An electrode tab for improving the furnace temperature pass rate of an electrode and a battery comprising the same

Abstract

The application provides a tab for improving the furnace temperature passing rate of an electric core and a battery comprising the tab. The application utilizes the electric conduction and non-heat conduction phenomenon of a crystal material, fully utilizes the heat insulation property of the crystal material, can improve the electric conductivity of the tab, insulates the path of the external heat absorption and conduction of the tab to the inside of the electric core, insulates the heat conducted to the inside of the electric core by the tab at the edge of the heat insulation coating of the tab, protects the separator at the tab from being continuously baked by the external heat source to cause the thermal contraction of the separator and further cause the short circuit of the positive and negative tabs, reduces the internal thermal disorder failure caused by the thermal contraction of the separator, and improves the passing rate of the electric core in the furnace temperature test.

Description

Technical Field

[0001] This invention belongs to the field of battery technology, specifically relating to an electrode sheet for improving the furnace temperature pass rate of battery cells and a battery including the electrode sheet. Background Technology

[0002] With the widespread adoption of lithium-ion batteries, current batteries need to meet the requirements of high energy density and fast charging capability, meaning they need to achieve a charge level of over 80% in 15 minutes. Solutions to this fast charging requirement include using a centrally located tab structure or a multi-tab structure (such as...). Figure 1 (As shown in the diagram, a half-tab or full-tab structure). However, in this case, the furnace temperature pass rate of batteries with multi-tab structures is relatively low, which makes it impossible to guarantee their safety performance, severely restricting the application and promotion of lithium-ion batteries. Summary of the Invention

[0003] To address the shortcomings of existing technologies, this invention provides an electrode sheet for improving the furnace temperature pass rate of battery cells and a battery including the electrode sheet. Research has found that existing tabs (aluminum or nickel tabs) are excellent thermal conductors, effectively transferring heat to the inside of the battery cell. This causes the temperature at the tabs inside the cell to rise, reaching or even exceeding the glass transition temperature of the separator. This results in significant thermal shrinkage of the separator near the tabs, leading to direct contact between the positive and negative electrodes at the exposed areas and causing short-circuit discharge. Continuous heat release further decomposes the SEI film and electrolyte inside the cell, generating heat and ultimately leading to thermal runaway. This results in extremely low furnace temperature (thermal abuse) pass rates or complete failure for multi-tab batteries.

[0004] This invention introduces a heat-insulating coating into the electrode sheet. This coating improves the conductivity of the electrode sheet and isolates the path of heat absorption by the tabs and conduction into the cell. The heat conducted from the tabs to the cell is contained at the edge of the heat-insulating coating, protecting the separator at the tabs from continuous baking by external heat sources, which could lead to separator thermal shrinkage and short circuit between the positive and negative electrodes. This reduces internal thermal disturbance failure caused by separator thermal shrinkage and improves the cell's pass rate in furnace temperature testing.

[0005] The objective of this invention is achieved through the following technical solution:

[0006] An electrode sheet is provided, comprising a current collector, an active material layer, and a heat-insulating coating; the current collector comprises a first region, a second region, and a third region arranged sequentially along the width direction of the current collector; wherein the heat-insulating coating is disposed on the second region, and the active material layer is disposed on the third region.

[0007] According to an embodiment of the present invention, the current collector includes a first region, a second region, and a third region that are sequentially connected along the width direction of the current collector.

[0008] According to an embodiment of the present invention, the electrode is a positive electrode or a negative electrode.

[0009] According to an embodiment of the present invention, the current collector is a positive current collector or a negative current collector.

[0010] According to an embodiment of the present invention, the positive current collector is at least one of aluminum foil, porous aluminum foil, carbon-coated aluminum foil, etc.

[0011] According to an embodiment of the present invention, the negative electrode current collector is at least one of copper foil, porous copper foil, carbon-coated copper foil, etc.

[0012] According to an embodiment of the present invention, the heat-insulating coating comprises a crystalline material, a binder, and a conductive agent, wherein the chemical formula of the crystalline material is TlSb3Co.

