Battery separator, battery, and electric device

Abstract

This utility model discloses a battery separator, a battery, and an electrical device, relating to the field of batteries. At least one side of the battery separator is a tab-corresponding side. The battery separator includes a first region and a second region, wherein the distance between the first region and the tab-corresponding side is greater than the distance between the second region and the tab-corresponding side. The ion impedance of the first region is less than the ion impedance of the second region. The battery separator according to embodiments of this utility model helps to achieve more uniform lithium-ion distribution and heat management, improving battery performance, safety, and lifespan.

Description

Technical Field

[0001] This utility model relates to the field of batteries, specifically to a battery separator, a battery, and an electrical device. Background Technology

[0002] In existing technologies, some lithium-ion batteries use separators with uniform in-plane pore structures, which leads to a significant increase in current density and Joule heat near the tabs, an increase in the lithium-ion diffusion coefficient, and uneven distribution of lithium ions on the electrodes. This further amplifies the current density and heat gradient, affecting battery safety and lifespan.

[0003] Therefore, there is room for improvement in battery separators. Utility Model Content

[0004] The present invention aims to at least solve one of the technical problems existing in the prior art. Therefore, the first aspect of the present invention aims to provide a battery separator that facilitates more uniform lithium-ion distribution and heat management, thereby improving battery performance, safety, and lifespan.

[0005] The second aspect of this utility model aims to provide a battery having the aforementioned battery separator.

[0006] The objective of the third aspect of this utility model is to provide an electrical device having the aforementioned battery.

[0007] According to a first aspect embodiment of the present invention, the battery separator has at least one side that is a tab-corresponding side. The battery separator includes a first region and a second region, wherein the distance between the first region and the tab-corresponding side is greater than the distance between the second region and the tab-corresponding side. The ion impedance of the first region is less than the ion impedance of the second region.

[0008] According to an embodiment of the present invention, the battery separator is divided into a first region and a second region. The first region is farther from the tabs and has lower ionic impedance, allowing lithium ions to pass through the separator more quickly and improving the transport efficiency in this region. The second region, closer to the tabs, has higher ionic impedance, limiting the rapid migration of lithium ions and preventing excessively high local lithium ion concentrations that could lead to heat accumulation. This partitioned design effectively optimizes the distribution of lithium ions across the entire battery separator, reduces local overheating caused by uneven current density, and improves battery safety and cycle life.

[0009] According to some optional embodiments of the present invention, the battery separator is provided with ion vias for ions of the electrolyte to pass through; the sum of the areas of all the ion vias per unit area in the first region is greater than the sum of the areas of all the ion vias per unit area in the second region.

[0010] In some alternative embodiments, the aperture of a single ion via on the first region is larger than the aperture of a single ion via on the second region.

[0011] According to some optional embodiments, the ion pores on the battery separator are uniformly spaced.

[0012] According to some optional embodiments of the present invention, the thickness of the first region of the battery separator is less than the thickness of the second region.

[0013] According to some optional embodiments of the present invention, the battery separator includes a substrate layer and a sol-gel coating disposed along the thickness direction of the battery separator. The substrate layer is provided with ion-passing pores for ions of the electrolyte to pass through. The concentration of nanoparticles in the sol-gel coating in the first region is less than the concentration of nanoparticles in the sol-gel coating in the second region.

[0014] Furthermore, the battery separator is elongated, and the two opposite short sides of the battery separator are the sides corresponding to the tabs.

[0015] Further optionally, the battery separator is divided into at least two regions from the midline of the battery separator to the corresponding edge of the tab, and the ion resistance of the at least two regions increases sequentially; wherein the distance from the midline to the corresponding edge of the tab on both sides is equal.

[0016] A battery according to a second aspect of the present invention includes: a casing, electrodes, and a separator. The electrodes include a positive electrode and a negative electrode, and both the positive electrode and the negative electrode are provided with tabs. The separator is disposed inside the casing and sandwiched between the positive electrode and the negative electrode. The separator is the battery separator of the first aspect of the present invention.

[0017] The electrical device according to a third aspect of the present invention includes a battery according to a second aspect of the present invention.

