Pole piece, pole core, battery and vehicle

Abstract

The utility model relates to the field of batteries, and discloses a pole piece, a pole core, a battery and a vehicle. The pole piece comprises a current collector. And the active material layer is arranged on the surface of the current collector, and the surface, deviating from the current collector, of the active material layer is provided with an opening area and a first diversion trench. Wherein the opening area is provided with a plurality of permeation holes, the number of the first flow guide grooves is at least two, at least one first flow guide groove penetrates through the opening area, the two ends of the first flow guide groove are formed in the two opposite edges of the active substance layer respectively, and the permeation holes are formed in the opening area and the two sides of the first flow guide groove. The first diversion trench penetrates through the opening area and extends to the edge of the active substance layer, so that the first diversion trench has good diversion and guiding effects on the electrolyte relative to the permeation hole, and equivalently, an electrolyte conduction channel from the edge of the pole piece to the opening area is increased.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of battery, concretely relates to pole piece, pole core, battery and vehicle. BACKGROUND

[0002] With the rapid development of modern science and technology, lithium ion batteries have shown great application potential in many fields such as portable electronic devices, electric vehicles and energy storage systems due to their high energy density, long cycle life and environmental friendliness.

[0003] In the structure of lithium batteries, the pole piece is one of the core components, and its performance is directly related to the overall performance of the battery. The wettability of the pole piece refers to the ability of the electrolyte to effectively penetrate into the pores of the pole piece. Good wettability can ensure that the active material and the electrolyte are in full contact, thereby reducing the polarization resistance and improving the charge and discharge efficiency of the battery, especially the fast charging and discharging capacity. In order to improve the wettability of the pole piece, the related technology adopts the method of punching holes in the active material layer of the pole piece to speed up the diffusion speed of the electrolyte inside the pole piece, thereby improving the wettability efficiency.

[0004] However, the central region of the pole piece still has uneven wettability, which not only limits the further improvement of the fast charging performance of the battery, but also may affect the safety and cycle stability of the battery due to local overheating and polarization aggravation. SUMMARY

[0005] Therefore, the utility model provides a kind of pole piece, pole core, battery and vehicle to solve or improve the problem of poor wettability in the central region of pole piece.

[0006] In a first aspect, the utility model provides a kind of pole piece, comprising:

[0007] current collector;

[0008] active material layer, set in the surface of the current collector, the surface of the active material layer away from the current collector is provided with opening area and first flow guide groove;

[0009] Wherein, the opening area is provided with a plurality of penetration holes, the number of the first flow guide groove is at least two, at least one first flow guide groove passes through the opening area, and the two ends of the first flow guide groove are respectively arranged at the two edges of the active material layer opposite, and the penetration hole is arranged on both sides of the first flow guide groove in the opening area.

[0010] In an alternative embodiment, in the extension direction of the first flow guide groove, at least one side of the opening area has a spacing between the corresponding edge of the active material layer.

[0011] In an alternative embodiment, the ratio of the size of the opening region to the size of the active material layer in the extension direction of the first flow channel ranges from 15% to 80%.

[0012] In an alternative embodiment, the ratio of the depth of the penetration hole to the thickness of the active material layer is greater than or equal to 40%;

[0013] And / or, the ratio of the depth of the first flow channel to the thickness of the active material layer is less than or equal to 50%.

[0014] In an alternative embodiment, the pole piece further comprises a tab;

[0015] Wherein, in the extension direction of the first flow channel, the tab is arranged at the edge of one side of the current collector, or, in the direction intersecting the extension direction of the first flow channel, the tab is arranged at the edge of one side of the current collector.

[0016] In an alternative embodiment, the surface of the active material layer away from the current collector is provided with a second flow channel, the second flow channel intersects the first flow channel, and at least one side of the second flow channel is provided with the penetration hole.

[0017] In an alternative embodiment, the percentage of active material lost by the active material layer opening the penetration hole and the first flow channel ranges from 0 to 5%;

[0018] And / or, the diameter of the penetration hole ranges from 20 μm to 1000 μm;

[0019] And / or, the distance between adjacent penetration holes ranges from 0.1 mm to 4 mm;

[0020] And / or, the width of the first flow channel ranges from 10 μm to 200 μm;

[0021] And / or, the distance between adjacent first flow channels ranges from 0.1 mm to 10 mm.

[0022] Secondly, the utility model further provides a pole core, including positive pole piece, negative pole piece and diaphragm;

[0023] Wherein, the diaphragm is arranged between the positive pole piece and the negative pole piece, and the negative pole piece is arranged as the pole piece.

[0024] Thirdly, the utility model further provides a battery, including the pole piece or the pole core.

[0025] In a fourth aspect, the utility model also provides a kind of vehicle, including the pole piece as described above, the pole core as described above or the battery as described above.

[0026] The pole piece provided by the utility model provides additional electrolyte infiltration channels on the active material layer, shortens the conduction distance of electrolyte into the bottom of the active material layer, and improves the infiltration effect of electrolyte on the pole piece.