[0013] According to an embodiment of the present invention, the mass percentage of each component in the heat insulation coating is: 94wt% to 99.8wt% of crystalline material, 0.1wt% to 3wt% of binder, and 0.1wt% to 3wt% of conductive agent.

[0014] According to an embodiment of the present invention, the mass percentage of each component in the heat insulation coating is: 94wt% to 98wt% of crystalline material, 1wt% to 3wt% of binder, and 1wt% to 3wt% of conductive agent.

[0015] According to an embodiment of the present invention, the crystalline material TlSb3Co has a melting point of 750°C and a density of 8.2 g / cm³. 3 The molecular weight of the crystal material TlSb3Co is 628, and the Mohs hardness of the crystal material TlSb3Co is 2.5.

[0016] According to an embodiment of the present invention, the crystal structure of the crystal material TlSb3Co is as follows: Figure 4 As shown.

[0017] According to an embodiment of the present invention, the crystal material TlSb3Co can be prepared by methods known in the art, or it can be obtained through commercial purchase.

[0018] According to an embodiment of the present invention, the crystal material TlSb3Co has a framework structure built from "cages" composed of cobalt atoms and antimony atoms, and each "cage" is filled with a single thallium atom.

[0019] According to embodiments of the present invention, the thermal conductivity of conventional materials originates from the uniform vibration of atoms. However, the crystalline material TlSb3Co of the present invention has a "framework structure" built from "cages" of cobalt and antimony atoms. This means that when the entire crystalline material is heated, the thallium atoms can only vibrate randomly in their possible directions, rather than forming a uniform array of oscillations, thus preventing heat transfer. However, the current conduction process mainly relies on the flow of metal electrons and is therefore unaffected. Therefore, the crystalline material TlSb3Co of the present invention has the function of conducting electricity but not heat, preventing the external heat source from being continuously conducted to the inside of the cell at the electrode tabs, thus preventing continuous heating of the separator inside the cell. This ensures that the separator at the electrode tabs is not damaged or the degree of damage is greatly reduced, minimizing the risk of short circuits between the positive and negative electrodes, and thereby improving the cell furnace temperature throughput. Furthermore, the heat-insulating coating can increase the cross-sectional area of ​​the conductor, increasing the current carrying capacity (i.e., instantaneous current), making the cell's heating effect less significant, and further improving the battery's safety performance.

[0020] According to an embodiment of the present invention, no coating is applied to the first region.

[0021] According to an embodiment of the present invention, the first region is a reserved region for forming a tab.

[0022] According to an embodiment of the present invention, the first region is used to form a multi-pole ear; exemplarily, it is used to form a full-pole ear structure or a half-pole ear structure.

[0023] According to an embodiment of the present invention, the semi-tab structure is formed by stamping a first region to form multiple tabs, ensuring that each turn of the electrode sheet forms a tab after winding; the full tab structure is formed by stamping a first region to form multiple tabs, ensuring that each fold of the electrode sheet forms a tab after winding.

[0024] According to embodiments of the present invention, the full-tip structure and the half-tip structure are as follows: Figure 1 As shown.

[0025] According to an embodiment of the present invention, the width of the first region is 10mm to 30mm, for example, 10mm, 16mm, 18mm, 20mm, 22mm, 24mm, 25mm, 28mm or 30mm.

[0026] According to an embodiment of the present invention, the width of the second region is 0.5mm to 5mm, for example, 0.5mm, 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm or 5mm.

[0027] According to an embodiment of the present invention, the width of the third region is 50 mm to 100 mm, for example, 50 mm, 55 mm, 60 mm, 65 mm, 70 mm, 75 mm, 80 mm, 85 mm, 90 mm, 95 mm or 100 mm.

[0028] According to an embodiment of the present invention, the thickness of the active material layer is the same as that of the thermal insulation coating.

[0029] According to an embodiment of the present invention, the active material layer includes an active material, a binder, and a conductive agent.