[0018] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0019] The above and / or additional aspects and advantages of this utility model will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0020] Figure 1 This is a schematic diagram of the current and Joule heat distribution of a battery assembled with a separator with uniform pore size in some existing technologies.

[0021] Figure 2 This is a schematic diagram of the structure of a battery assembled with a separator that has uniform pore size, as is common in some existing technologies.

[0022] Figure 3 This is a schematic diagram of the battery separator structure in some embodiments of the present invention;

[0023] Figure 4 This refers to the battery separator in some embodiments of the present invention;

[0024] Figure 5 This is a schematic diagram showing the arrangement of ion vias on the battery separator in some embodiments of this utility model;

[0025] Figure 6 This is a schematic diagram of the coating of nanoparticles on the battery separator in some embodiments of this utility model;

[0026] Figure 7 This is a side view of the battery separator in some embodiments of the present invention.

[0027] Figure label:

[0028] In the existing technology

[0029] 1000' battery, 100' separator

[0030] In this application

[0031] Battery separator 100, long side 11, short side 12, tab corresponding side 20, first area 31, second area 32, ion pore 40, nanoparticles 50, median line ML. Detailed Implementation

[0032] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.

[0033] In the description of this utility model, it should be understood that the terms "length," "thickness," etc., indicating orientation or positional relationships are based on the orientation or positional relationships shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, features defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0034] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0035] It should be noted that, in the description of this application, "and / or" means that there are three parallel options. Taking "A and / or B" as an example, it includes option A, option B, or an option that satisfies both A and B.

[0036] As mentioned in the background section, some existing lithium-ion batteries 1000' employ separators 100' with uniform in-plane pore structure. Especially under large-size (>1 meter) and high-rate operating conditions, the problems of uneven heat and SOC distribution inside the battery 1000' are exacerbated, seriously threatening safety and cycle life. Please refer to [the following text] for further details. Figure 1 For a 1000' battery, the closer the current is to the tab, the higher the current density of the current collector and the more pronounced the Joule heating. (See also...) Figure 2 The closer to the electrode, the more pronounced the lithium-ion dynamics, meaning a larger lithium-ion diffusion coefficient, which further leads to uneven lithium-ion distribution on the electrode.

[0037] To improve the above problems, please refer to the following: Figures 3-7 A battery separator 100 according to a first aspect embodiment of the present invention is described.

[0038] It is worth noting that the battery separator 100 is a layer of material located between the positive and negative electrodes. Its main function is to prevent the positive and negative electrodes from directly contacting each other and causing a short circuit, while allowing ions to pass freely during charging and discharging, thus maintaining the electrochemical reaction inside the battery.

[0039] In this embodiment, at least one side of the battery separator 100 is a tab-corresponding side 20. In some technical solutions, one side of the battery separator 100 is the tab-corresponding side 20. In still other technical solutions, combined with... Figure 3 The battery separator 100 has tabs on both sides corresponding to the sides 20.

[0040] Please combine Figures 3-7 The battery separator 100 includes a first region 31 and a second region 32. The distance between the first region 31 and the corresponding side 20 of a tab is greater than the distance between the second region 32 and the corresponding side 20 of the tab.

[0041] With this configuration, the distance between the first region 31 and the corresponding edge 20 of the electrode is relatively large, while the distance between the second region 32 and the corresponding edge 20 of the electrode is relatively small. Compared with the first region 31, the second region 32 has a larger lithium-ion diffusion coefficient.

[0042] Therefore, in order to balance the lithium-ion distribution in different regions of the battery separator 100, the ion impedance of the first region 31 in the battery separator 100 proposed in this application is lower than that of the second region 32. That is, the first region 31 is farther away from the corresponding edge 20 of the tab, and its ion impedance is smaller, which promotes a more uniform distribution of lithium ions; the second region 32 is closer to the corresponding edge 20 of the tab, and its ion impedance is larger, which prevents excessively high local lithium-ion concentration and avoids heat concentration.

[0043] Specifically, the first region 31 has a lower ion impedance: this means that by designing a lower ion impedance, lithium ions can pass through the region more easily, increasing the lithium ion concentration and compensating for the slowed diffusion rate caused by moving away from the electrode.