[0027] By making the first flow guide groove pass through the opening area and extend to the edge of the active material layer, the first flow guide groove has a good flow guide and guiding effect on electrolyte relative to the penetration hole, which is equivalent to increasing the electrolyte conduction channel from the edge of the pole piece to the opening area. For example, the opening area can be arranged in the central region of the pole piece, and the opening area substantially corresponds to the central region of the battery cell.

[0028] By making the first flow guide groove pass through the opening area, and the penetration hole is arranged on both sides of the first flow guide groove, the first flow guide groove can directly conduct electrolyte to the edge of the penetration hole on both sides of the first flow guide groove, so that each first flow guide groove can simultaneously supply electrolyte to more penetration holes, thereby ensuring the electrolyte supply efficiency of the opening area and improving the infiltration effect.

[0029] The pole core, the battery and the vehicle provided by the utility model contain the pole piece provided by the utility model, and therefore contain all the advantages of the pole piece. BRIEF DESCRIPTION OF DRAWINGS

[0030] In order to more clearly illustrate the specific embodiments of the utility model or the technical solutions in the prior art, the following will briefly introduce the drawings needed to be used in the specific embodiments or the prior art description. Obviously, the drawings described below are some embodiments of the utility model, and those skilled in the art can also obtain other drawings according to these drawings without creative labor.

[0031] Figure 1 A structure diagram of a pole piece provided by the embodiment of the utility model is shown in the figure.

[0032] Figure 2 Another structure diagram of a pole piece provided by the embodiment of the utility model is shown in the figure.

[0033] Figure 3 Another structure diagram of a pole piece provided by the embodiment of the utility model is shown in the figure.

[0034] Figure 4 A sectional view of the pole piece provided by the embodiment of the utility model is shown in the figure.

[0035] MARKED EXPLANATION OF DRAWINGS:

[0036] 100. pole piece; 1. current collector; 2. active material layer; 201. opening region; 2011. penetration hole; 202. first flow guide groove; 203. second flow guide groove; 3. tab. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical scheme and advantages of the embodiments of the utility model clearer, the technical scheme in the embodiments of the utility model will be described clearly and completely in combination with the drawings in the embodiments of the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by the person skilled in the art without creative labor belong to the protection scope of the utility model.

[0038] In order to improve the infiltration of the pole piece, the related technology adopts the way of punching on the active material of the pole piece to accelerate the diffusion speed of the electrolyte in the pole piece, thereby improving the infiltration efficiency.

[0039] However, the central region of the pole piece is far away from the edge, the electrolyte penetration path is relatively long and complex, and in addition, the region is subjected to stronger extrusion during the swelling process of the battery cell, so that the uneven infiltration phenomenon is more significant. This not only limits the further improvement of the fast charging performance of the battery, but also may affect the safety and cycle stability of the battery due to local overheating, polarization aggravation and other problems.

[0040] The embodiments of the utility model will be described below in combination with Figures 1 to 4 The pole piece 100 provided in the embodiments of the utility model.

[0041] Specifically, the pole piece 100 includes a current collector 1 and an active material layer 2.

[0042] Among them, the current collector 1 can be set as a metal foil, for example, when the pole piece 100 is a negative pole piece, the metal foil is a copper foil.

[0043] The active material layer 2 is arranged on the surface of the current collector 1, for example, the active material layer 2 can be formed by the active material slurry coated on the surface of the current collector 1. The surface of the active material layer 2 away from the current collector 1 is provided with an opening region 201 and a first flow guide groove 202.

[0044] Among them, the opening region 201 is provided with a plurality of penetration holes 2011. Optionally, the penetration hole 2011 can be laser punched, or the penetration hole 2011 is formed by a roller shaft or a flat plate cold pressing provided with a protrusion on the surface. Optionally, the geometric center of the pole piece 100 falls into the opening region 201.

[0045] The number of the first flow guide grooves 202 is at least two. Optionally, the first flow guide grooves 202 can be formed by laser slotting, or the first flow guide grooves 202 are formed by cold pressing of rollers or flat plates provided with protrusions on the surface.

[0046] The at least one first flow guide groove 202 passes through the opening area 201, and two ends of the first flow guide groove 202 are respectively arranged at the opposite edges of the active material layer 2, so that the electrolyte can flow between the edges of the current collector 1 and the opening area 201 through the first flow guide groove 202. Optionally, at least one end of the first flow guide groove 202 penetrates the corresponding edge of the active material layer 2. On the opening area 201, both sides of the first flow guide groove 202 are provided with the penetration holes 2011.

[0047] For example, all the first flow guide grooves 202 pass through the opening area 201, and both sides of all the first flow guide grooves 202 are provided with the penetration holes 2011. Alternatively, part of the first flow guide grooves 202 pass through the opening area 201, and the other part of the first flow guide grooves 202 are distributed on one side or both sides of the opening area 201, so that for the first flow guide grooves 202 on one side of the opening area 201, one side of the first flow guide grooves 202 is provided with the penetration holes 2011.

[0048] In this embodiment, by arranging the opening area 201 on the active material layer 2, and providing a plurality of penetration holes 2011 in the opening area 201, an additional electrolyte infiltration channel is provided on the active material layer 2, the conduction distance of the electrolyte entering the bottom of the active material layer 2 is shortened, and the electrolyte infiltration effect on the pole piece 100 is improved.

