Pole piece, pole core, battery, battery device and electric equipment

Abstract

The utility model belongs to the technical field of batteries, and discloses a pole piece, the pole piece comprises a pole lug and a pole piece body, the pole lug is connected to one end of the pole piece body along the length direction, the pole piece body is provided with a plurality of areas which are arranged in sequence along the length direction, the areas of the areas are the same, and the pole piece body is connected with the pole lug. Each area is provided with a through hole; along the length direction, the ratio of the total area of the through holes in each area to the total area of the corresponding area is the aperture ratio A, the area closest to the tab is set as a first area, the aperture ratio of the first area is A1, the area adjacent to the first area is set as a second area, and the aperture ratio of the second area is A1. The aperture ratio of the first area is denoted as A, the aperture ratio of the second area is denoted as A2, and the like, the aperture ratio of the nth area is denoted as An, A (n-1) is smaller than or equal to An, and at least one A (n-1) is smaller than An. By providing the pole piece which is perforated in the areas sequentially distributed in the length direction, the temperature distribution of the pole piece in the working process can be more uniform, meanwhile, the weight of the pole piece is reduced, the mass specific capacity of the battery is improved, the fast charging performance of the battery is improved, and the service life of the battery is prolonged.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, and in particular to a pole piece, a pole core, a battery, a battery device and electrical equipment. Background Art

[0002] Lithium batteries are widely used in energy storage devices, mobile power supplies and automotive fields. Lithium batteries are composed of multiple single cells. The energy density of the single cell determines the energy density of the lithium battery. The single cell is formed by winding or stacking the pole pieces. In order to enable the pole piece to effectively absorb and store the electrolyte and shorten the diffusion path of lithium ions, it is often necessary to punch holes in the pole piece during the preparation of the pole piece. The structure of a lithium-ion battery includes several parts such as positive and negative pole pieces, diaphragms, electrolytes and shells. When the battery is charged and discharged, the reaction of active substances, battery polarization, and battery internal resistance will generate heat. When the temperature of the lithium battery is between 70 and 80°C, the heat generated by the battery is mainly reaction heat. When the temperature is lower than this, the Joule heat generated by the internal resistance of the battery accounts for a large proportion. Generally, the operating temperature of lithium batteries is below 70°C, so the heat generated by the battery is mainly composed of heat generated by internal resistance.

[0003] Compared with ordinary electrodes, perforated electrodes can improve the adhesion of active materials, adjust the mass distribution of electrodes, and extend the battery cycle life. However, the position where the battery has the highest heating temperature affects the battery's rate performance and applicable ambient temperature. Ordinary perforated electrodes do not solve the problem of uneven heating of the electrodes, that is, the mass distribution of the electrodes is not reasonable, which is not conducive to improving the battery's fast charging performance and extending the battery cycle life. In view of this, we propose a electrode, a battery cell, a battery, a battery device, and an electrical device. Utility Model Content

[0004] The purpose of the utility model is to provide a pole piece, a pole core, a battery and an electrical device. By providing a pole piece with holes punched in areas distributed sequentially in the length direction, the temperature distribution of the pole piece can be more uniform during operation, the weight of the pole piece can be reduced, the battery mass capacity can be increased, the fast charging performance of the battery can be improved and the battery life can be extended.

[0005] To achieve this purpose, the utility model adopts the following technical solutions:

[0006] The utility model discloses a pole piece, comprising a pole ear and a pole piece body, wherein the pole ear is connected to one end of the pole piece body along the length direction, and along the length direction, the pole piece body is provided with a plurality of regions arranged in sequence, each of the regions has the same area, and each of the regions is provided with a through hole; along the length direction, the ratio of the total area of ​​the through holes in each of the regions to the total area of ​​the corresponding regions is the opening rate, which is recorded as A, the region closest to the pole ear is set as the first region, and the opening rate of the first region is recorded as A1, the region adjacent to the first region is set as the second region, and the opening rate of the second region is recorded as A2, and so on, the opening rate of the nth region is recorded as An, A(n-1)≤An and there is at least one A(n-1)<An.

