Battery pole piece and lithium ion battery
By setting grooves on the positive electrode and coating it with a liquid-retaining coating to absorb the electrolyte, the problem of lithium deposition in high current density areas of lithium-ion batteries is solved, thus improving the safety and lifespan of the battery.
Patent Information
- Application Number
- CN202423287474.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-30
- Publication Date
- 2025-12-26
- Estimated Expiration
- 2034-12-30
AI Technical Summary
When lithium-ion batteries are charged quickly or discharged at high rates, the current density at the negative electrode slots is high, which increases the risk of lithium deposition and reduces battery safety.
A groove is provided on the side of the positive electrode near the negative electrode, and a liquid-retaining coating is applied in the groove. The coating contains liquid-retaining additives and ceramic particles to absorb and accumulate electrolyte, thereby reducing electrolyte consumption in areas with concentrated current density.
By absorbing and accumulating electrolyte, lithium plating is reduced, improving the safety performance of lithium-ion batteries and extending their service life.
Smart Images
Figure CN223728782U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to battery technology field especially relates to a battery pole piece and lithium ion battery. BACKGROUND
[0002] The lithium ion battery usually has a tab winding structure, which is usually arranged and combined in a specific order and manner to form the core part of the battery. In the stacked structure of the battery cell, the positive plate, the negative plate and the diaphragm are stacked together in a certain order, and then the stacked structure is rolled by a rolling process, and finally the tab winding structure is formed by winding the rolling machine.
[0003] The negative tab is provided with a slot on the negative plate, and the negative tab is in good electrical connection with the negative plate through the slot. Since the slot is usually an area with high current density. When fast charging or high-rate discharging, the current density at this area will further increase. High current density will cause the speed of lithium ions to gain electrons on the negative electrode surface to increase, thereby increasing the risk of lithium precipitation, causing lithium precipitation phenomenon, and reducing the safety of lithium ion batteries.
[0004] Therefore, it is urgent to design a battery pole piece and lithium ion battery to solve the above technical problems. UTILITY MODEL CONTENT
[0005] The first purpose of the utility model is to provide a battery pole piece to reduce the phenomenon of lithium precipitation, improve the safety of lithium ion batteries, and prolong the service life.
[0006] To achieve this purpose, the utility model adopts the following technical solutions:
[0007] The utility model provides a battery pole piece, which comprises:
[0008] A negative plate is provided with a slot, and a negative tab is arranged in the slot;
[0009] A positive plate is arranged in layers with the negative plate, and both sides of the positive plate are coated with a positive active layer, wherein a recess is arranged on the positive active layer close to the negative plate, the recess is opposite to the slot, a liquid retention coating is coated in the recess, and the liquid retention coating is configured to absorb and accumulate electrolyte.
[0010] As an optional technical solution of the battery pole piece, the liquid retention coating comprises a liquid retention additive layer and ceramic particles, and the ceramic particles are arranged in the liquid retention additive layer.
[0011] As an optional technical solution of the battery pole piece, the material of the liquid retention additive layer is polypropylene or polyvinylidene fluoride.
[0012] As an optional technical solution of the battery pole piece, the material of the ceramic particles is one of bormite, silicon dioxide, magnesium hydroxide, aluminum oxide, zirconium oxide, magnesium oxide, mullite and cordierite.
[0013] As an optional technical solution of the battery pole piece, the depth of the groove is less than the thickness of the positive active layer on the side of the positive pole piece close to the negative pole piece.
[0014] As an optional technical solution of the battery pole piece, the thickness of the positive active layer on the side of the positive pole piece close to the negative pole piece is D1, and the thickness of the liquid retention coating is set as D2, 0.25xD1≤D2≤0.5xD1.
[0015] As an optional technical solution of the battery pole piece, the width of the slot is set as W1, and the width of the liquid retention coating is set as W2; W1+10mm≤W2≤W1+20mm.
[0016] As an optional technical solution of the battery pole piece, the length of the slot is set as L1, and the length of the liquid retention coating is set as L2; L1+5mm≤L2≤L1+10mm.
[0017] As an optional technical solution of the battery pole piece, the two sides of the negative pole piece are coated with negative active layers, and the negative active layers avoid the slot.
[0018] The second purpose of the utility model provides a kind of lithium ion battery, which has high safety performance, can reduce the phenomenon of lithium precipitation, and prolongs service life.
[0019] To achieve this purpose, the utility model adopts the following technical solutions:
[0020] The utility model provides a kind of lithium ion battery, the lithium ion battery includes positive pole piece, negative pole piece and diaphragm being arranged between the positive pole piece and the negative pole piece, and the positive pole piece and the negative pole piece are the battery pole piece described in any optional technical solution above.