[0049] By making the first flow guide groove 202 pass through the opening area 201 and extend to the edge of the active material layer 2, the first flow guide groove 202 has a good flow guide and guiding effect on the electrolyte relative to the penetration hole 2011, which is equivalent to increasing the electrolyte conduction channel from the edge of the pole piece 100 to the opening area 201. For example, the opening area 201 can be arranged in the central region of the pole piece 100, and the opening area 201 substantially corresponds to the central region of the battery cell.

[0050] By making the first flow guide groove 202 pass through the opening area 201, and both sides of the first flow guide groove 202 are provided with the penetration holes 2011, the first flow guide groove 202 can directly conduct the electrolyte to the edge of the penetration hole 2011 on both sides of the first flow guide groove 202, so that each first flow guide groove 202 can simultaneously supplement the electrolyte for more penetration holes 2011, thereby ensuring the electrolyte supplement efficiency of the opening area 201 and improving the infiltration effect.

[0051] When the electrode 100 is applied to the battery and is in the battery cycle process or late cycle stage, the electrode 100 expands and squeezes the separator, inhibiting the replenishment of electrolyte. This results in insufficient electrolyte in the central area of ​​the cell. The electrolyte can be replenished to the central area of ​​the cell through the first guide groove 202 and enter the interior of the electrode 100 through the permeation hole 2011, thereby improving the wetting of the electrode 100 and the concentration polarization of the cell, thus delaying capacity decay and improving fast charging cycle life.

[0052] In addition, the electrolyte in the central region of the battery cell can be conducted to the outside through the first guide channel 202, while the electrolyte outside can enter the central region of the battery cell through the first guide channel 202. In this way, through the exchange of electrolyte, the heat in the central region of the battery cell can be dissipated outward, reducing the temperature rise of the battery cell body and reducing side reactions.

[0053] like Figure 1 As shown, in some embodiments of this utility model, the first guide channel 202 can be a straight structure, with its two ends respectively located at the two opposite edges of the active material layer 2. This design simplifies the structure of the first guide channel 202, making it easier to manufacture, and shortens the flow path of the first guide channel 202, thereby increasing the rate at which the first guide channel 202 transmits electrolyte.

[0054] Of course, the first guide channel 202 is not limited to being a straight structure.

[0055] For example, in some embodiments not shown, the whole structure can also be a curved structure, a broken line structure or a wave-shaped structure. For the first guide groove 202 which is set as a curved structure, a broken line structure or a wave-shaped structure, its two ends are respectively set at two opposite edges of the active material layer 2. That is, the whole first guide groove 202 extends from one edge of the active material layer 2 to the other edge, so its extension direction is from one edge to the other opposite edge.

[0056] In this embodiment, by setting the first guide channel 202 as a curved structure, a broken line structure or a wave-shaped structure, the length of the first guide channel 202 can be extended, so that the first guide channel 202 itself can also accommodate or store more electrolyte, thereby improving the problem of insufficient electrolyte in the later stage of battery cycling.

[0057] like Figure 1 As shown, in some embodiments provided by this utility model, in the opening area 201, multiple permeation holes 2011 are provided on both sides of the first guide groove 202, and on any side of the first guide groove 202, the multiple permeation holes 2011 are distributed along the extension direction of the first guide groove 202.

[0058] In the embodiment, the first flow guide groove 202 can more efficiently supply electrolyte to each penetration hole 2011 when conducting electrolyte. For example, during the charging and discharging process of the battery, the electrolyte will be consumed to a certain extent, and the arrangement of the penetration holes 2011 along the first flow guide groove 202 can ensure that each penetration hole 2011 can stably obtain sufficient electrolyte when it needs to be replenished.

[0059] Referring to Figure 1 and Figure 2 As shown in FIGS. 1, 2, and 3, in some embodiments of the present application, the number of first flow guide grooves 202 passing through the opening area 201 is multiple, and the multiple first flow guide grooves 202 are arranged in sequence along the direction perpendicular to the extension direction of the first flow guide groove 202, and both sides of each first flow guide groove 202 are distributed with penetration holes 2011.

[0060] In the embodiment, by arranging multiple first flow guide grooves 202 and arranging the first flow guide grooves 202 side by side, the multiple first flow guide grooves 202 can jointly convey electrolyte to the penetration holes 2011 of the opening area 201, so that the multiple penetration holes 2011 of the opening area 201 can uniformly obtain electrolyte, and the uniformity of electrolyte distribution is improved.

[0061] Referring to Figure 1 and Figure 2 As shown in FIGS. 1, 2, and 3, in some embodiments of the present application, in the extension direction of the first flow guide groove 202, there is a gap between at least one side of the opening area 201 and the corresponding edge of the active material layer 2. For example, Figure 1 and Figure 2 As shown in FIGS. 1, 2, and 3, in some embodiments of the present application, in the extension direction of the first flow guide groove 202, there is a gap between at least one side of the opening area 201 and the corresponding edge of the active material layer 2. For example,

[0062] In the embodiment, since the edge of the active material layer 2 is more convenient to contact the electrolyte, the edge has a relatively good wetting effect, so it is not necessary to arrange too many penetration holes 2011 at the edge of the active material layer 2, thereby reducing the number of penetration holes 2011 on the surface of the active material layer 2, and reducing the processing difficulty and processing cost of the pole piece 100.