[0044] The second region 32 has a higher ion impedance: by setting a higher ion impedance, the rapid migration of lithium ions in this region is limited, the lithium ion concentration is reduced, and the excessively fast ion flow caused by the high diffusion coefficient is balanced.

[0045] Therefore, this partitioning configuration optimizes the distribution of lithium ions across the entire separator by adjusting the ion impedance of different regions, ensuring that the number of lithium ion insertions / extractions in different areas of the electrode separator remains as consistent as possible. According to Fick's first law (see Equation 1), the current density... Equal to the lithium-ion diffusion coefficient and lithium ion concentration gradient The product of the current density and the number of lithium ions per unit time. From Formula 2, it can be seen that the current density per unit time is related to the number of lithium ions. The current density is proportional to the product of the lithium-ion diffusion coefficient and the concentration (Formula 3). Since the lithium-ion diffusion coefficient of the second region 32 is greater than that of the first region 31, by reducing the lithium-ion concentration of the second region 32 and / or increasing the lithium-ion concentration of the first region 31, the number of lithium-ion insertions per unit time at various locations of the electrode dressing can be made as consistent as possible.

[0046]

[0047] Unit time,

[0048] Therefore Right now (Formula 3).

[0049] This design not only improves the overall performance, safety, and lifespan of the battery, but also effectively alleviates localized overheating caused by uneven current density, ensuring the consistency of the SOC (state of charge) value throughout the battery. Consistent SOC maximizes the utilization of the active material's capacity while preventing localized overcharging or over-discharging during charging and discharging, thus extending the lifespan of the active materials. Furthermore, this design helps prevent the continued widening of differences in battery heat distribution, maintaining a stable battery temperature.

[0050] In some optional embodiments, the battery separator 100 is provided with ion vias 40 for ions of the electrolyte to pass through. By adjusting the porosity and / or the pore depth of these ion vias 40 on the first region 31 and / or the second region 32, the ion impedance of the first region 31 can be made smaller than that of the second region 32.

[0051] Specifically, in some embodiments, the porosity of the ion-through holes 40 on the first region 31 is greater than that on the second region 32. Porosity refers to the proportion of the area of ​​open ion-through holes 40 on the separator surface to the total area. A higher porosity means more open pores on the separator surface, allowing more electrolyte to fill them, thus providing a larger migration channel for lithium ions. This configuration, by increasing the porosity of the ion-through holes 40 in the first region 31, makes lithium ion migration in this region smoother, reducing the ion resistance of the first region 31. The lower porosity of the second region 32 limits the excessively rapid migration of lithium ions, reduces the current density and heat accumulation near the corresponding edge 20 of the electrode tab, avoids local overheating, and thus improves the safety and lifespan of the battery.

[0052] Alternatively, the depth of the ion vias 40 in the first region 31 is less than the depth of the ion vias 40 in the second region 32. It is understood that the via depth refers to the depth of the ion vias 40 on the membrane extending from one surface to the other. Deeper ion vias 40 increase the length of the ion migration path, thereby increasing the resistance to ion migration; while shallower vias shorten the migration path, reducing the resistance to ion migration. With this configuration, the shallower via depth in the first region 31 reduces ion migration resistance; the increased via depth in the second region 32 increases migration resistance, thus balancing lithium-ion flow.

[0053] like Figure 3 and Figure 4 As shown, according to some optional battery separators 100 of this invention, the battery separator 100 is provided with ion-passing holes 40 for ions of the electrolyte to pass through. The sum of the areas of all ion-passing holes 40 per unit area in the first region 31 is greater than the sum of the areas of all ion-passing holes 40 per unit area in the second region 32.

[0054] In the above technical solution, the first region 31 has a larger open area of ​​ion pores, providing a larger effective channel, allowing more lithium ions to pass through the separator quickly and reducing ion resistance. This not only compensates for the low current density of the first region 31, but also promotes the uniform distribution of lithium ions.

[0055] In contrast, resistance to ion migration is increased by reducing the sum of the total areas of all ion vias 40 within the second region of 32 units. The smaller open aperture area makes the migration path of lithium ions more restricted in this region, thereby limiting the excessively rapid flow of lithium ions.

[0056] This design effectively balances the flow of lithium ions between different areas, avoids localized overheating, and improves battery safety and cycle life.