[0007] Optionally, 10%≤A≤80%.

[0008] Optionally, the pole piece body is provided with 9 regions along the length direction.

[0009] Furthermore, the porosity of each of the regions is: A1=A2=A3=A4=A5=A6=10%, A7=A8=20%, A9=40% and / or the porosity of each of the regions is: A1=A2=A3=A4=10%, A5=A6=A7=A8=20%, A8=30%, A9=50%.

[0010] Optionally, along the length direction, the opening rate of each region increases successively.

[0011] Optionally, the plurality of through holes are arranged regularly or irregularly.

[0012] Optionally, each of the regions is provided with a plurality of through holes, and the plurality of through holes have the same aperture.

[0013] Optionally, the through hole is circular and / or polygonal in shape.

[0014] A pole core comprises the pole piece mentioned above.

[0015] A battery comprises the pole core described above.

[0016] A battery device comprises the battery mentioned above.

[0017] An electrical device comprises the battery or battery device mentioned above.

[0018] The purpose of the utility model is to provide a pole piece, a pole core, a battery and an electrical device. By providing a pole piece with holes punched in areas distributed sequentially in the length direction, the temperature distribution of the pole piece can be more uniform during operation, the weight of the pole piece can be reduced, the battery mass capacity can be increased, the fast charging performance of the battery can be improved and the battery life can be extended. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The following drawings of the embodiments of the present invention are used as a part of the present invention for understanding the present invention. The drawings show the embodiments of the present invention and their descriptions, and are used to explain the principle of the present invention.

[0020] Figure 1 It is a schematic diagram of the overall structure of a pole piece with multiple area holes;

[0021] Figure 2 This is a schematic diagram of the temperature distribution simulation of a general pole piece;

[0022] Figure 3 This is a schematic diagram of the temperature distribution simulation of a common hole-opening electrode;

[0023] Figure 4 This is a schematic diagram of the simulation of the temperature distribution of the electrode with holes opened in different regions along the length direction;

[0024] Figure 5 It is the table of positive electrode sheet opening rate and simulated temperature difference results;

[0025] Figure 6 It is the table of the negative electrode sheet opening rate and the simulated temperature difference results;

[0026] Figure 7 It is a schematic diagram of a positive electrode sheet with holes opened in different regions;

[0027] Figure 8 It is a schematic diagram of the negative electrode plate opening with regional openings.

[0028] In the figure:

[0029] 1. pole piece, 11. pole ear; 12. pole piece body, 2. through hole. DETAILED DESCRIPTION

[0030] In the following description, a large number of specific details are given in order to provide a more thorough understanding of the utility model. However, it is obvious to those skilled in the art that the embodiments of the utility model can be implemented without one or more of these details. In other examples, in order to avoid confusion with the embodiments of the utility model, some technical features known in the art are not described. The utility model is further described in detail below in conjunction with the accompanying drawings and examples. It is understood that the specific embodiments described herein are only used to explain the utility model, rather than to limit the utility model. It should also be noted that, for ease of description, only parts related to the utility model rather than all structures are shown in the accompanying drawings.

[0031] In the description of this embodiment, the term "length direction" is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of description and simplification of operation, and does not indicate or imply that the device or structure referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be understood as a limitation on the present utility model.

[0032] In order to make the temperature distribution of the electrode more uniform during operation, retain the advantages of the perforated electrode without significantly increasing the temperature rise of the battery during charging and discharging, reduce the weight of the electrode, improve the battery mass capacity, enhance the fast charging performance of the battery and extend the battery life, this embodiment provides a electrode, a battery cell, a battery and an electrical device.