[0030] According to an embodiment of the present invention, the mass percentage content of each component in the active material layer is: 80 to 99.8 wt% of the active material, 0.1 to 10 wt% of the conductive agent, and 0.1 to 10 wt% of the binder.

[0031] Preferably, the mass percentage content of each component in the active material layer is: 90 to 99.6 wt% of the active material, 0.2 to 5 wt% of the conductive agent, and 0.2 to 5 wt% of the binder.

[0032] According to an embodiment of the present invention, the conductive agent is selected from at least one of conductive carbon black, acetylene black, Ketjen black, conductive graphite, conductive carbon fiber, carbon nanotube, metal powder, and carbon fiber.

[0033] According to an embodiment of the present invention, the binder is selected from at least one of sodium carboxymethyl cellulose, styrene-butadiene latex, polytetrafluoroethylene, and polyethylene oxide.

[0034] According to an embodiment of the present invention, the active material is a positive electrode active material or a negative electrode active material.

[0035] According to an embodiment of the present invention, the negative electrode active material is selected from at least one of artificial graphite, natural graphite, mesocarbon microbeads, hard carbon, soft carbon, lithium-containing metal composite oxide material, silicon-oxygen negative electrode material (SiOx (0 < x < 2)), and silicon-carbon negative electrode material.

[0036] According to an embodiment of the present invention, the positive electrode active material is selected from at least one of lithium manganate, lithium iron phosphate, nickel cobalt manganese lithium ternary material, nickel manganese lithium, and lithium-rich manganese-based material.

[0037] The present invention also provides a battery, and the battery includes the above-mentioned electrode sheet.

[0038] Advantages of the present invention:

[0039] This invention provides an electrode sheet for improving the furnace temperature pass rate of a battery cell and a battery including the electrode sheet. This invention utilizes the electrical conductivity but thermal insulation properties of crystalline materials, fully leveraging their thermal insulation properties. It improves the conductivity of the electrode sheet and isolates the path of heat absorption by the tabs and conduction into the battery cell. This prevents heat conducted from the tabs to the battery cell from reaching the edge of the electrode sheet's heat-insulating coating, protecting the separator at the tabs from continuous external heat source exposure and preventing thermal shrinkage that could lead to short circuits between the positive and negative electrodes. This reduces internal thermal disturbances and failures caused by separator thermal shrinkage, thereby improving the battery cell's pass rate in furnace temperature testing. Attached Figure Description

[0040] Figure 1 : A schematic diagram of the structure of an electrode sheet with half-tabs and full-tabs in the prior art.

[0041] Figure 2 : A schematic diagram of the structure of the electrode sheet according to a preferred embodiment of the present invention.

[0042] Figure 3 : A schematic diagram of the structure of an electrode in the prior art.

[0043] Figure 4 The crystal structure of the crystal material TlSb3Co of the present invention.

[0044] The attached diagram is labeled as follows: 1 represents the first region, 2 represents the second region, 3 represents the third region, 4 represents the fourth region, and 5 represents the fifth region. Detailed Implementation

[0045] The present invention will be further described in detail below with reference to specific embodiments. It should be understood that the following embodiments are merely illustrative and explanatory of the present invention and should not be construed as limiting the scope of protection of the present invention. All technologies implemented based on the above content of the present invention are covered within the scope of protection intended by the present invention.

[0046] Unless otherwise specified, the experimental methods used in the following examples are conventional methods; unless otherwise specified, the reagents and materials used in the following examples are commercially available.

[0047] In the description of this invention, it should be noted that the terms "first," "second," and "third," etc., are used for descriptive purposes only and are not intended to indicate or imply relative importance.

[0048] The term "thermally conductive but non-conductive" means that the material can conduct electricity normally under normal use, but can isolate the heat source from the outside of the coating during heat transfer, reducing or isolating the heat source and protecting the internal components, so that the internal components can maintain their good shape at a certain temperature (such as 130°C or higher).

