screen 20 and the circuit board assembly 30 can be disposed in the housing 10. The electronic device 100 can further include a battery 40 configured to supply power to the circuit board assembly 30. The battery 40 can be, for example, a lithium-ion secondary battery, a sodium-ion secondary battery, a potassium-ion secondary battery, a magnesium-ion secondary battery, a zinc-ion secondary battery, or an aluminum-ion secondary battery.

[0060]

[0074] Figure 2 is a diagram of the operating principle of battery 40. The constituent elements that form the core of battery 40 can include a positive electrode plate 101, a negative electrode plate 102, an electrolyte 103, and a separator 104 (auxiliary parts corresponding to connections, loops, etc. are not shown). The positive electrode plate 101 and the negative electrode plate 102 can deintercalate lithium ions in order to store and release energy. As shown in Figure 2, the movement of Li+ to the left (positive electrode) is an energy release process, and the movement of Li+ to the right (negative electrode) is an energy storage process. The electrolyte 103 may be a carrier for the transmission of lithium ions between the positive electrode plate 101 and the negative electrode plate 102. The positive electrode plate 101 and the negative electrode plate 102 are the main energy storage parts of battery 40, and may reflect the energy density, cycle performance, and safety performance of the cell. Lithium ions can pass through the separator 104, but the separator 104 is not conductive. Therefore, the separator 104 can separate the positive electrode plate 101 from the negative electrode plate 102 and prevent a short circuit between the positive electrode plate 101 and the negative electrode plate 102. The basic characteristics of the separator 104 are porosity (the ability to provide channels for ion transmission) and insulation (preventing electrical leakage).

[0061]

[0075] Figure 3 is a schematic diagram of the structure of battery 40. Battery 40 may include multiple layers of the positive electrode plate 101, multiple layers of the negative electrode plate 102, and multiple layers of the separator 104. The positive electrode plate 101 and the negative electrode plate 102 are stacked at intervals. The layer 102 of the negative electrode plate is arranged between two adjacent positive electrode plates 101, and the layer 101 of the positive electrode plate is arranged between two adjacent negative electrode plates 102. Also, a separator 104 is arranged between the adjacent positive electrode plate 101 and the negative electrode plate 102 to prevent a short circuit between the positive electrode plate 101 and the negative electrode plate 102. The multiple layers of the positive electrode plate 101, the multiple layers of the negative electrode plate 102, and the multiple layers of the separator 104 may be immersed in the electrolyte 103 shown in Figure 2.

[0062]

[0076] The positive electrode plate 101 may include a positive electrode current collector and a positive electrode active material disposed on the positive electrode current collector. The positive electrode active material may include, but is not limited to, a composite metal oxide of lithium (such as lithium cobalt oxide (LCO) or lithium nickel cobalt manganese oxide (NMC)), a polyanion-lithium compound LiMx(PO4)y (where M is Ni, Co, Mn, Fe, Ti, or V, 0≦x≦5, and 0≦y≦5), etc.

[0063]

[0077] For example, the method of manufacturing a positive electrode plate may include the following: First, an adhesive (such as polyvinylidene difluoride (PVDF)) is dissolved in N-methyl-2-pyrrolidone (NMP) to obtain a 7.0% PVDF binder solution. Then, a conductive liquid of carbon nanotubes (CNT) is added and uniformly dispersed. Thereafter, the active material lithium cobalt oxide (LCO) is added and uniformly stirred and mixed to form a positive electrode slurry. Further, by using a coating device, the positive electrode slurry is uniformly coated on both sides of an aluminum foil, dried using a laboratory oven, and the NMP solvent is removed. Finally, the coated electrode plate undergoes processes such as cold pressing, stripping, and tab welding to obtain a completed positive electrode plate. The ratio of the positive electrode may be, for example, LCO:CNTs:PVDF being 98.8%:0.02%:1.0%.

[0064]

[0078] In another example, the method for manufacturing a positive electrode plate may include the following: First, an adhesive (e.g., polyvinylidene difluoride (PVDF)) is dissolved in N-methyl-2-pyrrolidone (NMP) to obtain a 7.0% PVDF binder solution. Next, a carbon nanotube (CNT) conductive liquid is added and uniformly dispersed. Then, the active material lithium nickel cobalt manganese oxide (NMC) is added and uniformly stirred and mixed to form a positive electrode slurry. Further, by using a coating device, the positive electrode slurry is uniformly coated on both sides of an aluminum foil, dried using a laboratory oven, and the NMP solvent is removed. Finally, the coated electrode plate undergoes processes such as cold pressing, stripping, and tab welding to obtain a completed positive electrode plate. The ratio of the positive electrode may be, for example, NMC:CNTs:SP:PVDF being 97.5%:0.5%:1.0%:1.0%.

[0065]

[0079] The negative electrode plate 102 may include a negative electrode current collector and a negative electrode active material disposed on the negative electrode current collector. The negative electrode active material includes, but is not limited to, at least one of metallic lithium, lithium alloy, lithium titanate, natural graphite, artificial graphite, MCMB, amorphous carbon, carbon fiber, carbon nanotube, hard carbon, soft carbon, graphene, graphene oxide, silicon, silicon-carbon compound, silicon-oxygen compound, and silicon-metal compound.

[0066]

[0080] In one example, the method for manufacturing a negative electrode plate may include the following: First, artificial graphite and conductive carbon black (SP) are kneaded and dry-blended to make the artificial graphite and conductive carbon black uniform. Next, 25% of a pre-stirred sodium alginate (CMC) binder solution is added and kneaded and mixed. Then, the remaining CMC and deionized water are added and rapidly dispersed to form a mixed negative electrode slurry. Further, the sieved mixed negative electrode slurry is uniformly coated on both sides of a copper foil by using a coating device and dried using a laboratory oven. Finally, the coated electrode plate undergoes processes such as cold pressing, stripping, and tab welding to obtain a completed negative electrode plate. The ratio of the negative electrode may be, for example, graphite:SP:CMC:styrene-butadiene rubber (SBR) being 96.8%:0.6%:1.2%:1.2%.

[0067]

[0081] Separator 104 may include, for example, a base separator and a separator coating layer.

[0068]

[0082] The base separator may be a porous insulating material. Lithium ions can pass through the pores in the base separator (the pores in the base separator can be considered as transmission channels for lithium ions). As the main component of separator 104, the base separator is required to have performances such as chemical inertness, electrochemical inertness, porosity, electronic insulation, high ductility and malleability, high membrane rupture temperature, and low hole blocking temperature.

[0069]

[0083] The base separator may include at least one of, for example, polyethylene (PE), polypropylene (PP), poly-alpha-olefin, polyethylene terephthalate, polymethylpentene, polybutene, polyimide, polyamide, polyester, polyurethane, polycarbonate, cyclic olefin copolymer, polybenzimidazole, poly-benzobisoxazole, aramid fiber, etc. The polymer form of the base separator may include one or more of, for example, copolymer, blend, mixture, and combination.

[0070]

[0084] The separator coating layer may be attached to at least one surface of the base separator. As a result, the separator 104 has performances such as high ductility and malleability, high film breaking temperature, and low hole closing temperature. Also, the separator coating layer may have other performances such as having high adhesion. The separator coating layer may include an organic coating layer, an inorganic coating layer, and / or an organic-inorganic composite coating layer.

[0071]

[0085] The inorganic coating layer may include a ceramic coating layer. The ceramic coating layer may include at least one of, for example, aluminum oxide, silicon oxide, titanium oxide, zirconium oxide, zinc oxide, barium oxide, magnesium oxide, beryllium oxide, calcium oxide, thoria, aluminum nitride, titanium nitride, aluminum hydroxide, boehmite, apatite, aluminum hydroxide, magnesium hydroxide, barium sulfate, boron nitride, silicon carbide, silicon nitride, cubic boron nitride, hexagonal boron nitride, graphite, graphene, mesoporous molecular sieve (MCM-41, SBA-15), etc.

[0072]

[0086] The organic coating layer can include at least one of polyvinylidene fluoride, polyhexafluoropropylene, vinylidene fluoride-hexafluoropropylene copolymer, vinylidene fluoride-trichloroethylene copolymer, polyethylene-vinyl acetate copolymer, sodium carboxymethyl, styrene-butadiene rubber, polyacrylic acid, polyacrylate, polyacrylate, polyacrylonitrile, polyamide, polyimide, polyethylene oxide, cellulose acetate, cellulose acetate butyrate, cellulose acetate propionate, polyvinyl pyrrolidone, polyvinyl acetate, polyvinyl ether, polymethyl methacrylate, polytetrafluoroethylene, etc.

[0073]

[0087] The organic-inorganic composite coating layer can be manufactured by mixing an inorganic coating layer and an organic coating layer.

[0074]

[0088] In a thermally harsh usage situation, the edge portion of the separator tends to shrink towards the middle region of the separator. A method to improve the tendency to shrink is to adhere the separator coating layer to the surface of the base separator (for example, the edge region and / or the middle region of the base separator) with an adhesive. The separator coating layer can melt and crosslink at high temperature and adhere to the electrode plate (for example, the positive electrode plate and / or the negative electrode plate). This helps to offset the shrinking force of the base separator, thereby helping to reduce the possibility of short circuit between the positive electrode plate and the negative electrode plate.

[0075]

[0089] Regarding the energy density of the battery, the market has increasingly high demands. A method to improve the energy density of the battery is to compress the thickness of the separator. However, the thickness of the separator is thin. As a result, the separator becomes more prone to shrinkage, the adhesive force of the separator becomes weak, and the possibility of short circuit between the positive electrode plate and the negative electrode plate cannot be effectively reduced.

[0076]

[0090] FIG. 4 is a schematic diagram of the structure of the battery 40 according to the embodiment of the present application.

[0077]

[0091] The battery 40 can include a plurality of positive electrode plates 101, a plurality of negative electrode plates 102, and a plurality of base separators 1041, which are stacked and arranged at intervals. The white rectangles in FIG. 4 may be used to represent the positive electrode plates 101, the black rectangles in FIG. 4 may be used to represent the negative electrode plates 102, and the rectangles with slashes in FIG. 4 may be used to represent the base separators 1041. One negative electrode plate 102 is arranged between any two adjacent positive electrode plates 101, one positive electrode plate 101 is arranged between any two adjacent negative electrode plates 102, and one base separator 1041 is arranged between any adjacent positive electrode plate 101 and negative electrode plate 102. Optionally, in the example of FIG. 4, the base separator 1041 may be adhered between the positive electrode plate 101 and the negative electrode plate 102.