[0057] Please see Figure 3 and Figure 4 In some optional embodiments, the aperture of a single ion via 40 on the first region 31 is larger than the aperture of a single ion via 40 on the second region 32.

[0058] By increasing the aperture of the ion via 40 in the first region 31, a larger lithium-ion channel is provided, reducing the resistance of lithium ions crossing the membrane and thus lowering the ion impedance of the first region 31. Since the first region 31 is far from the tab, has a lower current density and a smaller lithium-ion diffusion coefficient, the larger aperture helps to improve lithium-ion transport efficiency and promote a more uniform distribution of lithium ions.

[0059] In contrast, the second region 32 is closer to the tab, has a higher current density and a larger lithium-ion diffusion coefficient. The smaller pore size increases the resistance to lithium-ion migration, limiting the rapid flow of lithium ions in this region and avoiding heat accumulation and performance degradation caused by excessively high local lithium-ion concentration. This zoned design effectively balances the lithium-ion flow in different regions, prevents local overheating, and improves the overall performance and safety of the battery.

[0060] Therefore, by adjusting the pore size, the distribution of lithium ions inside the battery is optimized, ensuring a more uniform and stable electrochemical reaction in each region. Here, the ion via 40 can be circular or other shapes. When the ion via 40 is circular, the pore size is defined as the diameter of the circle; while for other shapes of ion via 40, the pore size is defined as the diameter of the equivalent circle.

[0061] Optionally, see Figure 5 By changing the distribution density of the ion vias 40, more precise control of ion migration can be achieved in different regions.

[0062] Further optional, such as Figure 4As shown, ion pores 40 are evenly spaced on the battery separator 100.

[0063] By setting uniformly spaced ion vias 40, the migration path of lithium ions on the separator within the same area is ensured to be consistent, avoiding differences in ion transport rates in local areas due to uneven via distribution. Uniformly distributed vias help achieve a more balanced current density and heat distribution, improving battery safety and cycle life, while further optimizing the overall battery performance.

[0064] Optionally, the distribution density of ion vias 40 on the first region 31 is different from that on the second region 32. This allows for more precise control of ion migration.

[0065] In some alternative embodiments, such as Figure 7 As shown, the thickness of the first region 31 is less than the thickness of the second region 32. This results in a shorter path for the ion vias 40 through the first region 31, thereby reducing ion migration resistance and improving lithium-ion transport efficiency. In contrast, the thicker design of the second region 32 increases the path length of the ion vias 40, increasing ion migration resistance, effectively limiting the rapid flow of lithium ions, preventing local overheating and uneven concentration, and improving battery safety and performance.

[0066] According to some optional embodiments of the present invention, the battery separator 100 includes a substrate layer and a sol-gel coating disposed along the thickness direction of the battery separator 100, wherein the substrate layer is provided with ion vias 40 for ions of the electrolyte to pass through. Figure 6 As shown, the concentration of nanoparticles 50 in the sol-coated layer of the first region 31 is less than the concentration of nanoparticles 50 in the sol-coated layer of the second region 32.

[0067] In the first region 31, this invention employs a low-concentration sol-gel coating of nanoparticles 50. This means that the ion vias 40 on the first region 31 are covered with sparser nanoparticles 50, making the ion vias 40 on the substrate layer more open and thus providing a larger effective channel area. Lithium ions can pass through these vias more quickly, reducing the time and energy required to cross the membrane, lowering ion resistance, and promoting the efficient transport of lithium ions in the first region 31.

[0068] Specifically, since the first region 31 is far from the tab, has a lower current density and a smaller lithium-ion diffusion coefficient, a thinner sol-gel coating is used. This not only gives the first region 31 a larger open pore size, reducing the resistance of lithium ions to penetrating the separator and increasing the concentration of lithium ions that permeate, but also compensates for the slowed diffusion rate caused by its distance from the tab.