[0033] like Figure 1As shown, the pole piece 1 includes a pole ear 11 and a pole piece body 12, and a plurality of regions arranged in sequence are provided along the length direction of the pole piece 1, and the region is completely located at the pole ear 11, and the pole ear is connected to one end of the pole piece body 12 along the length direction, and the length direction is the direction from the pole ear 11 to the pole ear body 12, and each of the regions is provided with a through hole 2, and the through hole 2 is provided in the region, that is, a through hole 2 is punched in the pole ear body 12, and no through hole 2 is provided in the pole ear 11, and the regions have the same area and shape, and the regions are distributed in sequence in the length direction of the pole piece 1, that is, the regions are arranged in sequence in the direction from the pole ear 11 to the pole ear body 12, and the through holes 2 in the regions along the length direction of the pole piece The ratio of the total area of ​​to the total area of ​​the region is the porosity, denoted by A, the region closest to the pole lug 11 is set as the first region, the porosity of the first region is denoted by A1, the region adjacent to the first region is set as the second region, the porosity of the second region is denoted by A2, and so on, the porosity of the nth region is denoted by An, characterized in that A(n-1)≤An and there is at least one A(n-1)<An, that is, starting from the pole lug 11 along the length direction, the farther the region is from the pole lug 11, the higher the porosity, the farther the region is from the pole lug 11, the larger the area of ​​the through hole 2 in the region, and there is at least one region whose porosity An is greater than the porosity A(n-1) of another adjacent region closer to the pole lug 11.

[0034] Optionally, 10%≤A≤80% is set. In the set area of ​​the pole ear body 12, the opening rate is selected between 10% and 80%, that is, the ratio of the area of ​​the hole to the area of ​​the area is between 10% and 80%. The pole piece 1 has a better heat dissipation effect when working, and the temperature distribution of the pole piece is more uniform. Calculation of the opening rate of a certain area: the pole piece body 12 is equally divided into a plurality of areas along the length direction, and the total area of ​​each area is equal, which is recorded as S1. One or more through holes 22 are set in each area, and the total area of ​​one or more through holes 2 is recorded as S2. The opening rate A of each area is the ratio of the total area S1 of the area to the total area S2 of all through holes 2 in the area, that is, A=S2 / S1.

[0035] contrast Figure 2 , Figure 3 as well as Figure 4It can be seen that, by comparing the temperature simulation schematic diagram of a general electrode and the temperature distribution simulation schematic diagram of an ordinary perforated electrode, the general electrode is a electrode without a through hole 2 on the electrode body 12, and the ordinary perforated electrode is an ordinary electrode with no restrictions on the total area of ​​the opening and the position of the opening. The temperature color of the temperature distribution simulation diagram of the ordinary perforated electrode is more uniform than the temperature color of the temperature simulation diagram of the general electrode in the working state, and the temperature color distribution of the temperature distribution simulation diagram of the perforated electrode in the length direction is more uniform than the temperature color distribution of the temperature distribution simulation diagram of the ordinary perforated electrode, that is, the temperature distribution of the ordinary perforated electrode in the working state is more uniform than that of the general electrode, and the temperature distribution of the regional perforated electrode in the length direction is more uniform than that of the ordinary perforated electrode in the working state.

[0036] In this embodiment, 9 regions are provided along the length direction of the electrode sheet 1, that is, the positive electrode sheet and the negative electrode sheet are divided into 9 regions along the length direction, and the area of ​​each region is equal. The regions are distributed in sequence along the length direction, and are respectively recorded as A1, A2, A3, A4, A5, A6, A7, A8, and A9.