[0078]

[0092] The battery 40 can further include a first type of separator coating layer 1042. The first type of separator coating layer 1042 may be adhesive or may be melted and cross-linked at a high temperature (in the field of batteries, a temperature exceeding 40°C to 60°C may sometimes be understood as a high temperature). In other words, the first type of separator coating layer 1042 may contain an adhesive polymer. In FIG. 4, a black pattern filled with a white grid is used to represent the first type of separator coating layer 1042. The first type of separator coating layer 1042 may be adhered to the edge region of the base separator 1041 (i.e., part or all of the first type of separator coating layer may be adhered to the edge region of the base separator 1041). Also, the first type of separator coating layer 1042 can be adhered between the first base separator 10411 and the second base separator 10412, and the first base separator 10411 and the second base separator 10412 are adjacent to the same electrode plate. Specifically, the first type of separator coating layer 1042 is adhered to the first edge region of the first base separator 10411 and the second edge region of the second base separator 10412. The first edge region and the second edge region are arranged opposite to each other, that is, the first edge region and the second edge region are located on the same side of the electrode plate. The first base separator 10411, the first type of separator coating layer 1042, and the second base separator 10412 can surround the edge of the electrode plate, and the electrode plate is located between the first base separator 10411 and the second base separator 10412.

[0079]

[0093] Hereinafter, with reference to FIG. 5, possible definitions for the intermediate region and the edge region will be described. In FIG. 5, a pattern filled with squares is used to represent the edge region. In FIG. 5, a pattern filled with diamonds is used to represent the intermediate region. It is assumed that the central axis in the lateral direction of the battery 40 (or the electrode plate, the base separator 1041, etc.) is the first central axis (the lateral direction TD may be understood as the width direction of the battery 40, and the machine direction MD may be understood as the length direction of the battery 40. The size of the battery 40 in the length direction is usually larger than the size of the battery 40 in the width direction). The intermediate region can be defined as the region where the distance to the first central axis is shorter than a first preset distance. The edge region can be defined as the region where the distance to the first central axis is longer than a first preset distance. The distance from the interface between the intermediate region and the edge region to the first central axis may be the first preset distance. For example, the first preset distance may be about 1 / 2 of the width of the electrode plate in the lateral direction.

[0080]

[0094] In another example, it is assumed that the central axis in the machine direction of the battery 40 (or the electrode plate, the base separator 1041, etc.) is the second central axis. The intermediate region can be defined as the region where the distance to the second central axis is shorter than a second preset distance. The edge region can be defined as the region where the distance to the second central axis is longer than a second preset distance. The distance from the interface between the intermediate region and the edge region to the second central axis may be the second preset distance. For example, the second preset distance may be about 1 / 2 of the width of the electrode plate in the machine direction.

[0081]

[0095] In order to effectively prevent a short circuit from occurring between the positive electrode plate 101 and the negative electrode plate 102, it should be understood that the base separator 1041 usually covers the entire area of the electrode plate, and the edge of the base separator 1041 may extend beyond the edge contour of the electrode plate.

[0082]

[0096] In one example, the fact that the separator coating layer 1042 of the first type is adhered to the edge region of the base separator 1041 means that the separator coating layer 1042 of the first type is adhered to the base separator 1041, and the separator coating layer 1042 of the first type includes a portion located outside the outer periphery of the electrode plate, that is, it may mean that the separator coating layer 1042 of the first type includes a portion that does not cover the outer periphery of the electrode plate.

[0083]

[0097] In another example, the fact that the separator coating layer 1042 of the first type is adhered to the edge region of the base separator 1041 means that the separator coating layer 1042 of the first type is adhered to the base separator 1041, and it may mean that the separator coating layer 1042 of the first type may include a first portion that covers the outer periphery of the electrode plate and a second portion located outside the outer periphery of the electrode plate.

[0084]

[0098] Optionally, the width of the separator coating layer 1042 of the first type can be 0.1% to 45% of the width of the electrode plate.

[0085]

[0099] Optionally, the width of the separator coating layer 1042 of the first type can be 0.5% to 5.0% of the width of the electrode plate.

[0086]

[0100] Optionally, the separator coating layer 1042 of the first type includes an adhesive polymer having a mass content of 0.4 g / m 2 to 5 g / m 2 thereof.

[0087]

[0101] In one example, the separator coating layer 1042 of the first type has a mass content of 0.5 g / m 2It is possible to include an adhesive polymer. The method of forming the slurry of the first type of separator coating layer 1042 may include the following: The raw materials of the coating layer are obtained based on a mass ratio. In this case, the polytetrafluoroethylene copolymer occupies 47.5 parts, deionized water occupies 50 parts, an aqueous wetting agent occupies 1.0 part, and an aqueous dispersant occupies 1.5 parts. Next, the polytetrafluoroethylene copolymer is added to deionized water and dispersed at high speed with a high-speed disperser to obtain a slurry dispersion. In this case, the specific rotation speed may be, for example, 15000 r / min, and the dispersion time may be, for example, 2 h. Then, the completely dissolved aqueous dispersant and aqueous wetting agent are added and stirred and pulverized sufficiently. In this case, the stirring and pulverizing time may be, for example, 3 h. Finally, evacuation and defoaming are performed to obtain a uniformly mixed slurry of the first type of separator coating layer 1042.

[0088]

[0102] In another example, the first type of separator coating layer 1042 may contain an adhesive polymer with a mass content of 0.62 g / m 2 It is possible to include an adhesive polymer. The method of forming the slurry of the first type of separator coating layer 1042 may include the following: The raw materials of the coating layer are obtained based on a mass ratio. In this case, boehmite occupies 30 parts, deionized water occupies 46 parts, an adhesive occupies 13.5 parts, an aqueous wetting agent occupies 1.0 part, and an aqueous dispersant occupies 1.5 parts. Next, the boehmite is added to deionized water and dispersed at high speed with a high-speed disperser to obtain a slurry dispersion. In this case, the specific rotation speed may be, for example, 15000 r / min, and the dispersion time may be, for example, 2 h. Then, the completely dissolved aqueous dispersant and aqueous wetting agent are added and stirred and pulverized sufficiently. In this case, the stirring and pulverizing time may be, for example, 3 h. Finally, evacuation and defoaming are performed to obtain a uniformly mixed slurry of the first type of separator coating layer 1042.

[0089]

[0103] In yet another example, the first type of separator coating layer 1042 can include an adhesive polymer having a mass content of 0.62 g / m 2 The method of forming the slurry of the first type of separator coating layer 1042 can include the following: the raw materials of the coating layer are obtained based on a mass ratio, in which case, polyvinylidene fluoride - hexafluoropropylene occupies 51.5 parts, deionized water occupies 46 parts, an aqueous wetting agent occupies 1.0 part, and an aqueous dispersant occupies 1.5 parts. Next, polyvinylidene fluoride - hexafluoropropylene is added to deionized water and dispersed at high speed with a high - speed disperser to obtain a slurry dispersion. In this case, the specific rotation speed can be, for example, 15000 r / min, and the dispersion time can be, for example, 2 h. Then, a completely dissolved aqueous dispersant and an aqueous wetting agent are added, and stirred and pulverized sufficiently. In this case, the stirring and pulverizing time can be, for example, 3 h. Finally, vacuuming and defoaming are performed to obtain a uniformly mixed slurry of the first type of separator coating layer 1042.

[0090]

[0104] When the mass content of the adhesive polymer is 0.6 g / m 2 The slurry ratio of the first type of separator coating layer 1042 can include, for example, those in which polyvinylidene fluoride - hexafluoropropylene occupies 47.5 parts, deionized water occupies 50 parts, an aqueous wetting agent occupies 1.0 part, and an aqueous dispersant occupies 1.5 parts.

[0091]

[0105] In yet another example, the first type of separator coating layer 1042 has a mass content of 0.45 g / m 2It is possible to include an adhesive polymer. A method for forming a slurry of the first type of separator coating layer 1042 may include the following: the raw materials of the coating layer are obtained based on the obtained mass ratio. In this case, the polyhexafluoropropylene copolymer occupies 52.0 parts, deionized water occupies 45.5 parts, an aqueous wetting agent occupies 1.0 part, and an aqueous dispersant occupies 1.5 parts. Next, the polyhexafluoropropylene copolymer is added to the deionized water and dispersed at high speed with a high-speed disperser to obtain a slurry dispersion. In this case, the specific rotation speed may be, for example, 15000 r / min, and the dispersion time may be, for example, 2 h. Then, the completely dissolved aqueous dispersant and aqueous wetting agent are added, and stirred and pulverized sufficiently. In this case, the stirring and pulverizing time may be, for example, 3 h. Finally, evacuation and defoaming are performed to obtain a uniformly mixed slurry of the first type of separator coating layer 1042.

[0092]

[0106] Optionally, the first type of separator coating layer 1042 contains an adhesive polymer having a mass content of 0.8 g / m 2 to 2.5 g / m 2 thereof.

[0093]

[0107] Optionally, the crystallinity of the first type of separator coating layer 1042 is less than 80%.

[0094]

[0108] Optionally, the crystallinity of the first type of separator coating layer 1042 may be 50.0% to 80.0%.

[0095]

[0109] Optionally, the solubility parameter of the first type of separator coating layer 1042 is the first solubility parameter, and the solubility parameter of the electrolyte in the battery is the second solubility parameter. The first solubility parameter is less than or equal to the second solubility parameter, and the difference between the second solubility parameter and the first solubility parameter is less than a preset solubility parameter.

[0096]

[0110] In one example, the first solubility parameter is 20 to 26 ± 1 (J / cm 3 ) 0.5 and the second solubility parameter is 26 ± 1 (J / cm 3 ) 0.5 .

[0097]

[0111] In one example, the pre-set solubility parameter is 5 (J / cm 3 ) 0.5 or less.

[0098]

[0112] Since the solubility parameter of the first type of separator coating layer 1042 is smaller than that of the electrolyte, the first type of separator coating layer 1042 does not completely dissolve in the electrolyte.If the solubility parameter of the first type of separator coating layer 1042 is much larger than that of the electrolyte, the first type of separator coating layer 1042 will melt excessively with the electrolyte, and it is difficult for the first type of separator coating layer 1042 to completely wrap around the side edge 10414 of the electrode plate. Referring to FIGS. 4 and 5, in the embodiment of the present application, the width of the electrode plate in the lateral direction and the machine direction is large, the thickness direction of the electrode plate is perpendicular to both the lateral direction and the machine direction, and the surface of the electrode plate in the thickness direction may be referred to as the side edge 10414 of the electrode plate. The difference between the solubility parameter of the first type of separator coating layer 1042 and the solubility parameter of the electrolyte is small. As a result, the separator coating layers arranged opposite to each other can be fused to form the first type of separator coating layer 1042, and the first type of separator coating layer 1042 is further helpful in improving the adhesion between the electrode plates, thereby contributing to the improvement of the battery's kinetic performance and the reduction of the bias between batteries.