[0021] The utility model has at least the following beneficial effects:
[0022] The utility model provides a kind of battery pole piece, which includes negative pole piece and positive pole piece, and the negative pole piece is provided with slot, and the slot is provided with negative tab.The positive pole piece and the negative pole piece are laminated, and the two sides of the positive pole piece are coated with positive active layer, wherein the positive active layer on the side close to the negative pole piece is provided with groove, the groove is opposite to the slot, the groove is coated with liquid retention coating, and the liquid retention coating is configured to absorb and accumulate electrolyte.
[0023] The utility model discloses a lithium ion battery, this lithium ion battery has higher safety performance, can reduce the phenomenon of lithium precipitation, prolong the life.
[0024] The utility model provides a kind of lithium ion battery, this lithium ion battery has higher safety performance, can reduce the phenomenon of lithium precipitation, prolong the life. BRIEF DESCRIPTION OF DRAWINGS
[0025] In order to more clearly illustrate the technical scheme in the utility model embodiment, the following will be needed to use the drawing in the utility model embodiment description briefly introduced, obviously, the following description in the drawing is only some embodiments of the utility model, for the person skilled in the art, without creative labor, according to the content of the utility model embodiment and these drawings, other drawings can be obtained.
[0026] Figure 1 It is the structural schematic diagram of battery pole piece provided by the utility model embodiment.
[0027] REFERENCE NUMERALS
[0028] 100, negative pole piece;110, slot;120, negative tab;130, negative active layer;
[0029] 200, positive pole piece;210, liquid storage coating;220, positive active layer;
[0030] 300, diaphragm. DETAILED DESCRIPTION
[0031] In order to make the purpose, technical scheme and advantage of the utility model embodiment more clearly, the following will be combined with the drawing in the utility model embodiment, the technical scheme in the utility model embodiment is clearly and completely described, obviously, the described embodiment is the part of the utility model, instead of all the embodiments.Usually the components of the utility model embodiment described and shown in the drawing here can be arranged and designed in various different configurations.
[0032] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.
[0033] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.
[0034] In the description of this utility model, it should be noted that the terms "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this utility model is in use. They are used only for the convenience of describing this utility model and for 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. Therefore, they should not be construed as limitations on this utility model. Furthermore, the terms "first," "second," and "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.
[0035] In the description of this utility model, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set" and "connection" 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. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.
[0036] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.
[0037] 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.
[0038] This embodiment provides a battery electrode that reduces lithium plating, improves the safety of lithium-ion batteries, and extends their service life.
[0039] like Figure 1 As shown, the battery electrode mainly includes a negative electrode 100 and a positive electrode 200. The negative electrode 100 has a groove 110, and a negative electrode tab 120 is disposed in the groove 110. The positive electrode 200 and the negative electrode 100 are stacked. Both sides of the positive electrode 200 are coated with a positive active layer 220. The positive active layer 220 near the negative electrode 100 has a groove, which is directly opposite the groove 110. The groove is coated with a liquid-retaining coating 210, which is configured to absorb and accumulate electrolyte.
[0040] Based on the above design, in this embodiment, the positive electrode active layer 220 near the negative electrode 100 is thinned to form a groove, which is set opposite to the slot 110 on the negative electrode 100. By coating the groove with a liquid-retaining coating 210, the liquid-retaining coating 210 can absorb and accumulate electrolyte, thereby increasing the liquid retention in the thinned area (groove area), reducing or avoiding the phenomenon of lithium plating due to high current density at the negative electrode tab 120 position during fast charging or high-rate discharge, improving the safety performance of the lithium-ion battery and extending its service life.
[0041] like Figure 1 As shown, in this embodiment, both sides of the negative electrode sheet 100 are coated with a negative electrode active layer 130. The negative electrode active layer 130 avoids the groove 110, thereby ensuring the conductivity between the negative electrode tab 120 and the negative electrode sheet 100, and also preventing the risk of internal short circuit in the lithium-ion battery.