[0037] like Figure 5As shown, different opening ratio combinations are selected for the regional positive electrode sheets to measure the temperature difference. The opening ratio of the first group of positive electrode sheets is set as: A1=0%, A2=0%, A3=0%, A4=0%, A5=0%, A6=10%, A7=0%, A8=0%, A9=0%. The experimental measurement results are: the highest temperature is 40.58°C, the lowest temperature is 37.528°C, and the temperature difference is 3.052°C. The opening ratio of the second group of positive electrode sheets is set as: A1=5%, A2=5%, A3=5%, A4=5%, A5=5%, A6=5%, A7=5%, A8=5%, A9=5%. The experimental measurement results are: the highest temperature is 44.258°C, the lowest temperature is 37.365°C, and the temperature difference is 3.052°C. The temperature difference is 6.893℃, the third group of opening rates of the positive electrode sheet is set as: A1=10%, A2=10%, A3=10%, A4=10%, A5=10%, A6=10%, A7=10%, A8=10%, A9=10%, the experimental measurement results are: the highest temperature is 42.249℃, the lowest temperature is 39.363℃, and the temperature difference is 2.886℃. The fourth group of opening rates of the positive electrode sheet is set as: A1=10%, A2=10%, A3=10%, A4=10%, A5=10%, A6=10%, A7=10%, A8=10%, A9=20%, the experimental measurement results are: the highest temperature is 42.32℃, the lowest temperature is 39.727℃, and the temperature difference is 2.593℃, the fifth group of opening rates of the positive electrode sheet is set to: A1=10%, A2=10%, A3=10%, A4=10%, A5=10%, A6=10%, A7=10%, A8=20%, A9=20%, the experimental measurement results are: the highest temperature is 42.408℃, the lowest temperature is 39.995℃, and the temperature difference is 2.413℃. The sixth group of opening rates of the positive electrode sheet is set to: A1=10%, A2=10%, A3=10%, A4=10%, A5=10%, A6=10%, A7=20%, A8=20%, A9=20%, the experimental measurement results are: the highest temperature is 42.522℃, the lowest temperature is 40.19℃, and the temperature difference is 2 .332℃, the seventh group of positive electrode opening ratios are set as: A1 = 10%, A2 = 10%, A3 = 10%, A4 = 10%, A5 = 10%, A6 = 20%, A7 = 20%, A8 = 20%, A9 = 20%, the experimental results are: the highest temperature is 42.799℃, the lowest temperature is 40.798℃, the temperature difference is 2.001℃, the eighth group of positive electrode opening ratios are set as: A1 = 10%, A2 = 10%, A3 = 10%, A4 = 10%, A5 = 10%, A6 = 20%, A7 = 20%, A8 = 20%, A9 = 30%, the experimental results are: the highest temperature is 42.482℃, the lowest temperature is 40.605℃, the temperature difference is 1.877℃, the ninth group of positive electrode opening rates are set as: A1=10%, A2=10%, A3=10%, A4=10%, A5=10%, A6=10%, A7=20%, A8=20%, A9=30%, the experimental measurement results are: the highest temperature is 42.985℃, the lowest temperature is 41.428℃, the temperature difference is 1.53℃, the tenth group of positive electrode opening rates are set as: A1=10%, A2=10 %, A3=10%, A4=10%, A5=10%, A6=10%, A7=20%, A8=20%, A9=40%. The experimental results are as follows: the highest temperature is 42.579℃, the lowest temperature is 41.16℃, the temperature difference is 1.419℃, and the opening rate of the eleventh group of positive electrode sheets is set as: A1=10%, A2=10%, A3=10%, A4=10%, A5=20%, A6=20%, A7=20%, A8=20%, A9=40%. 7=20%、A8=30%、A9=50%、The experimental results are as follows: The highest temperature is 42.221℃、The lowest temperature is 40.08℃、The temperature difference is 2.141℃、The opening rate of the twelfth group of positive electrode sheets is set as follows: A1=80%、A2=80%、A3=80%、A4=80%、A5=80%、A6=80%、A7=80%、A8=80%、A9=80%、The experimental results are as follows: The highest temperature 146.05℃, the lowest temperature is 73.681℃, the temperature difference is 72.369℃, the opening rate of the thirteenth group of positive electrode sheets is set as: A1=90%, A2=90%, A3=90%, A4=90%, A5=90%, A6=90%, A7=90%, A8=90%, A9=90%, the experimental measurement results are: the highest temperature is 300.67℃, the lowest temperature is 102.5℃, and the temperature difference is 198.17℃. .