[0099]

[0113] The adhesive polymer can include, for example, at least one of polyvinylidene fluoride, polyhexafluoropropylene, vinylidene fluoride - hexafluoropropylene copolymer, vinylidene fluoride - trichloroethylene copolymer, polyethylene - vinyl acetate copolymer, sodium carboxymethyl cellulose, styrene - butadiene rubber, polyacrylic acid, polyacrylate, polyacrylamide, polyacrylonitrile, polyamide, polyimide, polyethylene oxide, cellulose acetate, cellulose acetate butyrate, cellulose acetate propionate, polyvinylpyrrolidone, polyvinyl acetate, polyvinyl ether, polymethyl methacrylate, and polytetrafluoroethylene.

[0100]

[0114] FIG. 6 is a schematic diagram of a mechanism for processing the battery 40 using the hot - press process according to an embodiment of the present application. The upper diagram of FIG. 6 (i.e., the diagram located above the arrow in FIG. 6) is a schematic diagram of the structure of the battery 40 before the hot - press process. The lower diagram of FIG. 6 (i.e., the diagram located below the arrow in FIG. 6) is a schematic diagram of the structure of the battery 40 after the hot - press process.

[0101]

[0115] The hot - press process can be, for example, a process of forming and activating the raw materials of the battery 40 by pressurization, heating, etc. The hot - press process may be executed, for example, after processes such as stacking or winding. In the example shown in FIG. 6, the parameters in the hot - press process may include hot - press pressure, hot - press temperature, and hot - press time. In one example, the hot - press pressure may be from 0.1 MPa to 2.0 MPa, the hot - press temperature may be from 25°C to 100°C, and the hot - press time may be from 20 minutes to 300 minutes. In another example, the hot - press pressure may be from 0.5 MPa to 1.0 MPa, the hot - press temperature may be from 60°C to 90°C, and the hot - press time may be from 60 minutes to 150 minutes.

[0102]

[0116] The battery 40 can include a positive electrode plate 1011, a positive electrode plate 1012, a negative electrode plate 1021, and a negative electrode plate 1022 that are sequentially stacked. The positive electrode plate 1011 and the positive electrode plate 1012 may be two adjacent positive electrode plates. The negative electrode plate 1021 and the negative electrode plate 1022 may be two adjacent negative electrode plates. The negative electrode plate 1021 is located between the positive electrode plate 1011 and the positive electrode plate 1012, and the positive electrode plate 1012 is located between the negative electrode plate 1021 and the negative electrode plate 1022.

[0103]

[0117] The battery 40 can further include a base separator 10411, a base separator 10412, and a base separator 10413. The base separator 10412 may be located between the base separator 10411 and the base separator 10413.

[0104]

[0118] The base separator 10411 is located between the positive electrode plate 1011 and the negative electrode plate 1021, and the base separator 10411 may be adhered to the positive electrode plate 1011. Optionally, there may be a specific gap between the base separator 10411 and the negative electrode plate 1021.

[0105]

[0119] The base separator 10412 is located between the negative electrode plate 1021 and the positive electrode plate 1012, and the base separator 10412 may be adhered to the negative electrode plate 1021. Optionally, there may be a specific gap between the base separator 10412 and the positive electrode plate 1012.

[0106]

[0120] The base separator 10413 is located between the positive electrode plate 1012 and the negative electrode plate 1022, and the base separator 10413 may be adhered to the positive electrode plate 1012. Optionally, there may be a specific gap between the base separator 10413 and the negative electrode plate 1022.

[0107]

[0121] As shown in the upper figure of FIG. 6, the separator coating layer 10451 is adhered to the edge region of the base separator 10411, and the separator coating layer 10451 is disposed on the surface of the base separator 10411 that is close to the base separator 10412. The separator coating layer 10452 is adhered to the edge region of the base separator 10412, and the separator coating layer 10452 is disposed on the surface of the base separator 10412 that is close to the base separator 10411. Both the separator coating layer 10451 and the separator coating layer 10452 are separator coating layers having adhesiveness that can melt at high temperatures. The separator coating layer 10451 and the separator coating layer 10452 can be disposed on the same side of the negative electrode plate 1021.

[0108]

[0122] Optionally, the widths of the separator coating layer 10451 and the separator coating layer 10452 may be 0.1% to 45% of the width of the negative electrode plate 1021.

[0109]

[0123] Optionally, the widths of the separator coating layer 10451 and the separator coating layer 10452 may be 0.5% to 5.0% of the width of the negative electrode plate 1021.

[0110]

[0124] Similarly, as shown in the upper figure of FIG. 6, the separator coating layer 10453 is adhered to the edge region of the base separator 10412, and the separator coating layer 10453 is disposed on the surface of the base separator 10412 that is close to the base separator 10413. The separator coating layer 10454 is adhered to the edge region of the base separator 10413, and the separator coating layer 10454 is disposed on the surface of the base separator 10413 that is close to the base separator 10412. Both the separator coating layer 10453 and the separator coating layer 10454 are separator coating layers having adhesiveness that can melt at high temperatures. The separator coating layer 10453 and the separator coating layer 10454 may be disposed on the same side of the positive electrode plate 1012.

[0111]

[0125] Optionally, the widths of the separator coating layer 10453 and the separator coating layer 10454 may be from 0.1% to 45% of the width of the positive electrode plate 1012.

[0112]

[0126] Optionally, the widths of the separator coating layer 10453 and the separator coating layer 10454 may be from 0.5% to 5.0% of the width of the positive electrode plate 1012.

[0113]

[0127] The hot press process can promote a strong bond between the base separator and the electrode plate. As shown in the lower figure of FIG. 6, after the hot press process, the base separator 10411 can be adhered to both the positive electrode plate 1011 and the negative electrode plate 1021, the base separator 10412 can be adhered to both the negative electrode plate 1021 and the positive electrode plate 1012, and the base separator 10413 can be adhered to both the positive electrode plate 1012 and the negative electrode plate 1022.

[0114]

[0128] Furthermore, the hot press process can promote the fusion of two first-type separator coating layers 1042 that are close to each other. As shown in the lower figure of FIG. 6, in the hot press process, the separator coating layer 10451 and the separator coating layer 10452 melt out under the influence of high temperature and pressure, flow and spread on the base separator 10411 and the base separator 10412, and then can fuse with each other to form a first-type separator coating layer 10421. Therefore, the first-type separator coating layer 10421 can be connected between the base separator 10411 and the base separator 10412. As a result, the side surface of the negative electrode plate 1021, which is close to the separator coating layer 10451 and the separator coating layer 10452, can be surrounded by the base separator 10411, the first-type separator coating layer 10421, and the base separator 10412. In other words, one end of the electrode plate can be closed by the separator. This helps to reduce the possibility of short circuit between the negative electrode plate 1021 and the nearby positive electrode plates (for example, the positive electrode plate 1011 and the positive electrode plate 1012).

[0115]

[0129] Similarly, the hot press process can fuse both the separator coating layer 10453 and the separator coating layer 10454 to form a first-type separator coating layer 10422. Therefore, the first-type separator coating layer 10422 can be connected between the base separator 10412 and the base separator 10413. As a result, the side surface of the positive electrode plate 1012, which is close to the separator coating layer 10453 and the separator coating layer 10454, can be surrounded by the base separator 10412, the first-type separator coating layer 10422, and the base separator 10413. This helps to reduce the possibility of short circuit between the positive electrode plate 1012 and the nearby negative electrode plates (for example, the negative electrode plate 1021 and the negative electrode plate 1022).

[0116]

[0130] Also, a separator coating layer that can melt at high temperatures is disposed in the edge region of the base separator, which helps improve the adhesion of the bond between the separator and the electrode plate, thereby reducing the risk of lithium ion precipitation. Further, a separator coating layer that can melt at high temperatures is disposed in the edge region of the base separator, which not only helps improve the hot press uniformity of the entire electrode, but also helps improve the bonding force between the electrode plate and the separator, and may help improve the cycle performance of the battery. Also, in situations such as thermal abuse, due to the influence of the adhesive force, it becomes even more difficult for the separator to shrink, which helps reduce the amount of deformation of the cell.

[0117]

[0131] In the example of FIG. 6, the first type of separator coating layer 10421 may alternatively be adhered to the side edge of the negative electrode plate 1021. Similarly, the first type of separator coating layer 10422 may be adhered to the side edge of the positive electrode plate 1012. In another example, as shown in FIG. 7, a gap may exist between the first type of separator coating layer 10421 and the side edge of the negative electrode plate 1021, i.e., the first type of separator coating layer 10421 may not be adhered to the side edge of the negative electrode plate 1021. Similarly, a gap may exist between the first type of separator coating layer 10422 and the side edge of the positive electrode plate 1012, i.e., the first type of separator coating layer 10422 may not be adhered to the side edge of the positive electrode plate 1012. This helps provide a margin against the shrinkage of the base separator.

[0118]

[0132] In the example shown in FIG. 6, the first type of separator coating layer 10421 can be disposed within a spaced-apart space formed between the base separator 10411 and the base separator 10412. Similarly, the first type of separator coating layer 10422 can be disposed within a spaced-apart space formed between the base separator 10412 and the base separator 10413. In another example, as shown in FIG. 8, a plurality of the first type of separator coating layers 10423 can extend across a plurality of base separators (e.g., base separator 10411, base separator 10412, base separator 10413) and may fuse together at the edges of the plurality of base separators. For example, after hot pressing, the separator coating layers 10451, 10452, 10453, 10454 (as shown in FIG. 6) on the same side of the battery 40 can all be fused together to form the first type of separator coating layer 10423 shown in FIG. 8. The first type of separator coating layer 10423 can be connected to all of the base separators 10411, 10412, 10413, and the first type of separator coating layer 10423 can wrap around the side edge 10415 of the base separator 10412. As described above, the first type of separator coating layer 10423 can be adhered to the first edge region of the base separator 10411 and the second edge region of the base separator 10412. Further, the first type of separator coating layer 10423 may be further adhered to the third edge region of the base separator 10412, the side edge 10415 of the base separator 10412, and the fourth edge region of the base separator 10413.The side edge 10415 is connected between the second edge region and the third edge region of the base separator 10412. The third edge region and the fourth edge region are arranged opposite to each other. The first edge region, the second edge region, the third edge region, the fourth edge region, and the side edge 10415 are all located on the same side of the battery 40.