[0042] In the embodiment, the groove area of the positive plate 200 opposite to the slot 110 of the negative plate 100 is thinned and coated with the liquid-retaining coating 210, so that the capacity of the positive active layer 220 of the groove area of the positive plate 200 is reduced, that is, the capacity of the negative active layer 130 of the slot 110 area of the negative plate 100 for setting the negative tab 120 is increased relative to the capacity of the positive active layer 220 of the groove area of the positive plate 200. At this time, the N / P value of the groove area is increased, which helps to ensure that the negative plate 100 has sufficient capacity to accept the lithium ions released by the positive plate 200 during charging, so that the negative plate 100 has more lithium intercalation sites, improves the lithium precipitation window of the negative plate 100, and reduces the phenomenon of lithium deposition (i.e. lithium precipitation) of the negative plate 100 during charging, thereby improving the safety and cycle life of the lithium ion battery.
[0043] Optionally, the liquid-retaining coating 210 in the embodiment includes a liquid-retaining additive layer and ceramic particles, and the ceramic particles are arranged in the liquid-retaining additive layer. Illustratively, the liquid-retaining additive layer is made of a liquid-retaining additive, and the ceramic particles can be arranged as ceramic microsphere powder. The operator can flexibly adjust the ratio of the liquid-retaining additive and the ceramic microsphere powder according to actual needs, which is not limited in the embodiment.
[0044] Specifically, the material of the liquid-retaining additive layer in the embodiment is polypropylene or polyvinylidene fluoride. Illustratively, the liquid-retaining additive layer can be arranged as at least one of a blend powder of butyronitrile and polyvinyl chloride, polypropylene micro powder, ultra-high molecular weight polyethylene powder, and linear crystalline polyvinylidene fluoride polymer.
[0045] The material of the ceramic particles is one of bormite, silicon dioxide, magnesium hydroxide, aluminum oxide, zirconium oxide, magnesium oxide, mullite, and cordierite. Illustratively, the ceramic particles can be arranged as at least one of bormite, silicon dioxide, magnesium hydroxide, aluminum oxide, zirconium oxide, magnesium oxide, mullite, and cordierite in the form of spherical powder.
[0046] It should be noted that the liquid-retaining additive layer and the ceramic particles in the embodiment are existing materials, and the operator can flexibly adjust the components of the liquid-retaining additive layer and the components of the ceramic particles according to actual needs. Therefore, the principle of the liquid-retaining coating 210 absorbing and accumulating electrolyte is not described in detail in the embodiment.
[0047] In the embodiment, the depth of the groove is less than the thickness of the positive active layer 220 of the positive plate 200 close to the negative plate 100, so that the positive active layer 220 with a certain thickness between the groove and the positive plate 200 can be ensured, thereby reducing or avoiding the short circuit phenomenon caused by the direct contact between the negative tab 120 and the positive plate 200, improving the safety of the lithium ion battery, and also ensuring the integrity of the positive plate 200 and avoiding damage to the positive plate 200.
[0048] Optionally, the thickness of the positive electrode active layer 220 on the side of the positive electrode 200 closest to the negative electrode 100 is D1, such as... Figure 1 As shown, the thickness D1 of the positive electrode active layer 220 refers to the thickness of the positive electrode active layer 220 in the non-groove area. Simultaneously, the thickness of the positive electrode active layer 220 on both sides of the positive electrode sheet 200 is the same, improving processing efficiency. The thickness of the liquid-retaining coating 210 is set to D2, where 0.25×D1≤D2≤0.5×D1. This not only minimizes lithium plating on the battery electrode sheet but also saves on the material consumption of the liquid-retaining coating 210, facilitating subsequent rolling processes. When the thickness of the liquid-retaining coating 210 is too thin, for example, D2<0.25×D1, the liquid-retaining capacity is limited, and lithium plating at the negative electrode tab 120 position remains relatively severe. When the thickness of the liquid-retaining coating 210 is too thick, for example, D2>0.5×D1, this not only increases the material consumption of the liquid-retaining coating 210, increasing costs, but may also cause unevenness on the battery electrode sheet, affecting subsequent rolling processes.
[0049] Optionally, such as Figure 1 As shown, in this embodiment, the width of the groove 110 is set to W1, and the width of the liquid-retaining coating 210 is set to W2; W1+10mm≤W2≤W1+20mm. The length of the groove 110 is set to L1 (not shown in the figure), and the length of the liquid-retaining coating 210 is set to L2; L1+5mm≤L2≤L1+10mm. It can be understood that the width direction of the liquid-retaining coating 210 is... Figure 1 The X-axis direction in the figure represents the thickness direction of the liquid-retaining coating 210. Figure 1 In the Y-axis direction, the length direction of the liquid-retaining coating 210 (not shown in the figure) is perpendicular to both the X-axis and Y-axis directions.