[0038] like Figure 6As shown, different opening ratio combinations are selected for the negative electrode sheets in different regions to measure the temperature difference. The opening ratio of the first group of negative electrode sheets is set as: A1=0%, A2=0%, A3=0%, A4=0%, A5=0%, A6=10%, A7=0%, A8=0%, A9=0%. The experimental measurement results are: the highest temperature is 43.131°C, the lowest temperature is 36.746°C, and the temperature difference is 6.385°C. The opening ratio of the second group of negative electrode sheets is set as: A1=5%, A2=5%, A3=5%, A4=5%, A5=5%, A6=5%, A7=5%, A8=5%, A9=5%. The experimental measurement results are: the highest temperature is 43.426°C, the lowest temperature is 39.779°C, and the temperature difference is 6.385°C. The temperature difference is 3.647℃, the third group of opening rates of the negative electrode sheet is set to: A1=10%, A2=10%, A3=10%, A4=10%, A5=10%, A6=10%, A7=10%, A8=10%, A9=10%, the experimental measurement results are: the highest temperature is 45.006℃, the lowest temperature is 38.715℃, the temperature difference is 6.291℃, the fourth group of opening rates of the negative electrode sheet is set to: A1=10%, A2=10%, A3=10%, A4=10%, A5=10%, A6=10%, A7=10%, A8=10%, A9=20%, the experimental measurement results are: the highest temperature is 45.047℃, the lowest temperature is 39.008℃, the temperature difference The fifth group of opening rates of the negative electrode sheet is set to 6.039°C, and the opening rates of the fifth group of negative electrode sheets are set to: A1=10%, A2=10%, A3=10%, A4=10%, A5=10%, A6=10%, A7=10%, A8=20%, A9=20%. The experimental results are: the highest temperature is 45.131°C, the lowest temperature is 39.714°C, and the temperature difference is 5.417°C. The sixth group of opening rates of the negative electrode sheet is set to: A1=10%, A2=10%, A3=10%, A4=10%, A5=10%, A6=10%, A7=10%, A8=20%, A9=30%. The experimental results are: the highest temperature is 45.187°C, the lowest temperature is 39.976°C, and the temperature difference is 5.211℃, the seventh group of opening rates of the negative electrode sheet is set as: A1 = 10%, A2 = 10%, A3 = 10%, A4 = 10%, A5 = 10%, A6 = 10%, A7 = 20%, A8 = 20%, A9 = 30%, the experimental measurement results are: the highest temperature is 45.269℃, the lowest temperature is 40.144℃, and the temperature difference is 5.125℃. The eighth group of opening rates of the negative electrode sheet is set as: A1 = 10%, A2 = 10%, A3 = 10%, A4 = 10%, A5 = 10%, A6 = 20%, A7 = 20%, A8 = 20%, A9 = 30%, the experimental measurement results are: the highest temperature is 45.394℃, the lowest temperature is 40.252℃, and the temperature difference is 5.142℃, the ninth group of opening rates of the negative electrode sheet are set to: A1=10%, A2=10%, A3=10%, A4=10%, A5=20%, A6=20%, A7=20%, A8=20%, A9=30%, the experimental measurement results are: the highest temperature is 45.442℃, the lowest temperature is 40.756℃, the temperature difference is 4.686℃, the tenth group of opening rates of the negative electrode sheet are set to: A1=10%, A2=10 %, A3=10%, A4=10%, A5=20%, A6=20%, A7=20%, A8=30%, A9=40%. The experimental results are as follows: the highest temperature is 45.489℃, the lowest temperature is 41.711℃, the temperature difference is 3.778℃, and the opening rate of the eleventh group of negative electrode sheets is set as: A1=10%, A2=10%, A3=10%, A4=10%, A5=20%, A6=20%, A7=20%, A8=30%, A9=40%. 7=20%、A8=30%、A9=50%. The experimental results are as follows: the highest temperature is 46.221℃, the lowest temperature is 43.08℃, the temperature difference is 3.141℃. The opening rate of the twelfth group of negative electrode sheets is set as follows: A1=80%、A2=80%、A3=80%、A4=80%、A5=80%、A6=80%、A7=80%、A8=80%、A9=80%. The experimental results are as follows: the highest temperature is 46.221℃, the lowest temperature is 43.08℃, the temperature difference is 3.141℃. The opening rate of the twelfth group of negative electrode sheets is set as follows: A1=80%、A2=80%、A3=80%、A4=80%、A5=80%、A6=80%、A7=80%、A8=80%、A9=80%. 117.28℃, the lowest temperature is 79.629℃, the temperature difference is 37.651℃, the opening rate of the thirteenth group of negative electrode plates is set as: A1=90%, A2=90%, A3=90%, A4=90%, A5=90%, A6=90%, A7=90%, A8=90%, A9=90%, the experimental measurement results are: the highest temperature is 213.55℃, the lowest temperature is 114.08℃, and the temperature difference is 99.47℃. .