[0119]

[0133] In the example shown in FIG. 8, the first type of separator coating layer 10423 may adhere to the side edge of the negative electrode plate 1021 and the side edge of the positive electrode plate 1012. Referring to FIG. 7, it can be understood that the first type of separator coating layer 10423 shown in FIG. 8 may not be attached to the side edge of the electrode plate. As shown in FIG. 9, the first type of separator coating layer 10423 may not adhere to the side edge of the negative electrode plate 1021 nor the side edge of the positive electrode plate 1012. In another possible example, the first type of separator coating layer 10423 may adhere to the side edge of at least one target electrode plate among the plurality of positive electrode plates 101 and the plurality of negative electrode plates 102 shown in FIG. 4, and it should be understood that it does not adhere to the side edge of the electrode plates other than at least one target electrode plate among the plurality of positive electrode plates 101 and the plurality of negative electrode plates 102. This helps to provide a margin for the shrinkage of the base separator.

[0120]

[0134] FIG. 10 is a schematic diagram of another mechanism for processing the battery 40 using the hot press process according to the embodiment of the present application. The upper diagram of FIG. 10 (i.e., the diagram located above the arrow in FIG. 10) is a schematic diagram of another structure of the battery 40 before the hot press process. The lower diagram of FIG. 10 (i.e., the diagram located below the arrow in FIG. 10) is a schematic diagram of another structure of the battery 40 after the hot press process. Similar to the example shown in FIG. 6, the battery 40 shown in FIG. 10 can include a positive electrode plate 1011, a positive electrode plate 1012, a negative electrode plate 1021, a negative electrode plate 1022, a base separator 10411, a base separator 10412, and a base separator 10413.

[0121]

[0135] As shown in the upper diagram of FIG. 10, the separator coating layer 10451 is adhered to the edge region of the base separator 10411, and the separator coating layer 10451 is disposed on the surface of the base separator 10411 that is close to the base separator 10412. The separator coating layer 10452 is adhered to the edge region of the base separator 10412, and the separator coating layer 10452 is disposed on the surface of the base separator 10412 that is close to the base separator 10411. Both the separator coating layer 10451 and the separator coating layer 10452 are separator coating layers having adhesiveness that can melt at high temperatures. The separator coating layer 10451 and the separator coating layer 10452 can be disposed on the same side of the negative electrode plate 1021.

[0122]

[0136] Different from the example shown in FIG. 6, in the example shown in FIG. 10, the separator coating layer 10453 shown in FIG. 6 may not be adhered to the surface of the base separator 10412 that is close to the base separator 10413, and the separator coating layer 10454 shown in FIG. 6 may not be adhered to the surface of the base separator 10413 that is close to the base separator 10412.

[0123]

[0137] Similar to the example shown in FIG. 6, as shown in the lower figure of FIG. 10, the hot press process promotes a strong bond between the base separator and the electrode plate.

[0124]

[0138] As shown in the lower figure of FIG. 10, it is possible to fuse the separator coating layer 10451 and the separator coating layer 10452 to form the first type of separator coating layer 10421, and both the separator coating layer 10451 and the separator coating layer 10452 are located between the base separator 10411 and the base separator 10412. Therefore, the first type of separator coating layer 10421 is connected between the base separator 10411 and the base separator 10412. As a result, the side surface of the negative electrode plate 1021 that is close to the separator coating layer 10451 and the separator coating layer 10452 can be surrounded by the base separator 10411, the first type of separator coating layer 10421, and the base separator 10412. Since neither the separator coating layer 10453 nor the separator coating layer 10454 shown in FIG. 6 is arranged between the base separator 10412 and the base separator 10413, the example shown in FIG. 10 does not need to have the first type of separator coating layer 10422 shown in FIG. 6.

[0125]

[0139] In the example shown in FIG. 10, the base separator and the separator coating layer surrounding the negative electrode plate help reduce the possibility of a short circuit between the negative electrode plate and the positive electrode plate adjacent to it. Compared with the examples shown in FIGS. 3 and 6, in the example shown in FIG. 10, less separator coating layer material is used to prevent a short circuit from occurring between the positive electrode plate and the negative electrode plate.

[0126]

[0140] FIG. 11 is a schematic diagram of yet another mechanism for processing the battery 40 by using the hot press process according to the embodiment of the present application. The upper diagram of FIG. 11 (i.e., the diagram located above the arrow in FIG. 11) is a schematic diagram of yet another structure of the battery 40 before the hot press process. The lower diagram of FIG. 11 (i.e., the diagram located below the arrow in FIG. 11) is a schematic diagram of yet another structure of the battery 40 after the hot press process. Similar to the example shown in FIG. 6, the battery 40 in FIG. 11 can include a positive electrode plate 1011, a positive electrode plate 1012, a negative electrode plate 1021, a negative electrode plate 1022, a base separator 10411, a base separator 10412, and a base separator 10413.

[0127]

[0141] Different from the example shown in FIG. 6, as shown in the upper diagram of FIG. 11, the separator coating layer 10451 shown in FIG. 6 may not be adhered to the surface of the base separator 10411 that is close to the base separator 10412, and the separator coating layer 10452 shown in FIG. 6 may not be adhered to the surface of the base separator 10412 that is close to the base separator 10411.

[0128]

[0142] As shown in the upper diagram of FIG. 11, the separator coating layer 10453 is adhered to the edge region of the base separator 10412, and the separator coating layer 10453 is disposed on the surface of the base separator 10412 that is close to the base separator 10413. The separator coating layer 10454 is adhered to the edge region of the base separator 10413, and the separator coating layer 10454 is disposed on the surface of the base separator 10413 that is close to the base separator 10412. Both the separator coating layer 10453 and the separator coating layer 10454 are separator coating layers having adhesiveness that melts at high temperatures. The separator coating layer 10453 and the separator coating layer 10454 can be disposed on the same side of the positive electrode plate 1012.

[0129]

[0143] Similar to the example shown in FIG. 6, as shown in the lower diagram of FIG. 11, the hot press process promotes a strong bond between the base separator and the electrode plate.

[0130]

[0144] As shown in the lower diagram of FIG. 11, it is possible to fuse the separator coating layer 10453 and the separator coating layer 10454 to form the first type of separator coating layer 10422, and both the separator coating layer 10453 and the separator coating layer 10454 are located between the base separator 10412 and the base separator 10413. Therefore, the first type of separator coating layer 10422 can be connected between the base separator 10412 and the base separator 10413. As a result, the side surface of the positive electrode plate 1012 that is close to the separator coating layer 10453 and the separator coating layer 10454 can be surrounded by the base separator 10412, the first type of separator coating layer 10422, and the base separator 10413. Since neither the separator coating layer 10451 nor the separator coating layer 10452 shown in FIG. 6 is disposed between the base separator 10411 and the base separator 10412, the example shown in FIG. 11 does not need to have the first type of separator coating layer 10421 shown in FIG. 6.

[0131]

[0145] In the example shown in FIG. 11, the separator coating layer and the base separator surrounding the positive electrode plate help reduce the possibility of a short circuit between the positive electrode plate and the nearby negative electrode plate. Compared with the examples shown in FIGS. 3 and 6, in the embodiment shown in FIG. 11, less separator coating layer material is used to prevent a short circuit from occurring between the positive electrode and the negative electrode.

[0132]

[0146] In the example shown in FIG. 10, the first type of separator coating layer 10423 can be disposed within a spaced-apart space formed between the base separator 10411 and the base separator 10412. In another example, the first type of separator coating layer 10423 can extend across a plurality of base separators (e.g., base separator 10411, base separator 10412, base separator 10413) and may be fused to each other at the edges of the plurality of base separators.

[0133]

[0147] As shown in FIG. 12, the first type of separator coating layer 10423 can be connected to all of the base separators 10411, 10412, 10413, and 10416. The base separator 10413 is located between the base separator 10412 and the base separator 10416. The base separator 10413 and the base separator 10416 may be adjacent to the same electrode plate. The base separator 10411 and the base separator 10412 are adhered to both sides of the negative electrode plate 1021, and the base separator 10413 and the base separator 10416 are adhered to both sides of the negative electrode plate 1022. The first type of separator coating layer 10423 can be further adhered not only to the first edge region of the base separator 10411 and the second edge region of the base separator 10412, but also to the fifth edge region of the base separator 10413 and the sixth edge region of the base separator 10416. The fifth edge region and the sixth edge region are disposed opposite to each other. Further, the first type of separator coating layer 10423 can further wrap around the side edge 10415 of the base separator 10412 and the side edge 10417 of the base separator 10413. The first edge region, the second edge region, the fifth edge region, the sixth edge region, the side edge 10415, and the side edge 10417 are located on the same side of the battery 40.

[0134]

[0148] Referring to FIGS. 9 and 12, it can be seen that the first type of separator coating layer 10423 may not be adhered to the side edges of the electrode plate. This helps to provide a margin for the shrinkage of the base separator.

[0135]

[0149] Referring to FIGS. 11 and 12, in another example, it can be seen that the base separator 10411 and the base separator 10412 can be adhered to both sides of the positive electrode plate, and the base separator 10413 and the base separator 10416 can be adhered to both sides of another positive electrode plate. Under the influence of surface tension and polarity, the edge region of the electrode plate tends to shrink towards the middle region of the electrode plate. As a result, the thickness of the electrode plate in the edge region is slightly thinner than the thickness of the electrode plate in the middle region. In other words, it is easier to adhere the separator to the middle region of the electrode plate, and it is more difficult to adhere the separator to the edge region of the electrode plate. As a result, the edge of the electrode plate may not be firmly adhered to the separator, that is, there may be a gap between the electrode plate and the separator. After the battery 40 is charged and discharged electrically multiple times, lithium ions may gather and precipitate in the gap between the electrode plate and the separator to form solid lithium. Due to the thin thickness of the separator and the ease with which solid lithium can penetrate the separator, the possibility of a short circuit between the positive electrode plate 101 and the negative electrode plate 102 is increased.

[0136]

[0150] FIG. 13 is a schematic diagram of the structure of the battery 40 according to an embodiment of the present application.

[0137]

[0151] The battery 40 can include a plurality of positive electrode plates 101, a plurality of negative electrode plates 102, and a plurality of base separators 1041 that are stacked and arranged at intervals. The white rectangles in FIG. 4 may be used to represent the positive electrode plates 101, the black rectangles in FIG. 4 may be used to represent the negative electrode plates 102, and the rectangles with slashes in FIG. 4 may be used to represent the base separators 1041. One negative electrode plate 102 is arranged between any two adjacent positive electrode plates 101, one positive electrode plate 101 is arranged between any two adjacent negative electrode plates 102, and one base separator 1041 is arranged between any adjacent positive electrode plate 101 and negative electrode plate 102. The base separator 1041 may be adhered between the positive electrode plate 101 and the negative electrode plate 102.