[0063] In addition, if the opening area 201 directly extends to the edge of the pole piece 100, the penetration hole 2011 can become an entrance for stress or corrosion factors, thereby damaging the edge structure of the active material layer 2, and arranging a gap between the opening area 201 and the edge can reduce the adverse effects of external factors on the edge part of the pole piece 100.

[0064] In addition, after the electrolyte enters the active material layer 2 from the flow guide groove or the penetration hole 2011, the electrolyte needs to be diffused in the entire active material layer 2. If the opening area 201 is close to the edge, the electrolyte can be diffused to the edge too quickly, resulting in insufficient distribution of the electrolyte in the central region of the active material layer 2. With the spacing, the electrolyte can be diffused in the central region of the active material layer 2 and the region close to the opening area 201 first, and then gradually permeate to the edge region, so that more uniform distribution is achieved.

[0065] In some embodiments provided by the utility model, in the extension direction of the first flow guide groove 202, the ratio of the size of the opening area 201 to the size of the active material layer 2 ranges from 15% to 80%. For example, the ratio of the size of the opening area 201 to the size of the active material layer 2 ranges from 15%, 20%, 30%, 40%, 50%, 60%, 70% or 80%. Corresponding to the drawings Figure 1 , the extension direction of the first flow guide groove 202 is the vertical direction in the drawings, that is, in the vertical direction, the ratio of the size of the opening area 201 to the size of the active material layer 2 ranges from 15% to 80%.

[0066] Reference Figure 1 It can be understood that the size of the active material layer 2 is also the size of the current collector, that is, the size of the tab without the lug.

[0067] In the embodiment, if the ratio of the size of the opening area 201 to the size of the active material layer 2 is less than 15%, the uniformity of the electrolyte infiltration effect is poor. If the ratio of the size of the opening area 201 to the size of the active material layer 2 is greater than 80%, the opening area 201 is too close to the edge of the active material layer 2, which can easily cause adverse effects on the edge of the active material or cause the electrolyte to spread too quickly to the edge.

[0068] Therefore, the ratio of the size of the opening area 201 to the size of the active material layer 2 ranges from 15% to 80%, which can not only ensure the uniform distribution of the electrolyte in the central region of the tab 100 and improve the infiltration effect of the middle part of the tab 100, but also avoid adverse effects on the edge of the active material layer 2.

[0069] In some embodiments provided by the utility model, the ratio of the depth of the penetration hole 2011 to the thickness of the active material layer 2 is greater than or equal to 40%. For example, the ratio of the depth of the penetration hole 2011 to the thickness of the active material layer 2 is 40%, 50%, 60%, 70%, 80%, 90% or 100%.

[0070] In the embodiment, when the penetration hole 2011 reaches a depth of 40% or more of the thickness of the active material layer 2, the electrolyte can penetrate into the inside of the active material layer 2, and is closer to the bottom part of the active material layer 2, thereby better wetting the entire active material layer 2. In addition, the deeper penetration hole 2011 can accommodate more electrolyte, thereby helping to maintain the concentration balance of the electrolyte during the operation of the battery.

[0071] In addition, unlike the first flow guide groove 202, the penetration hole 2011 does not cause large-scale cutting of the active material layer 2, and thus has less impact on the structural stability of the active material layer 2, so that the depth of the penetration hole 2011 can be greater than the depth of the first flow guide groove 202, so as to shorten the conduction distance of the electrolyte to the bottom of the active material layer 2, and improve the wetting effect of the center area of the tab 100.

[0072] If the depth of the penetration hole 2011 does not reach 40% of the thickness of the active material layer 2, the electrolyte will mainly concentrate in the upper part of the active material layer 2, causing uneven distribution of the electrolyte in the active material layer 2.

[0073] In some embodiments provided by the utility model, the ratio of the depth of the first flow guide groove 202 to the thickness of the active material layer 2 is less than or equal to 50%. For example, the ratio of the depth of the first flow guide groove 202 to the thickness of the active material layer 2 is 50%, 45%, 40%, 35%, 30%, 25%, 20%, 15%, 10%, 5%, 3% or 1%.

[0074] In the embodiment, when the depth of the flow guide groove is controlled within 50% of the thickness of the active material layer 2, most of the structure of the active material layer 2 is kept intact in the depth direction of the flow guide groove, thereby helping to prevent the active material layer 2 from breaking, delaminating and the like.

[0075] In addition, the depth of the flow guide groove is moderate, and the electrolyte will not excessively concentrate at the bottom of the flow guide groove due to excessive depth, so that the electrolyte can be distributed more evenly in the active material layer 2 through the flow guide groove and the surrounding penetration hole 2011, and the conduction of the electrolyte from the flow guide groove to the penetration hole 2011 is facilitated.

[0076] If the depth of the flow guide groove exceeds 50% of the thickness of the active material layer 2, the bottom structure of the active material layer 2 is excessively weakened, thereby causing the active material layer 2 to be prone to breaking, delaminating or falling off, and affecting the service life of the battery.

[0077] Reference Figure 1 As shown in some embodiments provided by the utility model, the tab 100 further comprises a tab lug 3.