[0069] In contrast, the second region 32, located near the tab edge 20, exhibits a higher current density and a larger lithium-ion diffusion coefficient. To prevent localized heat accumulation in this region due to excessively high lithium-ion concentration, this invention employs a sol-gel coating with a high concentration of nanoparticles 50. The higher concentration of nanoparticles 50 increases the filling density on the separator surface, thereby limiting the openness of the ion pores 40 and increasing the resistance to ion migration. Therefore, the thicker sol-gel coating and smaller open pore size of the second region 32 increase the resistance to lithium-ion penetration through the separator, resulting in a lower concentration of penetrating lithium-ions. This configuration effectively balances lithium-ion flow between different regions, avoids localized overheating, and improves battery safety and cycle life.

[0070] According to some alternative embodiments, the battery separator 100 is elongated, and the two opposite short sides 12 of the battery separator 100 are both tab-corresponding sides 20.

[0071] In this embodiment, the battery separator 100 has a higher current density and a larger lithium-ion diffusion coefficient near both ends. By setting a higher ion impedance in these regions, the excessively rapid flow of lithium ions can be effectively limited, preventing local overheating and uneven lithium-ion concentration, thereby improving battery safety and cycle life.

[0072] Optionally, the battery separator 100 is divided into at least two regions from the midline ML to the corresponding edge 20 of the tab, and the ion resistance of the at least two regions increases sequentially. The distance from the midline ML to the corresponding edge 20 of the tabs on both sides is equal.

[0073] Specifically, the distances from the median line ML to the corresponding edges 20 of the two tabs are equal, resulting in better symmetry and balance in the partitioning. Within these partitions, the ion resistance increases progressively from the end closer to the median line ML to the end closer to the tab. This gradual change in ion resistance helps optimize the lithium-ion transport path, making the lithium-ion flow more uniform, thereby improving the consistency of heat distribution in the battery separator 100 and reducing or even avoiding localized overheating. By maintaining the battery's temperature, not only is battery safety improved, but its lifespan is also extended.

[0074] Furthermore, by adjusting the overall characteristics of different regions to achieve gradual changes in ion impedance, the production process is simplified, manufacturing costs are reduced, and economic efficiency is improved.

[0075] Combination Figure 4 and Figure 7The battery separator 100 includes a first region 31 and two second regions 32. The two second regions 32 are respectively placed on both sides of the first region 31, and the distance from the center line ML to both sides is kept equal to ensure the symmetry of the separator design. This symmetrical structure simplifies the manufacturing process, reduces production difficulty, and at the same time reduces local overheating and maintains the stability of the battery during use.

[0076] In some optional embodiments, the battery separator 100 includes a long side 11 located between two short sides 12. The length of the long side 11 is L. The length of the first region 31 is L1, satisfying 0.3L≤L1≤0.7L, wherein the pore size of the ion via 40 in the first region 31 is D1, satisfying 200nm≤D1≤1000nm. The length of the second region 32 is L2, satisfying L2≤0.3L, wherein the pore size of the ion via 40 in the second region 32 is D2, 10nm≤D1≤200nm. By controlling the different pore sizes of the ion via 40 in the first region 31 and the second region 32, the lithium-ion transport path can be effectively controlled, improving the uniformity of lithium-ion distribution inside the battery, reducing the risk of local overheating, and improving the safety and cycle life of the battery.

[0077] A battery according to a second aspect embodiment of the present invention includes: a casing, electrodes, and a separator. The electrodes include a positive electrode and a negative electrode, each having tabs. The separator is disposed within the casing and sandwiched between the positive and negative electrodes; the separator is the battery separator 100 of the first aspect embodiment of the present invention.

[0078] The battery of this utility model embodiment optimizes lithium-ion distribution, reduces local overheating, and improves battery safety, performance, and cycle life by integrating the separator of the first aspect embodiment of this application.

[0079] The electrical device according to a third aspect embodiment of the present invention includes a battery according to a second aspect embodiment of the present invention. It is worth noting that the electrical device can be a portable electronic device, such as a smartphone or tablet computer, or an energy storage system, such as a household or industrial battery energy storage system, or a new energy vehicle or range-extended vehicle. Using the battery according to the third aspect embodiment of the present invention helps to improve the safety of the electrical device.

[0080] The following is for reference. Figure 3 - Figure 7 The battery separator 100 according to an embodiment of the present invention is described in detail with reference to a specific example. It is to be understood that the following description is merely illustrative and not intended to limit the scope of the invention.