[0138]

[0152] The battery 40 may further include a second type of separator coating layer 1043 and a third type of separator coating layer 1044. The white pattern filled with black grids in FIG. 13 is used to represent the second type of separator coating layer 1043. The black pattern filled with white grids in FIG. 13 is used to represent the third type of separator coating layer 1044. The second type of separator coating layer 1043 and the third type of separator coating layer 1044 can be adhered to at least one surface of the base separator 1041.

[0139]

[0153] The second type of separator coating layer 1043 can be adhered to the intermediate region of the base separator 1041, and the third type of separator coating layer 1044 can be adhered to the edge region of the base separator 1041. (For the definitions of the intermediate region and the edge region, refer to the foregoing description and the example shown in FIG. 5. Details will not be described again here.) The second type of separator coating layer 1043 may be connected to the third type of separator coating layer 1044. The boundary between the second type of separator coating layer 1043 and the third type of separator coating layer 1044 may correspond to the boundary between the intermediate region and the edge region of the base separator 1041. There may be no gap between the second type of separator coating layer 1043 and the third type of separator coating layer 1044, and the possibility of a gap existing between the electrode plate and the separator may be minimized.

[0140]

[0154] In one example, the second type of separator coating layer 1043 is adhered to the base separator 1041 and completely covers the periphery of the electrode plate; also, the third type of separator coating layer 1044 is adhered to the base separator 1041 and is located outside the periphery of the electrode plate.

[0141]

[0155] In another example, the second type of separator coating layer 1043 is adhered to the base separator 1041 and covers a part of the electrode plate; also, the third type of separator coating layer 1044 includes a first part that is adhered to the base separator 1041 and covers the remaining part of the electrode plate, and a second part that is located outside the outer periphery of the electrode plate.

[0142]

[0156] Optionally, the width of the third type of separator coating layer 1044 can be set to be from 0.1% to 45% of the width of the electrode plate.

[0143]

[0157] Optionally, the width of the third type of separator coating layer 1044 can be 0.5% to 5.0% of the width of the electrode plate.

[0144]

[0158] Optionally, the crystallinity of the second type of separator coating layer 1043 is less than 80%.

[0145]

[0159] Optionally, the crystallinity of the second type of separator coating layer 1043 can be 50.0% to 80.0%.

[0146]

[0160] Optionally, the crystallinity of the third type of separator coating layer 1044 is less than 80%.

[0147]

[0161] Optionally, the crystallinity of the second type of separator coating layer 1043 can be 50.0% to 80.0%.

[0148]

[0162] Optionally, the solubility parameter of the third type of separator coating layer 1043 is the first solubility parameter, and the solubility parameter of the electrolyte in the battery is the second solubility parameter. The first solubility parameter is less than or equal to the second solubility parameter, and the difference between the second solubility parameter and the first solubility parameter is less than a preset solubility parameter.

[0149]

[0163] In one example, the first solubility parameter is 20 to 26 ± 1 (J / cm 3 ) 0.5 and the second solubility parameter is 26 ± 1 (J / cm 3 ) 0.5 .

[0150]

[0164] In one example, the preset solubility parameter is 5 (J / cm 3 ) 0.5 or less.

[0151]

[0165] Since the solubility parameter of the third type of separator coating layer 1043 is smaller than that of the electrolyte, the third type of separator coating layer 1043 may be compatible with the electrolyte. The solubility parameter of the third type of separator coating layer 1043 is slightly different from that of the electrolyte. Therefore, the third separator coating layer 1043 does not completely dissolve in the electrolyte, which helps the third type of separator coating layer 1043 to spread on the base separator.

[0152]

[0166] Both the second type of separator coating layer 1043 and the third type of separator coating layer 1044 may be adhesive and may be meltable at high temperatures (in the field of batteries, temperatures exceeding 40 °C to 60 °C may sometimes be understood as high temperatures). In other words, both the second type of separator coating layer 1043 and the third type of separator coating layer 1044 may contain an adhesive polymer. The second type of separator coating layer 1043 contains an adhesive polymer having a first mass content, and the third type of separator coating layer 1044 contains an adhesive polymer having a second mass content, where the first mass content is less than the second mass content. FIG. 13 separately shows schematic diagrams of the structures of the first mass content and the second mass content. Specifically, the separator coating layer covering the intermediate region of the base separator 1041 contains an adhesive polymer with a low content, and the separator coating layer covering the edge region of the base separator 1041 contains an adhesive polymer with a high content.

[0153]

[0167] Optionally, the second mass content can be, for example, 0.4 g / m 2 to 5 g / m 2 It is possible to set it like this.

[0154]

[0168] In one example, the third type of separator coating layer 1044 has a mass content of 0.5 g / m2 It is possible to include an adhesive polymer. A method of forming a slurry of the third type of separator coating layer 1044 may include the following: the raw materials of the coating layer are obtained based on a mass ratio, in which case the polytetrafluoroethylene copolymer occupies 47.5 parts, deionized water occupies 50 parts, an aqueous wetting agent occupies 1.0 part, and an aqueous dispersing agent occupies 1.5 parts. Next, the polytetrafluoroethylene copolymer is added to the deionized water and rapidly dispersed with a high-speed disperser to obtain a slurry dispersion. In this case, the specific rotation speed may be, for example, 15000 r / min, and the dispersion time may be, for example, 2 h. Then, a completely dissolved aqueous dispersing agent and an aqueous wetting agent are added and sufficiently stirred and pulverized. In this case, the stirring and pulverizing time may be, for example, 3 h. Finally, vacuuming and defoaming are performed to obtain a uniformly mixed slurry of the third type of separator coating layer 1044.

[0155]

[0169] In another example, the third type of separator coating layer 1044 may include an adhesive polymer having a mass content of 0.62 g / m 2 It is possible to include an adhesive polymer. A method of forming a slurry of the third type of separator coating layer 1044 may include the following: the raw materials of the coating layer are obtained based on a mass ratio, in which case boehmite occupies 30 parts, deionized water occupies 46 parts, an adhesive occupies 13.5 parts, an aqueous wetting agent occupies 1.0 part, and an aqueous dispersing agent occupies 1.5 parts. Next, the boehmite is added to the deionized water and rapidly dispersed with a high-speed disperser to obtain a slurry dispersion. In this case, the specific rotation speed may be, for example, 15000 r / min, and the dispersion time may be, for example, 2 h. Then, a completely dissolved aqueous dispersing agent and an aqueous wetting agent are added and sufficiently stirred and pulverized. In this case, the stirring and pulverizing time may be, for example, 3 h. Finally, vacuuming and defoaming are performed to obtain a uniformly mixed slurry of the third type of separator coating layer 1044.

[0156] ​​

[0170] In yet another example, the third type of separator coating layer 1044 can include an adhesive polymer having a mass content of 0.62 g / m 2 The method of forming the slurry of the third type of separator coating layer 1044 can include the following: the raw materials of the coating layer are obtained based on a mass ratio, in which case, polyvinylidene fluoride - hexafluoropropylene occupies 51.5 parts, deionized water occupies 46 parts, an aqueous wetting agent occupies 1.0 part, and an aqueous dispersing agent occupies 1.5 parts. Next, polyvinylidene fluoride - hexafluoropropylene is added to deionized water and dispersed at high speed with a high - speed disperser to obtain a slurry dispersion. In this case, the specific rotation speed can be, for example, 15000 r / min, and the dispersion time can be, for example, 2 h. Then, the completely dissolved aqueous dispersing agent and aqueous wetting agent are added, and sufficient stirring and grinding are performed. In this case, the stirring and grinding time can be, for example, 3 h. Finally, evacuation and defoaming are carried out to obtain a uniformly mixed slurry of the third type of separator coating layer 1044.

[0157]

[0171] In yet another example, the third type of separator coating layer 1044 has a mass content of 0.45 g / m 2It is possible to include an adhesive polymer. A method for forming the slurry of the third type of separator coating layer 1044 may include the following: the raw materials of the coating layer are obtained based on mass ratio. In this case, the polyhexafluoropropylene copolymer occupies 52.0 parts, deionized water occupies 45.5 parts, an aqueous wetting agent occupies 1.0 part, and an aqueous dispersant occupies 1.5 parts. Next, the polyhexafluoropropylene copolymer is added to the deionized water and dispersed at high speed with a high-speed disperser to obtain a slurry dispersion. In this case, the specific rotation speed may be, for example, 15000 r / min, and the dispersion time may be, for example, 2 h. Then, the completely dissolved aqueous dispersant and aqueous wetting agent are added and stirred and pulverized sufficiently. In this case, the stirring and pulverizing time may be, for example, 3 h. Finally, evacuation and defoaming are performed to obtain a uniformly mixed slurry of the third type of separator coating layer 1044.

[0158]

[0172] Optionally, the second mass content may be, for example, 0.8 g / m 2 to 2.5 g / m 2 and may be.

[0159]

[0173] Optionally, the difference between the second mass content and the first mass content may be, for example, 0.05 g / m 2 to 4.5 g / m 2 and may be.

[0160]

[0174] Optionally, the difference between the second mass content and the first mass content may be, for example, 0.1 g / m 2 to 2.0 g / m 2 and may be.

[0161]

[0175] The adhesive polymer can include, for example, at least one of polyvinylidene fluoride, polyhexafluoropropylene, vinylidene fluoride - hexafluoropropylene copolymer, vinylidene fluoride - trichloroethylene copolymer, polyethylene - vinyl acetate copolymer, sodium carboxymethyl cellulose, styrene - butadiene rubber, polyacrylic acid, polyacrylate, polyacrylamide, polyacrylonitrile, polyamide, polyimide, polyethylene oxide, cellulose acetate, cellulose acetate butyrate, cellulose acetate propionate, polyvinylpyrrolidone, polyvinyl acetate, polyvinyl ether, polymethyl methacrylate, and polytetrafluoroethylene.

[0176] As shown in the partial enlarged view of FIG. 13, since the second - type separator coating layer 1043 and the third - type separator coating layer 1044 contain adhesive polymers with different mass contents, the thickness of the third - type separator coating layer 1044 may be slightly higher than the thickness of the second - type separator coating layer 1043. Specifically, the third - type separator coating layer 1044 may have a first thickness at the boundary position between the third - type separator coating layer 1044 and the second - type separator coating layer 1043, where the first thickness may be the same as the thickness of the second - type separator coating layer 1043; also, the third - type separator coating layer 1044 may have a second thickness at another position, where the second thickness is greater than the first thickness. This helps to improve the tightness of the bond between the separator and the electrode plate.