[0039] Depend on Figure 5 , Figure 6It can be seen that the highest temperature of the general positive electrode sheet under working conditions is 40.58℃, the lowest temperature of the general positive electrode sheet under working conditions is 37.528℃, the maximum temperature difference of the general positive electrode sheet under working conditions is 3.052℃, the highest temperature of the positive electrode sheet with holes in the length direction is 42.579℃, the lowest temperature of the positive electrode sheet with holes in the length direction is 41.16℃, the maximum temperature difference of the positive electrode sheet with holes in the length direction under working conditions is 1.419℃, the highest temperature of the general negative electrode sheet under working conditions is 43.131℃, and the general negative electrode The lowest temperature of the electrode under working condition is 36.746℃, the maximum temperature difference of general negative electrode under working condition is 6.385℃, the highest temperature of negative electrode with holes in different areas in length direction is 46.221℃, the lowest temperature of negative electrode with holes in different areas in length direction is 43.08℃, the maximum temperature difference of negative electrode with holes in different areas in length direction under working condition is 3.141℃. The general electrode described here is an unperforated electrode. Under working condition, the temperature distribution of electrode with holes in different areas in length direction is the smallest compared with that of ordinary electrode with holes and general electrode.

[0040] In this embodiment, Figure 5 It can be seen that the opening rate of the area of ​​the positive electrode sheet is:

[0041] When A1=A2=A3=A4=A5=A6=10%,A7=A8=20%,A9=40%,the temperature difference is the smallest and the temperature distribution is more uniform. Figure 6 It can be seen that when the opening rate of the area of ​​the negative electrode sheet is:

[0042] When A1=A2=A3=A4=10%, A5=A6=A7=A8=20%, A8=30%, A9=50%, the temperature difference is the smallest. In the above comparison between the general electrode and the common hole electrode, whether the electrode has holes is a single variable. In the comparison between the common hole electrode and the electrode with holes in the length direction, whether the holes are in the length direction is a single variable. Figure 5 and Figure 6 The opening ratio is taken as a single variable.

[0043] Optionally, along the length direction, the porosity of each region increases successively, that is, in the direction from the pole ear to the pole piece body, the porosity An of the latter region is greater than the porosity A(n-1) of the former region.

[0044] Optionally, through holes 2 are set in the area, and there is no limitation on the shape and distribution of the through holes 2. The through holes 2 can be set to be circular, square or other shapes, and the through holes 2 can be set to be distributed equidistantly or according to other rules or irregular arrangements.

[0045] The present application provides a pole core, including a pole piece of any of the above-described embodiments, by arranging regional openings in the pole core, the opening rate is A(n-1)≤An and there is at least one pole piece with A(n-1)<An, thereby improving the heat generation uniformity of the pole core in the working state and reducing the mass of the pole core.