[0081] Example 1

[0082] See Figures 3-5The battery separator 100 is elongated, and the two opposite short sides 12 of the battery separator 100 are the corresponding sides 20 of the tabs.

[0083] From the midline ML of the battery separator 100 to the corresponding edge 20 of the tab, the battery separator 100 is divided into at least two regions, and the ion resistance of the at least two regions increases sequentially. The distance from the midline ML to the corresponding edge 20 of the tabs on both sides is equal.

[0084] The battery separator 100 includes: a first region 31 and a second region 32, wherein the distance between the first region 31 and the corresponding side 20 of a tab is greater than the distance between the second region 32 and the corresponding side 20 of the tab;

[0085] The ion impedance of the first region 31 is less than that of the second region 32.

[0086] The battery separator 100 is provided with ion pores 40 for ions of the electrolyte to pass through.

[0087] The sum of the areas of all ion vias 40 per unit area in the first region 31 is greater than the sum of the areas of all ion vias 40 per unit area in the second region 32.

[0088] The aperture of a single ion via 40 in the first region 31 is larger than the aperture of a single ion via 40 in the second region 32.

[0089] The battery separator 100 has ion pores 40 evenly spaced.

[0090] Example 2

[0091] See Figure 7 The structure of the battery separator 100 in this second embodiment is basically the same as that in the first embodiment, except that the thickness of the first region 31 in the battery separator 100 is less than the thickness of the second region 32.

[0092] Example 3

[0093] See Figure 6 The structure of the battery separator 100 in this embodiment is basically the same as that in embodiment one. The difference is that the battery separator 100 includes a substrate layer and a sol coating layer arranged along the thickness direction of the battery separator 100. The substrate layer is provided with ion vias 40 for ions of the electrolyte to pass through.

[0094] The concentration of nanoparticles 50 in the sol-coated layer of the first region 31 is lower than the concentration of nanoparticles 50 in the sol-coated layer of the second region 32.

[0095] Other components of the battery separator 100 according to embodiments of the present invention, such as the battery and the power supply device, as well as the operation, are known to those skilled in the art and will not be described in detail here.

[0096] In this specification, the terms "embodiment," "example," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0097] Although embodiments of the present invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A battery separator, characterized in that, At least one side of the battery separator is the side corresponding to the tab provided with the tab; The battery separator includes a first region and a second region, wherein the distance between the first region and the corresponding side of the tab is greater than the distance between the second region and the corresponding side of the tab; The ion impedance of the first region is less than that of the second region.

2. The battery separator according to claim 1, characterized in that, The battery separator is provided with ion-passing pores for ions of the electrolyte to pass through; The sum of the areas of all the ion vias per unit area in the first region is greater than the sum of the areas of all the ion vias per unit area in the second region.

3. The battery separator according to claim 2, characterized in that, The aperture of a single ion via in the first region is larger than the aperture of a single ion via in the second region.

4. The battery separator according to claim 2, characterized in that, The ion pores on the battery separator are evenly spaced.

5. The battery separator according to claim 1, characterized in that, The thickness of the first region is less than the thickness of the second region.

6. The battery separator according to claim 1, characterized in that, The battery separator includes a substrate layer and a sol coating disposed along the thickness direction of the battery separator, wherein the substrate layer is provided with ion vias for ions of the electrolyte to pass through; The concentration of nanoparticles in the sol-coated layer in the first region is less than the concentration of nanoparticles in the sol-coated layer in the second region.

7. The battery separator according to any one of claims 1-6, characterized in that, The battery separator is elongated, and the two opposite short sides of the battery separator are the sides corresponding to the tabs.

8. The battery separator according to claim 7, characterized in that, From the midline of the battery separator to the corresponding edge of the tab, the battery separator is divided into at least two regions, and the ion resistance of the at least two regions increases sequentially. The distance from the midline to the corresponding sides of the tabs on both sides is equal.

9. A battery, characterized in that, include: case; The electrode includes a positive electrode and a negative electrode, and both the positive electrode and the negative electrode are provided with tabs; A separator is disposed within the housing and sandwiched between the positive electrode and the negative electrode, wherein the separator is a battery separator according to any one of claims 1-8.

10. An electrical appliance, characterized in that, Includes the battery according to claim 9.

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