[0162]

[0177] In a particular scenario, the edges of the electrode plates may not adhere firmly to the second type of separator coating layer 1043. Since the third type of separator coating layer 1044 has more adhesive polymer, the third type of separator coating layer 1044 can be filled between the second type of separator coating layer 1043 and the electrode plates to further improve the tightness of the connection between the separator and the electrode plates.

[0163]

[0178] FIG. 14 is a schematic diagram of a mechanism for processing the battery 40 by using the hot press process according to an embodiment of the present application. The upper diagram of FIG. 14 (i.e., the diagram located above the arrow in FIG. 14) is a schematic diagram of the structure of the battery 40 before the hot press process. The lower diagram of FIG. 14 (i.e., the diagram located below the arrow in FIG. 14) is a schematic diagram of the structure of the battery 40 after the hot press process.

[0164]

[0179] The battery 40 can include the positive electrode plates 1011, 1012, the negative electrode plates 1021, 1022 stacked in this order. The positive electrode plates 1011 and 1012 may be two adjacent positive electrode plates. The negative electrode plates 1021 and 1022 may be two adjacent negative electrode plates. The negative electrode plate 1021 is between the positive electrode plates 1011 and 1012, and the positive electrode plate 1012 is between the negative electrode plates 1021 and 1022.

[0165]

[0180] The battery 40 can further include a base separator 10411, a base separator 10412, and a base separator 10413. The base separator 10411 can be positioned between the positive electrode plate 1011 and the negative electrode plate 1021. The base separator 10412 can be positioned between the negative electrode plate 1021 and the positive electrode plate 1012. The base separator 10413 can be positioned between the positive electrode plate 1012 and the negative electrode plate 1022. In other words, the base separator 10412 can be positioned between the base separator 10411 and the base separator 10413.

[0166]

[0181] The battery 40 can further include a second type of separator coating layer 10431, a second type of separator coating layer 10432, a third type of separator coating layer 10441, and a third type of separator coating layer 10442.

[0167]

[0182] The second type of separator coating layer 10431 is adhered to a side surface of the base separator 10411 that is away from the base separator 10412 and is adhered to an intermediate region of the base separator 10411. The third type of separator coating layer 10441 is adhered to a side surface of the base separator 10411 that is away from the base separator 10412 and is adhered to an edge region of the base separator 10411. The second type of separator coating layer 10432 is adhered to a side surface of the base separator 10411 that is close to the base separator 10412 and is adhered to an intermediate region of the base separator 10411. The third type of separator coating layer 10442 is adhered to a side surface of the base separator 10411 that is close to the base separator 10412 and is adhered to an edge region of the base separator 10411. The third type of separator coating layer 10441 and the third type of separator coating layer 10442 may be located on the same side of the base separator 10411.

[0168]

[0183] As shown in the upper figure of FIG. 14, before the hot press process, the third type of separator coating layer 10441 is adhered to the positive electrode plate 1011, and a specific gap may occur between the second type of separator coating layer 10431 and the positive electrode plate 1011. In the hot press process, the third type of separator coating layer 10441 can melt under the influence of high temperature and pressure and flow and spread on the base separator 1041. After the hot press process, both the third type of separator coating layer 10441 and the second type of separator coating layer 10431 can be adhered to the positive electrode plate 1011.

[0169]

[0184] As shown in the upper figure of FIG. 14, before the hot press process, the third type of separator coating layer 10442 is adhered to the negative electrode plate 1021, and a specific gap may occur between the second type of separator coating layer 10432 and the negative electrode plate 1021. In the hot press process, the third type of separator coating layer 10442 can melt under the influence of high temperature and pressure and flow and spread on the base separator 1041. After the hot press process, both the third type of separator coating layer 10442 and the second type of separator coating layer 10432 can be adhered to the negative electrode plate 1021.

[0170]

[0185] The battery 40 can further include a second type of separator coating layer 10433, a second type of separator coating layer 10434, a third type of separator coating layer 10443, and a third type of separator coating layer 10444. The second type of separator coating layer 10433 is adhered to the side surface of the base separator 10412 close to the base separator 10411 and is adhered to the middle region of the base separator 10412. The third type of separator coating layer 10443 is adhered to the side surface of the base separator 10412 close to the base separator 10411 and is adhered to the edge region of the base separator 10412. The second type of separator coating layer 10434 is adhered to the side surface of the base separator 10412 close to the base separator 10413 and is adhered to the middle region of the base separator 10412. The third type of separator coating layer 10444 is adhered to the side surface of the base separator 10412 close to the base separator 10413 and is adhered to the edge region of the base separator 10412. The third type of separator coating layer 10443 and the third type of separator coating layer 10444 may be located on the same side of the base separator 10412.

[0171]

[0186] As shown in the upper figure of FIG. 14, before the hot press process, the third type of separator coating layer 10443 is adhered to the negative electrode plate 1021, and there may be a specific gap between the second type of separator coating layer 10433 and the negative electrode plate 1021. In the hot press process, the third type of separator coating layer 10443 can melt under the influence of high temperature and pressure and flow and spread on the base separator 1041. After the hot press process, both the third type of separator coating layer 10443 and the second type of separator coating layer 10433 can be adhered to the negative electrode plate 1021.

[0172]

[0187] As shown in the upper figure of FIG. 14, before the hot press process, the third type of separator coating layer 10444 is adhered to the positive electrode plate 1012, and a specific gap may occur between the second type of separator coating layer 10434 and the positive electrode plate 1012. In the hot press process, the third type of separator coating layer 10444 can melt under the influence of high temperature and pressure and flow and spread on the base separator 1041. After the hot press process, both the third type of separator coating layer 10444 and the second type of separator coating layer 10434 can be adhered to the positive electrode plate 1012.

[0173]

[0188] The battery 40 can further include the second type of separator coating layer 10435, the second type of separator coating layer 10436, the third type of separator coating layer 10445, and the third type of separator coating layer 10446. The second type of separator coating layer 10435 is adhered to the side surface of the base separator 10413 that is close to the base separator 10412 and is adhered to the middle region of the base separator 10413. The third type of separator coating layer 10445 is adhered to the side surface of the base separator 10413 that is close to the base separator 10412 and is adhered to the edge region of the base separator 10413. The second type of separator coating layer 10436 is adhered to the side surface of the base separator 10413 that is far from the base separator 10412 and is adhered to the middle region of the base separator 10413. The third type of separator coating layer 10446 is adhered to the side surface of the base separator 10413 that is far from the base separator 10412 and is adhered to the edge region of the base separator 10413. The third type of separator coating layer 10445 and the third type of separator coating layer 10446 may be located on the same side of the base separator 10412.

[0174]

[0189] As shown in the upper figure of FIG. 14, before the hot press process, the third type of separator coating layer 10445 is adhered to the positive electrode plate 1012, and a specific gap may occur between the second type of separator coating layer 10435 and the positive electrode plate 1012. In the hot press process, the third type of separator coating layer 10445 can melt under the influence of high temperature and pressure and flow and spread over the base separator 1041. After the hot press process, both the third type of separator coating layer 10445 and the second type of separator coating layer 10435 can be adhered to the positive electrode plate 1012.

[0175]

[0190] As shown in the upper figure of FIG. 14, before the hot press process, the third type of separator coating layer 10446 is adhered to the negative electrode plate 1022, and a specific gap may occur between the second type of separator coating layer 10436 and the negative electrode plate 1022. In the hot press process, the third type of separator coating layer 10446 can melt under the influence of high temperature and pressure and flow and spread over the base separator 1041. After the hot press process, both the third type of separator coating layer 10446 and the second type of separator coating layer 10436 can be adhered to the negative electrode plate 1022.

[0176]

[0191] Optionally, the widths of the third type of separator coating layer 10441, the third type of separator coating layer 10442, the third type of separator coating layer 10443, the third type of separator coating layer 10444, the third type of separator coating layer 10445, and the third type of separator coating layer 10445 can be 0.1% to 45% of the width of the electrode plate.

[0177]

[0192] As an option, the widths of the third type of separator coating layers 10441, 10442, 10443, 10444, 10445, and 10445 can be set to 0.5% to 5.0% of the width of the electrode plate.

[0178]

[0193] In conclusion, before the hot press process, the separator corresponding to the middle region of the electrode plate can include a base separator and a second type of separator coating layer, and the separator corresponding to the edge region of the electrode plate can include a base separator and a third type of separator coating layer. The thickness of the second type of separator coating layer may be thinner than the (minimum) thickness of the third type of separator coating layer, and the thickness of the separator corresponding to the middle region of the electrode plate may be thinner than the thickness of the separator corresponding to the edge region of the electrode plate. After the hot press process, the adhesive polymer undergoes physical changes such as heat melting or cross-linking, and the adhesive polymer can be completely filled between the base separator and the electrode plate, thereby reducing the risk of lithium ion precipitation.

[0179]

[0194] Also, an adhesive polymer with a high mass content is disposed in the edge region of the base separator, which helps to improve the bonding ability of the base separator in the edge region and also helps to improve the bonding force between the electrode plate and the separator, thereby improving the cycle performance of the battery and helping to improve cell deformation. Furthermore, due to different contents, the adhesive polymer in the edge region may have a higher thickness, which helps to improve the overall hot press uniformity of the electrode.

[0180]

[0195] FIG. 15 is a schematic diagram of another structure of the battery 40 according to an embodiment of the present application. Referring to the examples shown in FIGS. 6, 13, and 15, it can be seen that after the hot press process, the adjacent third type of separator coating layers 1044 arranged face to face may be fused together to form the first type of separator coating layer 1042 shown in FIG. 15. Referring to the examples shown in FIGS. 13 and 15, the mass content of the adhesive polymer contained in the first type of separator coating layer 1042 may be greater than the mass content of the adhesive polymer contained in the second type of separator coating layer 1043, and the first type of separator coating layer 1042 may be connected between two adjacent base separators 1041 so as to surround the electrode plate located between two adjacent substrates. This helps to reduce the possibility of a short circuit occurring between the adjacent positive electrode plate 101 and negative electrode plate 102.

[0181]

[0196] To explain the technical effects of the solutions provided in the present application, several embodiments are compared below.