[0049] The performance testing process for the following batteries is as follows:

[0050] Furnace temperature test under full charge: The battery is charged at a constant current rate of 0.7C in a 25°C constant temperature chamber. When the voltage reaches the cutoff voltage, the charging regime switches to constant voltage mode, continuing charging until the current cutoff at 0.02C. After charging, the battery is heated from room temperature (25°C) to a specified temperature (130°C / 135°C) at a rate of 5°C / min and held at that temperature for 60 minutes. After the time is up, the constant temperature chamber is opened to check the battery. If the battery does not catch fire, it is considered to have passed the furnace temperature test.

[0051] Furnace temperature test under the battery pressurized charging regime: Constant current charging is performed at a rate of 0.7C in a 25°C constant temperature chamber. When the voltage reaches the cutoff voltage (typically the system voltage + 30mV), the charging regime switches to constant voltage mode to continue charging until the 0.02C cutoff current is reached. After charging, the battery is heated from room temperature (25°C) to 130°C at a rate of 5°C / min for a constant temperature phase, held at this temperature for 60 minutes. After the time is up, the constant temperature chamber is opened to check the battery. If the battery does not ignite, it is considered to have passed the furnace temperature test.

[0052] 5C capacity retention rate: At 25℃, constant current and constant voltage charging is performed at 0.7C, with a cutoff current of 0.02C. Then, discharge is performed at 0.2C to 3.0V, and the discharge capacity is recorded as C1. Then, full charge is performed again at a higher rate, and then discharge is performed at a 5C rate to 3.0V, and the discharge capacity is recorded as C2. Calculate the 5C capacity retention rate = C2 / C1*100%.

[0053] Δt temperature rise / ℃: First, place the depleted battery in a constant temperature room at 25℃ for 4 hours. When the temperature reaches equilibrium, record the temperature t1 at the battery tab. Then, start constant current and constant voltage charging at a rate of 5C. Record the highest temperature t2 at the battery tab during the full charge process. Δt temperature rise / ℃ = t2 - t1.

[0054] Preparation Example 1:

[0055] Positive electrode structure 1: The foil material is aluminum foil, 9μm thick; the positive electrode active material layer includes: the positive electrode active material is LiCoO2, accounting for 98.0% by mass; the conductive agent is conductive carbon black, accounting for 1.0% by mass; the binder is polyvinylidene fluoride, accounting for 1.0% by mass; wherein, the solvent in the slurry forming the positive electrode active material layer is NMP; according to Figure 3 The structure of the electrode shown is achieved by extrusion transfer coating to form the positive electrode, wherein an active material layer is formed by coating in the fifth region and multiple tabs are formed by stamping in the fourth region to form a full tab structure.

[0056] Positive electrode structure 2: The foil material is aluminum foil, 9μm thick; the positive electrode active material layer includes: the positive electrode active material is LiCoO2, accounting for 98.0% by mass; the conductive agent is conductive carbon black, accounting for 1.0% by mass; the binder is polyvinylidene fluoride, accounting for 1.0% by mass; the heat insulation coating includes: the crystalline material TlSb3Co, accounting for 96.6% by mass; the dispersant is sodium carboxymethyl cellulose, accounting for 1.7% by mass; the binder is SBR, accounting for 1.7% by mass; wherein, the solvent in the slurry forming the positive electrode active material layer is NMP, and the solvent in the slurry forming the heat insulation coating is NMP; according to Figure 2 The structure of the electrode shown is that the positive electrode is coated by extrusion transfer coating, wherein an active material layer is coated in the third region, a heat insulation coating is coated in the second region, and multiple tabs are stamped in the first region to form a full tab structure.

[0057] Negative electrode structure 1: The foil material is high-strength copper foil, 5μm thick; the negative electrode active material layer includes: the negative electrode active material is mesophase carbon microspheres, accounting for 96.50% by mass; the conductive agent is carbon nanotubes, accounting for 0.90% by mass; the binder is SBR, accounting for 1.30% by mass; and the dispersant is sodium carboxymethyl cellulose, accounting for 1.30% by mass. The solvent in the slurry forming the negative electrode active material layer is deionized water, according to... Figure 3 The structure of the electrode shown is that the negative electrode is coated by extrusion transfer coating, wherein an active material layer is coated in the fifth region and multiple tabs are stamped in the fourth region to form a full tab structure.