[0078] As shown in FIG. 1, the first flow guide groove 202 extends in the vertical direction of the drawing, and the tab 3 is arranged at the edge of the upper end of the current collector 1. Figure 1 As shown in FIG. 1, the first flow guide groove 202 extends in the vertical direction of the drawing, and the tab 3 is arranged at the edge of the upper end of the current collector 1.

[0079] In this embodiment, the tab 3 is arranged at the edge of one side of the current collector 1 in the extension direction of the first flow guide groove 202, so that the tab 100 is particularly suitable for use in a wound battery, and of course can also be used in a stacked battery.

[0080] Specifically, as shown in FIG. 1, the tab 3 is arranged at the edge of the upper end of the current collector 1 in the extension direction of the first flow guide groove 202. Figure 2 As shown in FIG. 1, when the tab 100 is wound, the left and right sides of the tab 100 are wound inside the battery, and the upper and lower ends of the tab 100 are provided with the tab 3 and thus remain open. The electrolyte cannot be supplemented from the left and right sides of the tab 100, but can only be supplemented to the central region of the tab 100 from the upper and lower ends of the tab 100. Specifically, the electrolyte enters the first flow guide groove 202 from the edge of the upper and lower ends of the tab 100 and can be transported to the opening region 201 by the first flow guide groove 202.

[0081] Of course, the tab 3 is not limited to the above arrangement.

[0082] For example, as shown in FIG. 1, in other embodiments provided by the utility model, the tab 3 is arranged at the edge of one side of the current collector 1 in a direction intersecting the extension direction of the first flow guide groove 202. Optionally, as shown in FIG. 1, the extension direction of the first flow guide groove 202 is the vertical direction of the drawing, and the direction intersecting the vertical direction can be the horizontal direction, that is, along the horizontal direction, the tab 3 is arranged at the edge of the left side or the right side of the current collector 1. In this way, the tab 100 is more suitable for use in a stacked battery. Figure 2 Figure 2 As shown in FIG. 1, the extension direction of the first flow guide groove 202 is the vertical direction of the drawing, and the direction intersecting the vertical direction can be the horizontal direction, that is, along the horizontal direction, the tab 3 is arranged at the edge of the left side or the right side of the current collector 1. In this way, the tab 100 is more suitable for use in a stacked battery.

[0083] In some embodiments provided by the utility model, the active material layer 2 is provided with a second flow guide groove 203 away from the surface of the current collector 1.

[0084] As shown in FIG. 1, the second flow guide groove 203 intersects the first flow guide groove 202, and at least one side of the second flow guide groove 203 is provided with a permeable hole 2011. Optionally, the second flow guide groove 203 is perpendicular to the first flow guide groove 202. Optionally, the two ends of the second flow guide groove 203 are arranged at the opposite two edges of the active material layer 2, respectively.

[0085] In this embodiment, the second flow guide groove 203 intersecting the first flow guide groove 202 is arranged on the surface of the active material layer 2, so that the surface of the active material layer 2 forms a longitudinal and transverse intersecting electrolyte flow guide network, which can effectively avoid the accumulation of electrolyte in a local region, and make the distribution of electrolyte in the active material layer 2 more uniform. ​

[0086] The second flow guide groove 203 intersects the first flow guide groove 202 and the penetration hole 2011, so that the transmission path of the electrolyte is more diversified and short, thereby facilitating efficient replenishment of the electrolyte.

[0087] The second flow guide groove 203 and the first flow guide groove 202 can replenish the electrolyte to the opening area 201 in different directions, which can improve the stability and reliability of the electrolyte supply. For example, when the electrolyte replenished by one of the second flow guide groove 203 and the first flow guide groove 202 is insufficient, the other can continue to replenish the electrolyte to the opening area 201, thereby improving the reliability and durability of the battery.

[0088] Optionally, the number of the second flow guide groove 203 can be at least two, and the at least two second flow guide grooves 203 are arranged side by side, for example, the at least two second flow guide grooves 203 are arranged in sequence along the extension direction of the first flow guide groove 202.

[0089] Optionally, the second flow guide groove 203 can pass through the opening area 201, thereby better replenishing the electrolyte to the penetration hole 2011 of the opening area 201.

[0090] Reference Figure 1 and Figure 2 As shown in the drawings, in some embodiments provided by the present application, the plurality of penetration holes 2011 of the opening area 201 are arranged in rows and columns along the length and width direction of the pole piece 100.

[0091] In the present embodiment, the penetration holes 2011 arranged in rows and columns have clear position and spacing standards in the manufacturing process. In the punching operation of the pole piece 100, high-precision molds or automated equipment can be used to punch according to the pre-set row and column spacing, which helps to improve the production efficiency and the consistency of product quality, and reduce the production difficulty of the pole piece 100.

[0092] In some embodiments provided by the present application, the percentage of the active material lost by the penetration hole 2011 and the first flow guide groove 202 in the active material layer 2 is in the range of 0-5%. For example, the percentage of the active material lost is 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5% or 5%.

[0093] For example, the volume of the penetration hole 2011 can be calculated by the aperture and depth of the penetration hole 2011, and the amount of the active material lost by the opening can be calculated based on the volume of the penetration hole 2011 and the number of the penetration hole 2011.