[0182]

[0197] Embodiment 1 Embodiment 1 may be applied to a laminated pouch cell 50110227 having a capacity of 10.8 Ah and an operating voltage range of 2.75 V to 4.30 V (height is 50 mm, width is 110 mm, and length is 227 mm).

[0183]

[0198] The battery includes a conventional base separator, and the separator coating layer is uniformly coated on two planes of the base separator, where the separator coating layer has adhesiveness. In other words, the content of the adhesive polymer in the middle region of the separator coating layer is approximately equal to the content of the adhesive polymer in the edge region of the separator coating layer. The mass content of the adhesive polymer is 0.1 g / m 2 is.

[0184]

[0199] Embodiment 2 Embodiment 2 may be applied to a wound pouch cell 506390 having a capacity of 5 Ah and an operating voltage range of 3.0 V to 4.48 V (height: 50 mm, width: 63 mm, length: 90 mm).

[0185]

[0200] The battery includes a base separator with a thickness of 5.5 μm and a polyethylene material, and the porosity of the base separator is 39.0%. The battery further includes a separator coating layer adhered to the edge region of the base separator (the adhesive separator coating layer is not adhered to the middle region of the base separator). The separator coating layer contains an adhesive polymer with a mass content of 0.5 g / m 2 . The separator coating layer may be coated on both sides of the base separator in the machine direction TD. The width of the separator coating layer may be 3 mm. The separator coating layer may correspond to the first type of separator coating layer described in FIGS. 4 to 12.

[0186]

[0201] Embodiment 3 Embodiment 3 may be applied to a laminated pouch cell 50110227 having a capacity of 10.8 Ah and an operating voltage range of 2.75 V to 4.30 V (height: 50 mm, width: 110 mm, length: 227 mm).

[0187]

[0202] The battery includes a base separator with a thickness of 7.0 μm and a polyethylene material, and the porosity of the base separator is 38.6%. The battery further includes a separator coating layer adhered to the edge region of the base separator (the adhesive separator coating layer is not adhered to the middle region of the base separator). The separator coating layer may be coated on both sides of the base separator in the machine direction MD and the transverse direction TD. The width of the separator coating layer may be 2 mm. The separator coating layer includes an adhesive polymer and a ceramic coating layer, and the ratio of the adhesive polymer to the ceramic coating layer is 5:5. The separator coating layer has a mass content of 0.62 g / m 2 and includes an adhesive polymer. The separator coating layer has a mass content of 0.62 g / m 2 and includes a ceramic coating layer. The separator coating layer may correspond to the first type of separator coating layer described in FIGS. 4 to 12.

[0188]

[0203] Embodiment 4 Embodiment 4 may be applied to a wound pouch cell 506390 having a capacity of 5 Ah and an operating voltage range of 3.0 V to 4.48 V (with a height of 50 mm, a width of 63 mm, and a length of 90 mm).

[0189]

[0204] The battery includes a base separator with a thickness of 5.5 μm and a polyethylene material, and the porosity of the base separator is 39.0%. The battery further includes a separator coating layer 1 adhered to the edge region of the base separator and a separator coating layer 2 adhered to the middle region of the base separator. Both the separator coating layer 1 and the separator coating layer 2 may be coated on both sides of the base separator in the machine direction TD. The width of the separator coating layer 1 may be 3 mm. Both the separator coating layer 1 and the separator coating layer 2 include an adhesive polymer. In the separator coating layer 1, the mass content of the adhesive polymer is 0.6 g / m 2 . In the separator coating layer 2, the mass content of the adhesive polymer is 0.1 g / m 2 . The separator coating layer 1 may correspond to the third type of separator coating layer described in FIGS. 13 and 14 and the first type of separator coating layer described in FIG. 15. The separator coating layer 2 may correspond to the second type of separator coating layer described in FIGS. 13 to 15.

[0190]

[0205] Embodiment 5 Embodiment 5 may be applied to a wound pouch cell 50110227 having a capacity of 10.8 Ah and an operating voltage range of 2.75 V to 4.30 V (height is 50 mm, width is 110 mm, and length is 227 mm).

[0191]

[0206] The battery includes a base separator with a thickness of 7.0 μm and a polyethylene material, and the porosity of the base separator is 38.6%. The battery further includes a separator coating layer 1 adhered to the edge region of the base separator and a separator coating layer 2 adhered to the middle region of the base separator. Both the separator coating layer 1 and the separator coating layer 2 may be coated on both sides of the base separator in the machine direction TD. The width of the separator coating layer 1 may be 2 mm. Both the separator coating layer 1 and the separator coating layer 2 contain an adhesive polymer. In the separator coating layer 1, the mass content of the adhesive polymer is 0.62 g / m 2 is. The separator coating layer 2 further includes a ceramic coating layer, and the ratio of the ceramic coating layer to the adhesive polymer is 5:5. In the separator coating layer 2, the total mass content of the ceramic coating layer and the adhesive polymer is 0.62 g / m 2 is. The separator coating layer 1 may correspond to a third type of separator coating layer described in FIGS. 13 and 14 and a first type of separator coating layer described in FIG. 15. The separator coating layer 2 may correspond to a second type of separator coating layer described in FIGS. 13 to 15.

[0192]

[0207] The raw materials of the separator coating layer 2 may include, for example, 25 parts of boehmite, 25 parts of polyvinylidene fluoride - hexafluoropropylene, 46 parts of deionized water, 3.5 parts of an adhesive, 1.0 part of an aqueous wetting agent, and 1.5 parts of an aqueous dispersant. Next, the boehmite is added to the deionized water and dispersed at high speed with a high - speed disperser to obtain a slurry dispersion. In this case, the specific rotation speed may be, for example, 15000 r / min, and the dispersion time may be, for example, 2 h. Then, the completely dissolved polyvinylidene fluoride - hexafluoropropylene, deionized water, adhesive, aqueous wetting agent, and aqueous dispersant are added, and they are sufficiently stirred and pulverized. In this case, the stirring and pulverizing time may be, for example, 3 h. Finally, vacuuming and defoaming are performed to obtain a uniformly mixed slurry of the third - type separator coating layer.

[0193]

[0208] Embodiment 6 Embodiment 6 may be applied to a wound - type pouch cell 454378 having a capacity of 2.8 Ah and an operating voltage range of 3.0 V to 4.48 V (height is 45 mm, width is 43 mm, and length is 78 mm).

[0194]

[0209] The battery includes a base separator with a thickness of 7.0 μm and a polypropylene material, and the porosity of the base separator is 37.7%.

[0195]

[0210] The battery further includes a ceramic coating layer adhered to a single surface, a separator coating layer 1 adhered to the edge region of the base separator, and a separator coating layer 2 adhered to the middle region of the base separator. Both the separator coating layer 1 and the separator coating layer 2 may be coated on both sides of the base separator in the machine direction TD. The width of the separator coating layer 1 may be 2 mm. Both the separator coating layer 1 and the separator coating layer 2 include an adhesive polymer. In the separator coating layer 1, the mass content of the adhesive polymer is 0.95 g / m 2 is. In the separator coating layer 2, the mass content of the adhesive polymer is 0.5 g / m 2 is. The separator coating layer 1 may correspond to the third type of separator coating layer described in FIGS. 13 and 14 and the first type of separator coating layer described in FIG. 15. The separator coating layer 2 may correspond to the second type of separator coating layer described in FIGS. 13 to 15.

[0196]

[0211] The raw materials of the ceramic coating layer may include, for example, 50 parts of boehmite, 45.5 parts of deionized water, 1.0 part of carboxymethyl cellulose, and 3.5 parts of styrene butadiene rubber. Next, boehmite is added to deionized water and dispersed at high speed with a high-speed disperser to obtain a slurry dispersion. In this case, the specific rotation speed may be, for example, 15000 r / min, and the dispersion time may be, for example, 2 h. Then, completely dissolved carboxymethyl cellulose and styrene butadiene rubber are added, and stirred and pulverized sufficiently. In this case, the stirring and pulverizing time may be, for example, 3 h. Finally, evacuation and defoaming are performed to obtain a uniformly mixed slurry of the third type of separator coating layer.

[0197]

[0212] Embodiment 7 Embodiment 7 can be applied to a wound pouch cell 455382 having a capacity of 3.6 Ah and an operating voltage range of 3.0 V to 4.48 V (height: 45 mm, width: 53 mm, length: 82 mm).

[0198]

[0213] The battery includes a base separator with a thickness of 4.5 μm and a polyethylene material, and the porosity of the base separator is 38.5%. The battery further includes a separator coating layer 1 adhered to the edge region of the base separator and a separator coating layer 2 adhered to the middle region of the base separator. Both the separator coating layer 1 and the separator coating layer 2 may be coated on both sides of the base separator in the machine direction TD. The width of the separator coating layer 1 may be 1.5 mm. Both the separator coating layer 1 and the separator coating layer 2 include an adhesive polymer and a ceramic coating layer. In the separator coating layer 1, the ratio of the adhesive polymer to the ceramic coating layer is 7:3. In the separator coating layer 2, the ratio of the adhesive polymer to the ceramic coating layer is 5:5. The mass content of the separator coating layer on one side is 0.43 g / m 2 ². The separator coating layer 1 may correspond to the third type of separator coating layer described in FIGS. 13 and 14 and the first type of separator coating layer described in FIG. 15. The separator coating layer 2 may correspond to the second type of separator coating layer described in FIGS. 13 to 15.

[0199]

[0214] For example, the method of forming the slurry of the separator coating layer 1 may include the following: the raw materials of the coating layer are obtained based on the mass ratio. In this case, boehmite occupies 13.5 parts, deionized water occupies 46 parts, the adhesive occupies 32.5 parts, the binder occupies 5 parts, the aqueous wetting agent occupies 1.0 part, and the aqueous dispersant occupies 1.5 parts. Next, boehmite is added to deionized water and dispersed at high speed with a high-speed disperser to obtain a slurry dispersion. In this case, the specific rotation speed may be, for example, 15000 r / min, and the dispersion time may be, for example, 2 h. Then, the completely dissolved aqueous dispersant, aqueous wetting agent, and PVDF powder are added and stirred and pulverized sufficiently. In this case, the stirring and pulverizing time may be, for example, 3 h. Finally, vacuumization and defoaming are performed to obtain a uniformly mixed slurry of the third type of separator coating layer.