[0058] Negative electrode structure 2: The foil material is high-strength copper foil, 5μm thick; the negative electrode active material layer includes: the negative electrode active material is mesophase carbon microspheres, accounting for 96.50% by mass; the conductive agent is carbon nanotubes, accounting for 0.90% by mass; the binder is SBR, accounting for 1.30% by mass; and the dispersant is sodium carboxymethyl cellulose, accounting for 1.30% by mass; the heat insulation coating includes: crystalline material TlSb3Co, accounting for 96.6% by mass; the dispersant is sodium carboxymethyl cellulose, accounting for 1.7% by mass; and the binder is SBR, accounting for 1.7% by mass; wherein, the solvent in the slurry forming the negative electrode active material layer is deionized water, and the solvent in the slurry forming the heat insulation coating is deionized water; according to Figure 2 The structure of the electrode shown is that the negative electrode is coated by extrusion transfer coating, wherein an active material layer is coated in the third region, a heat insulation coating is coated in the second region, and multiple tabs are stamped in the first region to form a full tab structure.

[0059] Electrolyte: EC:EMC:DEC = 3:5:2, LiPF6 mass percentage 13%;

[0060] Separator: The separator coating structure is 1+7+2+1, where 1 indicates that there is a 1μm thick adhesive layer on both sides (the adhesive is PVDF adhesive), 2μm indicates that there is a 2μm ceramic coating (Al2O3 coating) on ​​one side, and 7μm indicates that the base membrane is a 7μm PE base membrane.

[0061] Example 1:

[0062] Using the above-mentioned positive electrode structure 2 and negative electrode structure 2, coating and control are carried out according to the above formula to obtain positive and negative electrode sheets with a heat insulation coating of 0.2 mm width on one side (the width of the second region is 0.2 mm). These are then used in combination with the above-mentioned separator to obtain a core. The core is then packaged, injected with electrolyte, formed, resealed, sorted, subjected to OCV, and short-term cycle to obtain a battery for furnace temperature testing.

[0063] Example 2:

[0064] Using the above-mentioned positive electrode structure 2 and negative electrode structure 2, coating and control are carried out according to the above formula to obtain positive and negative electrode sheets with a heat insulation coating of 0.5 mm width on one side (the width of the second region is 0.5 mm). These are then used in combination with the above-mentioned separator to obtain a core. The core is then packaged, injected with electrolyte, formed, resealed, sorted, subjected to OCV, and short-term cycle to obtain a battery for furnace temperature testing.

[0065] Example 3:

[0066] Using the above positive electrode structure 2 and negative electrode structure 2, coating and control are carried out according to the above formula to obtain positive and negative electrode sheets with a heat insulation coating of 2mm width on one side (the width of the second region is 2mm). They are then used in combination with the above separator to obtain a core, which is then packaged, injected with electrolyte, formed, resealed, sorted, OCV, and short-term cycled to obtain a battery for furnace temperature testing.

[0067] Example 4:

[0068] Using the above positive electrode structure 2 and negative electrode structure 2, coating and control are carried out according to the above formula to obtain positive and negative electrode sheets with a heat insulation coating of 3mm width on one side (the width of the second region is 3mm). These are then used in combination with the above separator to obtain a core, which is then packaged, injected with electrolyte, formed, resealed, sorted, OCV, and short-term cycled to obtain a battery for furnace temperature testing.

[0069] Example 5:

[0070] Using the above-mentioned positive electrode structure 2 and negative electrode structure 2, coating and control are carried out according to the above formula to obtain positive and negative electrode sheets with a heat insulation coating of 5mm width on one side (the width of the second region is 5mm). These are then used in conjunction with the above-mentioned separator to obtain a core, which is then packaged, injected with electrolyte, formed, resealed, sorted, subjected to OCV, and short-term cycle to obtain a battery for furnace temperature testing.