[0050] This not only allows the liquid-retaining coating 210 to be placed inside the groove, but also ensures that a certain amount of liquid-retaining coating 210 is coated in the surrounding area of the groove, thereby further reducing the phenomenon of lithium plating on the battery electrode, improving the safety of the lithium battery, and extending its service life.
[0051] This embodiment also provides a lithium-ion battery, which includes a positive electrode 200, a negative electrode 100, and a separator 300 disposed between the positive electrode 200 and the negative electrode 100, wherein the positive electrode 200 and the negative electrode 100 are the battery electrodes described above.
[0052] The diaphragm 300 can isolate the positive electrode sheet 200 and the negative electrode sheet 100, thereby avoiding the risk of short circuit caused by the direct contact of the positive electrode sheet 200 and the negative electrode sheet 100. Although the diaphragm 300 isolates the positive electrode sheet 200 and the negative electrode sheet 100, the diaphragm 300 has excellent ion conduction performance, allowing lithium ions to be freely transmitted between the positive electrode sheet 200 and the negative electrode sheet 100, thereby ensuring that the lithium ion battery can normally carry out charge and discharge reactions.
[0053] The positive electrode sheet 200, the negative electrode sheet 100 and the diaphragm 300 in the embodiment can be provided in multiple layers, and one layer of the diaphragm 300 is arranged between each layer of the positive electrode sheet 200 and each layer of the negative electrode sheet 100.
[0054] The lithium ion battery has high safety performance, can reduce the phenomenon of lithium precipitation, and prolongs the service life.
[0055] Obviously, the above only describes preferred embodiments of the present application and the technical principles applied. Those skilled in the art will understand that the present application is not limited to the specific embodiments herein, and various obvious changes, re-adjustments and substitutions can be made by those skilled in the art without departing from the scope of the present application. Therefore, although the present application has been described in detail through the above embodiments, the present application is not limited to the above embodiments, and more other equivalent embodiments can be included without departing from the concept of the present application, and the scope of the present application is determined by the scope of the appended claims.
[0056] Note that in the description of the present specification, the description referring to the terms "some embodiments", "other embodiments", and the like means that the specific features, structures, materials or characteristics described in connection with the embodiments or examples are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.
Claims
1. A battery pole piece, characterized by, The application relates to a lithium ion battery and a battery pole piece. The battery pole piece comprises a negative pole piece (100) provided with a slot (110) and a negative tab (120) arranged in the slot (110); and a positive pole piece (200) arranged in a stack with the negative pole piece (100), both sides of the positive pole piece (200) being coated with a positive active layer (220), wherein a recess is arranged on the positive active layer (220) close to the negative pole piece (100), the recess is opposite to the slot (110), and a liquid reserve coating (210) is coated in the recess, the liquid reserve coating (210) being configured to absorb and accumulate electrolyte. The liquid reserve coating (210) comprises a liquid reserve additive layer and ceramic particles arranged in the liquid reserve additive layer.
2. The battery pole piece of claim 1, wherein, The material of the liquid reserve additive layer is polypropylene or polyvinylidene fluoride.
3. The battery pole piece of claim 2, wherein, The material of the ceramic particles is one of bormite, silicon dioxide, magnesium hydroxide, aluminum oxide, zirconium oxide, magnesium oxide, mullite and cordierite.
4. The battery pole piece of claim 2, wherein, The depth of the recess is less than the thickness of the positive active layer (220) of the positive pole piece (200) close to the negative pole piece (100).
5. The battery pole piece of claim 1, wherein, The thickness of the positive active layer (220) of the positive pole piece (200) close to the negative pole piece (100) is D1, the thickness of the liquid reserve coating (210) is D2, and 0.25xD1<=D2<=0.5xD1.
6. The battery pole piece of any one of claims 1-5, wherein, The width of the slot (110) is W1, and the width of the liquid reserve coating (210) is W2; W1+10mm<=W2<=W1+20mm.
7. The battery pole piece of any one of claims 1-5, wherein, The length of the slot (110) is L1, and the length of the liquid reserve coating (210) is L2; L1+5mm<=L2<=L1+10mm.
8. The battery pole piece of any one of claims 1-5, wherein, Both sides of the negative pole piece (100) are coated with a negative active layer (130), and the negative active layer (130) avoids the slot (110).
9. The battery pole piece of any one of claims 1-5, wherein, The lithium ion battery comprises a positive pole piece (200), a negative pole piece (100) and a separator (300) arranged between the positive pole piece (200) and the negative pole piece (100), the positive pole piece (200) and the negative pole piece (100) being the battery pole piece according to any one of claims 1-9.
10. A lithium-ion battery, characterized by,