[0094] Similarly, the volume of the first flow guide groove 202 can be calculated based on the groove depth, groove width and length of the first flow guide groove 202, and the amount of active substance lost by the grooving can be calculated based on the volume of the first flow guide groove 202 and the number of the first flow guide grooves 202.

[0095] The amount of active substance lost by the grooving and the perforating is compared with the initial amount of active substance of the active substance layer 2, and the percentage of active substance lost by the active substance layer 2 due to the penetration holes 2011 and the first flow guide grooves 202 can be calculated.

[0096] In this embodiment, the percentage of active substance lost by the active substance layer 2 is controlled in the range of 0-5%, so that the battery can maintain a high energy density, thereby maintaining the normal working voltage and capacity of the battery, and the battery can provide stable power output.

[0097] In addition, controlling the loss percentage can effectively slow down the speed of battery capacity decline, which helps to prolong the cycle life of the battery, so that the battery can still maintain good performance after being charged and discharged for many times.

[0098] Alternatively, if the penetration holes 2011 and the first flow guide grooves 202 are formed by cold pressing, the percentage of active substance lost by the active substance layer 2 is zero.

[0099] In some embodiments of the present application, the diameter of the penetration hole 2011 ranges from 20 μm to 1000 μm. For example, the diameter of the penetration hole 2011 is 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm, 150 μm, 200 μm, 250 μm, 300 μm, 350 μm, 400 μm, 450 μm, 500 μm, 550 μm, 600 μm, 650 μm, 700 μm, 750 μm, 800 μm, 850 μm, 900 μm, 950 μm or 1000 μm.

[0100] In this embodiment, when the diameter of the penetration hole 2011 is in the range of 20 μm to 1000 μm, a suitable channel can be provided for the electrolyte, so that the electrolyte can smoothly pass through the penetration hole 2011 into the inside of the active substance layer 2, and the structural strength of the active substance layer 2 is ensured, preventing the problem of loose structure of the active substance layer 2 due to too large holes.

[0101] If the diameter is less than 20 μm, the diffusion of electrolyte molecules therein will be greatly limited, and the processing difficulty of the penetration hole 2011 is great, so that the processing cost of the pole piece 100 is high.

[0102] While diameters greater than 1000 μm, although conducive to the rapid passage of electrolyte, can compromise the structural integrity of the active material layer 2.

[0103] In some embodiments provided by the utility model, the interval of the adjacent permeable holes 2011 is 0.1mm-4mm. For example, the interval of the adjacent permeable holes 2011 is 0.1mm, 0.2mm, 0.5mm, 0.7mm, 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm or 4mm. The interval of the permeable holes 2011 can refer to the center distance of the permeable holes 2011. For the permeable holes 2011 arranged in rows and columns, the interval of the permeable holes 2011 in each row or column is 0.1mm-4mm.

[0104] In the embodiment, when the interval of the adjacent permeable holes 2011 is 0.1mm-4mm, the structure of the active material layer 2 can be avoided from being destroyed due to the too dense permeable holes 2011, that is, the active material can maintain sufficient connection and maintain the overall structural stability of the active material layer 2. And the electrolyte can realize good diffusion in the active material layer 2.

[0105] If the interval of the permeable holes 2011 is less than 0.1mm, the density of the permeable holes 2011 is too large, which is easy to cause the fragile structure of the active material layer 2 and reduce the mechanical strength, because too many holes will weaken the connection between the active materials.

[0106] If the interval of the permeable holes 2011 is greater than 4mm, it is easy to cause the electrolyte to be difficult to fully diffuse in the area between the permeable holes 2011, which may cause local electrolyte deficiency.

[0107] In some embodiments provided by the utility model, the width of the first flow guide groove 202 is 10μm-200μm. For example, the width of the first flow guide groove 202 is 10μm, 20μm, 30μm, 40μm, 50μm, 60μm, 70μm, 80μm, 90μm, 100μm, 110μm, 120μm, 130μm, 140μm, 150μm, 160μm, 170μm, 180μm, 190μm or 200μm.

[0108] In the embodiment, the width of the first flow guide groove 202 is 10μm-200μm, so that the first flow guide groove 202 has enough space to guide the electrolyte, so that the electrolyte can flow smoothly in the first flow guide groove 202. In addition, it can prevent the first flow guide groove 202 from occupying too much space in the active material layer 2, avoid the first flow guide groove 202 to excessively reduce the content of the active material, affect the energy density of the battery, and reduce the structural strength of the active material layer 2.

[0109] If the width of the first flow guide groove 202 is less than 10 μm, the width of the first flow guide groove 202 is too narrow, and a large flow resistance of the electrolyte is easily generated.

[0110] If the width of the first flow guide groove 202 is greater than 200 μm, the first flow guide groove 202 is too wide, and a large amount of space originally belonging to the active material is occupied, and the battery energy density is affected.

[0111] In some embodiments provided by the utility model, the interval between adjacent first flow guide grooves 202 is 0.1 mm to 10 mm. For example, the interval between adjacent first flow guide grooves 202 is 0.1 mm, 0.2 mm, 0.5 mm, 0.7 mm, 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm or 10 mm. Alternatively, the interval of the first flow guide groove 202 can refer to the center distance of the first flow guide groove 202.