[0071] Example 6:

[0072] Using the above-mentioned positive electrode structure 1 and negative electrode structure 2, and coating control according to the above formula, a negative electrode with a heat-insulating coating with a single-sided width of 0.2 mm (the width of the second region is 0.2 mm) is obtained for later use, and a positive electrode without a heat-insulating coating is obtained for later use. It is used in combination with the above-mentioned separator to obtain a core, which is then packaged, injected with electrolyte, formed, resealed, sorted, OCV, and short-term cycled to obtain a battery for furnace temperature testing.

[0073] Example 7:

[0074] Using the above-mentioned positive electrode structure 1 and negative electrode structure 2, and coating control according to the above formula, a negative electrode with a heat-insulating coating with a single-sided width of 0.5 mm (the second region width is 0.5 mm) is prepared for use, and a positive electrode without a heat-insulating coating is prepared for use. It is used in combination with the above-mentioned separator to obtain a core, which is then packaged, injected with electrolyte, formed, resealed, sorted, OCV, and short-term cycled to obtain a battery for furnace temperature testing.

[0075] Example 8:

[0076] Using the above-mentioned positive electrode structure 1 and negative electrode structure 2, and coating control according to the above formula, a negative electrode with a heat-insulating coating with a single-sided width of 2mm (the width of the second region is 2mm) is obtained for later use, and a positive electrode without a heat-insulating coating is obtained for later use. It is used in combination with the above-mentioned separator to obtain a core, which is then packaged, injected with liquid, formed, resealed, sorted, OCV, and short-term cycled to obtain a battery for furnace temperature testing.

[0077] Example 9:

[0078] Using the above-mentioned positive electrode structure 1 and negative electrode structure 2, and coating control according to the above formula, a negative electrode with a heat-insulating coating with a single-sided width of 3mm (the width of the second region is 3mm) is obtained for later use, and a positive electrode without a heat-insulating coating is obtained for later use. It is used in combination with the above-mentioned separator to obtain a core, which is then packaged, injected with liquid, formed, resealed, sorted, OCV, and short-term cycled to obtain a battery for furnace temperature testing.

[0079] Example 10:

[0080] Using the above-mentioned positive electrode structure 1 and negative electrode structure 2, and coating control according to the above formula, a negative electrode with a heat-insulating coating with a single-sided width of 5mm (the width of the second region is 5mm) is obtained for later use, and a positive electrode without a heat-insulating coating is obtained for later use. It is used in combination with the above-mentioned separator to obtain a core, which is then packaged, injected with liquid, formed, resealed, sorted, OCV, and short-term cycled to obtain a battery for furnace temperature testing.

[0081] Example 11:

[0082] Using the above-mentioned positive electrode structure 2 and negative electrode structure 1, coating and control are carried out according to the above formula to obtain a positive electrode with a heat insulation coating with a single-sided width of 0.2mm (the width of the second region is 0.2mm) for later use, and a negative electrode without heat insulation coating for later use. They are used in combination with the above-mentioned separator to obtain a core, which is then packaged, injected with electrolyte, formed, resealed, sorted, OCV, and short-term cycled to obtain a battery for furnace temperature testing.

[0083] Example 12:

[0084] Using the above-mentioned positive electrode structure 2 and negative electrode structure 1, coating and control are carried out according to the above formula to obtain a positive electrode with a heat insulation coating with a single-sided width of 0.5mm (the width of the second region is 0.5mm) for later use, and a negative electrode without heat insulation coating for later use. They are used in combination with the above-mentioned separator to obtain a core, which is then packaged, injected with liquid, formed, resealed, sorted, OCV, and short-term cycled to obtain a battery for furnace temperature testing.

[0085] Example 13:

[0086] Using the above-mentioned positive electrode structure 2 and negative electrode structure 1, coating and control are carried out according to the above formula to obtain a positive electrode with a heat insulation coating with a width of 2mm on one side (the width of the second region is 2mm) for later use, and a negative electrode without heat insulation coating for later use. They are used in combination with the above-mentioned separator to obtain a core, which is then packaged, injected with liquid, formed, resealed, sorted, OCV, and short-term cycled to obtain a battery for furnace temperature testing.