[0046] The present application provides a battery, comprising a pole core according to any one of the above-mentioned embodiments.

[0047] The present application provides a battery device, comprising the battery of any one of the above embodiments.

[0048] Specifically, the battery device of the present application refers to a device that can convert the chemical energy stored in itself into electrical energy, that is, a device that converts the pre-stored energy into electrical energy for external use. The battery device can be charged and store electrical energy, and can also be discharged to power other external devices. It is understood that the battery storage device may include but is not limited to a battery pack, a battery module or a battery system.

[0049] Specifically, the electric device disclosed in the present application includes the battery device described above. The electric device may be, but is not limited to, a mobile phone, a tablet, a laptop, an electric toy, an electric tool, a battery car, an electric car, a ship or a spacecraft, etc. Among them, the electric toy may include a fixed or mobile electric toy, for example, a game console, an electric car toy, an electric ship toy and an electric airplane toy, etc., and the spacecraft may include an airplane (including a drone), a rocket, a space shuttle and a spacecraft, etc.

[0050] In summary, the embodiments of the utility model provide a pole piece 1, a pole core, a battery, a battery device and an electrical equipment, which can effectively solve the problem of uneven heating of the pole piece, that is, solve the problem that the pole piece mass distribution is not reasonable, which is not conducive to improving the fast charging performance of the battery and extending the battery cycle life.

[0051] Obviously, the above embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention, and are not intended to limit the implementation methods of the present invention. For those skilled in the art, various obvious changes, readjustments and substitutions can be made without departing from the scope of protection of the present invention. It is not necessary and impossible to list all implementation methods here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention shall be included in the scope of protection of the claims of the present invention.

Claims

1. A pole piece, characterized in that: The pole piece includes a pole ear and a pole piece body, wherein the pole ear is connected to one end of the pole piece body along the length direction, and along the length direction, the pole piece body is provided with a plurality of regions arranged in sequence, each of the regions has the same area, and each of the regions is provided with a through hole; Along the length direction, the ratio of the total area of ​​the through holes in each region to the total area of ​​the corresponding region is the opening rate, which is recorded as A. The region closest to the tab is set as the first region, and the opening rate of the first region is recorded as A1. The region adjacent to the first region is set as the second region, and the opening rate of the second region is recorded as A2. By analogy, the opening ratio of the nth region is recorded as An, A(n-1)≤An and there is at least one A(n-1)<An.

2. The pole piece according to claim 1, characterized in that: 10％≤A≤80％。 3. The pole piece according to claim 1, characterized in that: The pole piece body is provided with 9 regions along the length direction.

4. The pole piece according to claim 3, characterized in that: The porosity of each of the areas is: A1=A2=A3=A4=A5=A6=10%, A7=A8=20%, A9=40%, or the porosity of each of the areas is: A1=A2=A3=A4=10%, A5=A6=A7=A8=20%, A8=30%, A9=50%.

5. The pole piece according to claim 1, characterized in that: Along the length direction, the opening rate of each region increases successively.

6. The pole piece according to any one of claims 1 to 5, characterized in that: The plurality of through holes are arranged regularly or irregularly.

7. The pole piece according to any one of claims 1 to 5, characterized in that: Each of the regions is provided with a plurality of through holes, and the plurality of through holes have the same aperture.

8. The pole piece according to any one of claims 1 to 5, characterized in that: The shapes of the plurality of through holes are respectively circular and / or polygonal.

9. A pole core, characterized in that: It comprises a pole piece as claimed in any one of claims 1 to 8.

10. A battery, characterized in that: Including the pole core as described in claim 9.

11. A battery device, characterized in that: Comprising the battery as claimed in claim 10.

12. An electrical equipment, characterized in that: Comprising the battery as claimed in claim 10 or the battery device as claimed in claim 11.

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