[0200]

[0215] The method of forming the slurry of the separator coating layer 2 may include the following: the raw materials of the coating layer are obtained based on the mass ratio. In this case, boehmite occupies 23.5 parts, the adhesive occupies 23.5 parts, deionized water occupies 46 parts, the aqueous wetting agent occupies 1.0 part, and the aqueous dispersant occupies 1.5 parts. Next, boehmite is added to deionized water and dispersed at high speed with a high-speed disperser to obtain a slurry dispersion. In this case, the specific rotation speed may be, for example, 15000 r / min, and the dispersion time may be, for example, 2 h. Then, the completely dissolved aqueous dispersant, aqueous wetting agent, and PVDF powder are added and stirred and pulverized sufficiently. In this case, the stirring and pulverizing time may be, for example, 3 h. Finally, vacuumization and defoaming are performed to obtain a uniformly mixed slurry of the third type of separator coating layer. The separator coating layer 1 may correspond to the third type of separator coating layer described in FIGS. 13 and 14 and the first type of separator coating layer described in FIG. 15. The separator coating layer 2 may correspond to the second type of separator coating layer described in FIGS. 13 to 15.

[0201]

[0216] Embodiment 8 Embodiment 8 can be applied to a wound pouch cell 466082 having a capacity of 4.2 Ah and an operating voltage range of 3.0 V to 4.48 V (height: 46 mm, width: 60 mm, length: 82 mm).

[0202]

[0217] The battery includes a base separator with a thickness of 4.5 μm and a polyethylene material, and the porosity of the base separator is 40.0%. The battery further includes a separator coating layer 1 adhered to the edge region of the base separator and a separator coating layer 2 adhered to the middle region of the base separator. Both the separator coating layer 1 and the separator coating layer 2 may be coated on both sides of the base separator in the machine direction TD. The width of the separator coating layer 1 may be 1.5 mm. Both the separator coating layer 1 and the separator coating layer 2 contain an adhesive polymer, and the separator coating layer 2 further contains a ceramic coating layer. In the separator coating layer 2, the ratio of the adhesive polymer to the ceramic coating layer is 6:4. The mass content of the separator coating layer on one side is 0.54 g / m 2 2. The separator coating layer 1 may correspond to the third type of separator coating layer described in FIGS. 13 and 14 and the first type of separator coating layer described in FIG. 15. The separator coating layer 2 may correspond to the second type of separator coating layer described in FIGS. 13 to 15.

[0203]

[0218] For example, the method of forming the slurry of the separator coating layer 1 may include the following: the raw materials of the coating layer are obtained based on the mass ratio. In this case, boehmite occupies 30.9 parts, deionized water occupies 46 parts, the adhesive occupies 20.6 parts, the aqueous wetting agent occupies 1.0 part, and the aqueous dispersant occupies 1.5 parts. Next, boehmite is added to deionized water and dispersed at high speed with a high-speed disperser to obtain a slurry dispersion. In this case, the approximate rotation speed may be, for example, 15000 r / min, and the dispersion time may be, for example, 2 h. Then, the completely dissolved aqueous dispersant, aqueous wetting agent, and PVDF powder are added and stirred and pulverized sufficiently. In this case, the stirring and pulverizing time may be, for example, 3 h. Finally, evacuation and defoaming are performed to obtain a uniformly mixed slurry of the third type of separator coating layer.

[0204]

[0219] The method of forming the slurry of the separator coating layer 2 may include the following: the raw materials of the coating layer are obtained based on the mass ratio. In this case, polyvinylidene fluoride - hexafluoropropylene occupies 51.5 parts, deionized water occupies 46 parts, the aqueous wetting agent occupies 1.0 part, and the aqueous dispersant occupies 1.5 parts. Next, boehmite is added to deionized water and dispersed at high speed with a high-speed disperser to obtain a slurry dispersion. In this case, the specific rotation speed may be, for example, 15000 r / min, and the dispersion time may be, for example, 2 h. Then, the completely dissolved aqueous dispersant, aqueous wetting agent, and PVDF powder are added and stirred and pulverized sufficiently. In this case, the stirring and pulverizing time may be, for example, 3 h. Finally, evacuation and defoaming are performed to obtain a uniformly mixed slurry of the third type of separator coating layer.

[0205]

[0220] To compare the technical effects of the above embodiments, several methods for testing battery performance are shown below.

[0206]

[0221] Energy density test method:

[0222] The battery is placed in a thermostat at 25°C and left stationary for 30 minutes, and the battery is charged in the standard charging mode. After the battery is fully charged, the battery is discharged to the lower limit voltage based on the 0.2 C discharge specification, and the discharge energy of the battery is recorded. The energy density of the battery can be calculated according to the following formula: Energy density = Discharge energy / (Battery length * Battery width * Battery thickness)

[0223] Nail penetration test method:

[0224] After the battery is fully charged in the standard charging mode, the nail penetration test is performed on the battery at 12h to 24h. For example, the battery is placed in an explosion-proof box at 25°C, and a steel nail is penetrated through the center of the cell at a speed of 150 mm / s. The steel nail is stabbed towards the center of the battery at a speed of 150mm / s until the steel nail penetrates the battery. The steel nail is removed after being held for 10 minutes, and the test pass rate is recorded. The nail penetration test method can reflect the performance of the battery in a mechanical abuse scenario.

[0207]

[0225] Hot box test method:

[0226] After the battery is fully charged in the standard charging mode, the hot box test is performed on the battery at 12h to 24h. For example, a convection hot air box or a circulating hot air box is used to heat the battery from the initial temperature (25±3)°C to a temperature rise to (135±2)°C or (150±2)°C, where the temperature change rate is (5±2)°C / min. After the temperature reaches (135±2)°C or (150±2)°C, the temperature is held for 30 minutes, and the test pass rate is recorded. The hot box test can reflect the performance of the battery in a thermal abuse scenario.

[0208]

[0227] After the test, the battery is disassembled in a drying chamber, the width and length of the separator are tested, and the tested values are compared with the initial values and given.

[0209]

[0228] The test results of the above embodiments are shown in Table 1 and Table 2.

[0210] Table 1

[0211]

Table 1

[0212]

Table 2

[0229] It can be seen from the test results that the solutions provided in the embodiments of the present application help to improve the passing rates of the 100% SOC nail penetration test and the 150°C / 30-minute hot box test.

[0213]

[0230] Also, compared with Embodiment 2, the separator coating layer containing the adhesive polymer is arranged in both the edge region and the middle region, which helps to improve the adhesion performance in the middle region, improve the dynamic performance of the battery, and reduce the possibility of cell deformation. Also, the adhesive polymer is further helpful in forming pores, and the formation of pores increases the residual electrolyte, thus helping to improve the cycle performance of the battery and reduce the growth rate of the battery thickness. For example, after 300 cycles, the growth rate of the battery thickness is 4.8% or less.

[0214]

[0231] The above description is only a specific implementation of the present application and is not intended to limit the protection scope of the present application. Any deformation or substitution that can be easily grasped by those skilled in the art within the technical scope disclosed in the present application shall be included within the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A battery comprising: A first electrode plate; A first base separator and a second base separator, wherein the first base separator and the second base separator are two base separators adjacent to the first electrode plate, and the first base separator and the second base separator are respectively disposed on two sides of the first electrode plate; A first type of separator coating layer, wherein the first type of separator coating layer is adhered to a first edge region of the first base separator and a second edge region of the second base separator, the first edge region and the second edge region are located on the same side of the battery, and the first edge region and the second edge region are opposite to each other; and A second type of separator coating layer; The second type of separator coating layer is adhered to an intermediate region of the first base separator, the first type of separator coating layer is connected to the second type of separator coating layer, the second type of separator coating layer includes an adhesive polymer having a first mass content, the first type of separator coating layer includes an adhesive polymer having a second mass content, and the second mass content is greater than the first mass content.

2. The battery according to claim 1, wherein the first type of separator coating layer is also adhered to a side edge of the first electrode plate.

3. In the battery according to claim 1 or 2, the battery further includes a second electrode plate and a third base separator; both the second base separator and the third base separator are adjacent to the second electrode plate; the second base separator is located between the first base separator and the third base separator; the first type of separator coating layer is further adhered to a third edge region of the second base separator, a side edge of the second base separator, and a fourth edge region of the third base separator; the side edge of the second base separator connects the second edge region and the third edge region; the third edge region and the fourth edge region are arranged opposite to each other and are located on the same side of the battery. Battery.

4. In the battery according to claim 1 or 2, the battery further includes a third electrode plate, a fourth base separator, and a fifth base separator; both the fourth base separator and the fifth base separator are adjacent to the third electrode plate; the second base separator is located between the first base separator and the fourth base separator, and the fourth base separator is located between the second base separator and the fifth base separator; the first type of separator coating layer is further adhered to a side edge of the second base separator, a side edge of the fourth base separator, a fifth edge region of the fourth base separator, and a sixth edge region of the fifth base separator; the second edge region, the side edge of the second base separator, the side edge of the fourth base separator, the fifth edge region, and the sixth edge region are all on the same side of the battery; the fifth edge region and the sixth edge region are arranged opposite to each other. Battery.

5. In the battery according to claim 1, the second mass content rate is between 0.4 g / m 2 to 5 g / m 2 The battery is in between.

6. In the battery according to claim 1, the difference between the first mass content rate and the second mass content rate is between 0.05 g / m 2 to 4.5 g / m 2 The battery is in between.

7. In the battery according to any one of claims 1 to 6, the adhesive polymer is: polyvinylidene fluoride, polyhexafluoropropylene, vinylidene fluoride - hexafluoropropylene copolymer, vinylidene fluoride - trichloroethylene copolymer, polyethylene - vinyl acetate copolymer, sodium carboxymethyl cellulose, styrene - butadiene rubber, polyacrylic acid, polyacrylate, polyacrylate, polyacrylonitrile, polyamide, polyimide, polyethylene oxide, cellulose acetate, cellulose acetate butyrate, cellulose acetate propionate, polyvinylpyrrolidone, polyvinyl acetate, polyvinyl ether, polymethyl methacrylate, and at least one of polytetrafluoroethylene, battery.

8. In the battery according to claim 1, the battery further comprises an electrolyte, the solubility parameter of the first type of separator coating layer is the first solubility parameter, the solubility parameter of the electrolyte is the second solubility parameter, the first solubility parameter is less than or equal to the second solubility parameter, and the difference between the second solubility parameter and the first solubility parameter is less than or equal to a preset solubility parameter, battery.

9. In the battery according to claim 8, the pre-set solubility parameter is 5 (J / cm 3 ) 0.5 or less. Battery.

10. In the battery according to any one of claims 1 to 9, the width of the first type of separator coating layer is between 0.1% and 45% of the width of the first electrode plate, battery.

11. An electronic device comprising the battery according to any one of claims 1 to 10.

12. A mobile device comprising the battery according to any one of claims 1 to 10.

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