[0087] Example 14:

[0088] Using the above-mentioned positive electrode structure 2 and negative electrode structure 1, coating and control are carried out according to the above formula to obtain a positive electrode with a heat insulation coating with a width of 3mm on one side (the width of the second region is 3mm) for later use, and a negative electrode without heat insulation coating for later use. They are used together with the above-mentioned separator to obtain a core, which is then packaged, injected with liquid, formed, resealed, sorted, OCV, and short-term cycled to obtain a battery for furnace temperature testing.

[0089] Example 15:

[0090] Using the above-mentioned positive electrode structure 2 and negative electrode structure 1, coating and control are carried out according to the above formula to obtain a positive electrode with a heat insulation coating with a single-sided width of 5mm (the width of the second region is 5mm) for later use, and a negative electrode without heat insulation coating for later use. They are used in combination with the above-mentioned separator to obtain a core, which is then packaged, injected with liquid, formed, resealed, sorted, OCV, and short-term cycled to obtain a battery for furnace temperature testing.

[0091] Comparative Example 1:

[0092] Using the above positive electrode structure 1 and negative electrode structure 1, coating and control are carried out according to the above formula to obtain positive and negative electrode sheets without heat insulation coating for later use. They are used in combination with the above separator to obtain core, and then packaged, injected, formed, resealed, sorted, OCV, and short-term cycled to obtain battery for furnace temperature testing.

[0093] Following the performance testing process described above, the obtained battery underwent performance testing, and the following results were obtained:

[0094]

[0095] As shown in the table above, with the increase in the width of the heat insulation coating, the pass rate of the cell furnace temperature test is significantly improved, and the battery temperature rise effect is significantly reduced. Overall, the effect of coating both positive and negative electrodes is greater than coating only the negative electrode, which in turn is greater than coating only the positive electrode. However, as the effective area of ​​the electrode sheets is compressed, the actual energy utilization of the cell decreases, resulting in a significant drop in energy density. Considering both safety and energy density, a heat insulation coating width of 0.5 mm can be significantly increased, and reaching 2 mm essentially ensures that all cells pass the furnace temperature test.

[0096] The embodiments of the present invention have been described above. However, the present invention is not limited to the above embodiments. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A lithium-ion battery, the lithium-ion battery comprising electrodes, characterized in that, The electrode includes a current collector, an active material layer, and a heat-insulating coating; the current collector includes a first region, a second region, and a third region arranged sequentially along the width direction of the current collector; wherein the heat-insulating coating is disposed on the second region, and the active material layer is disposed on the third region; the width of the second region is 0.5mm~5mm; The heat-insulating coating comprises a crystalline material, a binder, and a conductive agent, wherein the chemical formula of the crystalline material is TlSb3Co.

2. The lithium-ion battery according to claim 1, characterized in that, The electrode is either a positive electrode or a negative electrode.

3. The lithium-ion battery according to claim 1, characterized in that, The heat insulation coating comprises the following components by mass percentage: 94wt%~99.8wt% crystalline material, 0.1wt%~3wt% binder, and 0.1wt%~3wt% conductive agent.

4. The lithium-ion battery according to claim 1, characterized in that, The crystalline material TlSb3Co has a framework structure made up of "cages" composed of cobalt and antimony atoms, with each "cage" filled with a single thallium atom.

5. The lithium-ion battery according to claim 1, characterized in that, A full-tip structure or a half-tip structure is provided on the first region.

6. The lithium-ion battery according to claim 1, characterized in that, The width of the first region is 10mm to 30mm; the width of the third region is 50mm to 100mm.

7. The lithium-ion battery according to claim 1, characterized in that, The active material layer includes active material, binder, and conductive agent.

8. The lithium-ion battery according to claim 7, characterized in that, The active material layer comprises the following components by mass percentage: 80-99.8 wt% active material, 0.1-10 wt% conductive agent, and 0.1-10 wt% binder.

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