[0112] In the embodiment, when the interval between adjacent first flow guide grooves 202 is 0.1 mm to 10 mm, the range can ensure that the electrolyte is uniformly distributed in the active material layer 2, avoid that the density of the first flow guide groove 202 is too large and a large amount of active material space is occupied, affect the battery energy density, and avoid that the first flow guide groove 202 is too sparse and the electrolyte in the active material layer 2 has sufficient flow guide channels.

[0113] If the interval between the first flow guide grooves 202 is less than 0.1 mm, the interval between the first flow guide grooves 202 is too small, and the electrolyte can be concentrated near the flow guide groove, resulting in insufficient supply of electrolyte in the area far from the flow guide groove. And it can cause the density of the first flow guide groove 202 to be too large, thereby occupying too much active material space.

[0114] If the interval between the first flow guide grooves 202 is greater than 10 mm, the first flow guide groove 202 is too sparse, and it is difficult to ensure sufficient flow guide channels.

[0115] In some embodiments provided by the utility model, as shown in Figure 4 The penetration hole 2011 can be provided as a conical hole, a circular truncated cone hole, a circular hole or a spherical hole.

[0116] In some embodiments provided by the utility model, as shown in Figure 4 The cross section of the first flow guide groove 202 can be provided as a triangle, a trapezoid, a rectangle or a circular arc.

[0117] In some embodiments of the utility model, the penetration hole 2011 is a conical hole, and the thickness of the single-sided active material layer 2 is 50 μm. The orifice diameter of the penetration hole 2011 is 100 μm, and the depth of the penetration hole 2011 is 50% of the thickness of the active material layer 2. The slot width of the first flow guide groove 202 is 150 μm, and the slot depth is 30% of the thickness of the active material layer 2. In the extension direction of the first flow guide groove 202, the ratio of the size of the opening area 201 to the size of the active material layer is 30%. On this basis, experiments are carried out, and the data in Table 1 are obtained.

[0118] Table 1

[0119]

[0120] It should be noted that " / " in Table 1 represents no relevant parameters. "1000 cls" means 1000 cycles, that is, 1000 cycles are performed.

[0121] The data numbered 1, 2 and 3 in Table 1 are all comparative examples, and the data corresponding to number 4 is an embodiment. Based on the data in Table 1, it can be known that the opening area 201 and the first flow guide groove 202 provided on the pole piece 100 can significantly inhibit the temperature rise of the battery cell, reduce the lithium precipitation of the battery cell, and prolong the fast charging cycle life of the battery cell.

[0122] In some embodiments of the utility model, the penetration hole 2011 is a conical hole, and the thickness of the single-sided active material layer 2 is 50 μm. The slot width of the first flow guide groove 202 is 150 μm, and the slot depth is 30% of the thickness of the active material layer 2, and the spacing of the first flow guide groove 202 is 1.2 mm. In the extension direction of the first flow guide groove 202, the ratio of the size of the opening area 201 to the size of the active material layer is 30%. On this basis, experiments are carried out, and the data in Table 2 are obtained.

[0123] Table 2

[0124]

[0125] It should be noted that " / " in Table 1 represents no relevant parameters. "500 cls" means 500 cycles, that is, 500 cycles are performed.

[0126] In some embodiments of the utility model, the penetration hole 2011 is a conical hole, and the thickness of the single-sided active material layer 2 is 50 μm. The orifice diameter of the penetration hole 2011 is 100 μm, and the depth of the penetration hole 2011 is 50% of the thickness of the active material layer 2, and the hole spacing is 0.4 mm. In the extension direction of the first flow guide groove 202, the ratio of the size of the opening area 201 to the size of the active material layer is 30%. On this basis, experiments are carried out, and the data in Table 3 are obtained.

[0127] Table 3

[0128]

[0129] In some embodiments of the utility model, the electrode sheet compaction is 1.55g / m3, the single side area density is 75g / m2, the cell group margin is 90%, and the electrode sheet full charge rebound is 14%~17%. The penetration hole 2011 is a conical hole, the orifice diameter of the penetration hole 2011 is 100μm, the depth of the penetration hole 2011 is 50% of the thickness of the active material layer 2, and the hole spacing is 0.4mm. The slot width of the first flow guide groove 202 is 150μm, the slot depth is 30% of the thickness of the active material layer 2, and the slot spacing is 1mm. On this basis, experiments are carried out, and the data in table 4 are obtained.

[0130] Table 4

[0131]

[0132]

[0133] In some embodiments of the utility model, the penetration hole 2011 is a conical hole, and the single side active material layer 2 thickness is 50μm. The orifice diameter of the penetration hole 2011 is 100μm, and the depth of the penetration hole 2011 is 50% of the thickness of the active material layer 2. The slot width of the first flow guide groove 202 is 150μm, and the slot depth is 30% of the thickness of the active material layer 2. In the extension direction of the first flow guide groove 202, the ratio of the size of the opening region 201 to the size of the active material layer is 30%. On this basis, experiments are carried out, and the data in table 5 are obtained.

[0134] Table 5

[0135]

[0136]

[0137] Referring to table 5, the numbers 1, 2 and 3 in table 5 are comparative examples, and the remaining numbers correspond to embodiments.

[0138] The utility model embodiment further provides a pole core.

[0139] Specifically, the pole core comprises a positive electrode sheet, a negative electrode sheet and a diaphragm.

[0140] The diaphragm is arranged between the positive electrode sheet and the negative electrode sheet, and the negative electrode sheet is arranged as the above electrode sheet 100.

[0141] It should be noted that the pole core includes the electrode sheet 100, and also includes all the advantages of the electrode sheet 100, so no further description is given.

[0142] In addition, the negative electrode will undergo lithium ion intercalation reaction during charging and lithium ion deintercalation reaction during discharging. During this process, ion transport and sufficient contact with electrolyte are crucial for the efficiency and stability of the negative electrode reaction.

[0143] By setting the opening area 201 and the flow guide groove in the negative electrode sheet, the wettability of the electrolyte in the negative electrode active material layer 2 can be optimized, more and shorter transport paths for lithium ions are provided, and the intercalation and deintercalation of lithium ions can be more smoothly carried out, thereby improving the efficiency of the negative electrode reaction, reducing the polarization phenomenon caused by insufficient electrolyte wettability or ion transport obstruction, and improving the charge and discharge performance of the battery.

[0144] The utility model embodiment further provides a battery.

[0145] Specifically, the battery comprises the electrode sheet 100 as above or the electrode core as above.

[0146] It should be noted that the battery comprises the electrode sheet 100, and therefore comprises all the advantages of the electrode sheet 100, which will not be repeated here.

[0147] The utility model embodiment further provides a vehicle.

[0148] Specifically, the vehicle comprises the electrode sheet 100 as above, the electrode core as above, or the battery as above.

[0149] It should be noted that the vehicle comprises the electrode sheet 100, and therefore comprises all the advantages of the electrode sheet 100, which will not be repeated here.

[0150] In addition, the vehicle includes but is not limited to pure electric vehicles and hybrid vehicles.

[0151] Although the embodiments of the utility model have been described in conjunction with the drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the utility model, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A pole piece, characterized in that, The electrode tab (100) comprises: a current collector (1); an active material layer (2) provided on a surface of the current collector (1), wherein the active material layer (2) is provided with an open area (201) and a first flow guide groove (202) on a surface away from the current collector (1); wherein the open area (201) is provided with a plurality of penetration holes (2011), the number of the first flow guide groove (202) is at least two, at least one of the first flow guide grooves (202) passes through the open area (201), and the two ends of the first flow guide groove (202) are respectively arranged at the opposite edges of the active material layer (2), and the penetration holes (2011) are arranged on both sides of the first flow guide groove (202) in the open area (201).

2. The pole piece of claim 1, wherein In the extension direction of the first flow guide groove (202), there is a spacing between at least one side of the open area (201) and the corresponding edge of the active material layer (2).

3. The pole piece of claim 2, wherein In the extension direction of the first flow guide groove (202), the ratio of the size of the open area (201) to the size of the active material layer (2) ranges from 15% to 80%.

4. The pole piece according to any one of claims 1 to 3, characterized in that The ratio of the depth of the penetration hole (2011) to the thickness of the active material layer (2) is greater than or equal to 40%; And / or, the ratio of the depth of the first flow guide groove (202) to the thickness of the active material layer (2) is less than or equal to 50%.

5. The pole piece according to any one of claims 1-3, characterized in that The electrode tab (100) further comprises a tab (3); wherein, in the extension direction of the first flow guide groove (202), the tab (3) is arranged at the edge of one side of the current collector (1), or, in the direction intersecting the extension direction of the first flow guide groove (202), the tab (3) is arranged at the edge of one side of the current collector (1).

6. The pole piece of any one of claims 1-3, wherein, The active material layer (2) is provided with a second flow guide groove (203) on a surface away from the current collector (1), the second flow guide groove (203) intersects the first flow guide groove (202), and at least one side of the second flow guide groove (203) is provided with the penetration hole (2011).

7. The pole piece of any of claims 1-3, wherein, The percentage of the active material lost by the active material layer (2) due to the penetration hole (2011) and the first flow guide groove (202) ranges from 0 to 5%; And / or, the diameter of the penetration hole (2011) ranges from 20 μm to 1000 μm; And / or, the spacing between adjacent penetration holes (2011) ranges from 0.1 mm to 4 mm; And / or, the width of the first flow guide groove (202) ranges from 10 μm to 200 μm; And / or, the spacing between adjacent first flow guide grooves (202) ranges from 0.1 mm to 10 mm.

8. A core, characterized by The battery comprises a positive electrode tab, a negative electrode tab and a separator; wherein the separator is arranged between the positive electrode tab and the negative electrode tab, and the negative electrode tab is arranged as the electrode tab of any one of claims 1-7.

9. A battery, characterized by The battery comprises the electrode tab of any one of claims 1-7 or the electrode core of claim 8.

10. A vehicle characterized by comprising: The battery comprises the electrode tab of any one of claims 1-7, the electrode core of claim 8 or the battery of claim 9.

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