Electrode assembly and battery

Abstract

The utility model discloses an electrode assembly which comprises a first positive plate, a first diaphragm and a first negative plate, a positive tab is arranged on the first positive plate, the first diaphragm is arranged between the first positive plate and the first negative plate, and a first through groove corresponding to the positive tab in position is formed in the first negative plate. According to the electrode assembly disclosed by the utility model, the through groove is formed in the negative electrode assembly, so that the positive electrode lug position corresponding to the negative electrode has no active substance, and when the rubberizing deviation of the positive electrode lug protection glue is relatively large, the through groove in the negative electrode assembly can effectively prevent the exposed positive electrode current collector of the positive electrode lug groove from being in contact with the negative electrode active substance at the corresponding position; the short-circuit risk is increased. In addition, the utility model also provides a battery.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of lithium ion battery especially relates to an electrode assembly and battery. BACKGROUND

[0002] With the more and more extensive use of lithium ion battery, the requirement of the fast charging capacity of lithium ion battery is also higher and higher. At present, the fast charging performance research of lithium ion battery has become the research hotspot in the field of battery. The fast charging performance of lithium ion battery depends on the structure of raw material of battery and the structure of battery, and the structure setting of battery mainly reflects the structure design of positive and negative pole piece. For example, in the aspect of battery structure, the effective means to improve the fast charging performance of lithium battery is to use the middle pole lug structure, and the positive and negative pole lug is arranged at the middle part of the pole piece. Compared with the traditional pole piece structure, the structure shortens the moving distance of electron, reduces the internal resistance of battery, and effectively improves the large rate charge and discharge capacity of battery. At present, the industry mainly pastes protective glue on the corresponding position of the negative pole piece to achieve the insulation effect, but due to the equipment error and the inspection ability level, the paste glue may be missed, resulting in the direct contact of positive and negative poles and short circuit.

[0003] The short circuit of lithium ion battery usually includes the contact short circuit of positive active layer and copper foil, the contact short circuit of positive active layer and negative active layer, the contact short circuit of negative active layer and aluminum foil, and the contact short circuit of copper foil and aluminum foil. Among them, the frequency of the contact short circuit of aluminum foil and negative active layer is the highest, and it is also the most dangerous, and there is a risk of missing protective glue in the process, which increases the risk of internal short circuit of battery. SUMMARY

[0004] The utility model discloses a kind of electrode assemblies and batteries to solve the above technical problems.

[0005] To achieve the above object, the utility model adopts the following technical scheme:

[0006] First, the utility model provides a kind of electrode assembly, including first positive pole piece, first diaphragm and first negative pole piece, the first positive pole piece is equipped with positive pole lug, the first diaphragm is located between the first positive pole piece and the first negative pole piece, first through slot corresponding with the position of the positive pole lug is opened in the first negative pole piece.

[0007] Further, the first positive pole piece is opened with first lug slot, and the positive pole lug is arranged in the first lug slot.

[0008] Further, the opposite sides of the first through slot are respectively provided with second insulating member and third insulating member.

[0009] Further, the opposite sides of the first lug slot are respectively provided with fourth insulating member and fifth insulating member.

[0010] Further, the electrode assembly further comprises a second negative plate and a second separator, the second negative plate is arranged on the first positive plate away from the first negative plate, and the second separator is arranged between the second negative plate and the first positive plate, and a second through slot corresponding to the position of the positive tab is arranged on the second negative plate.

[0011] Further, the second through slot is provided with a sixth insulating piece and a seventh insulating piece on opposite sides.

[0012] Further, the electrode assembly further comprises a second positive plate and a third separator, the second positive plate is arranged on the first negative plate away from the first positive plate, a first insulating piece corresponding to the position of the first through slot is arranged on the second positive plate, and the third separator is arranged between the second positive plate and the first negative plate.

[0013] Further, the electrode assembly further comprises a third positive plate and a fourth separator, the third positive plate is arranged on the second negative plate away from the first positive plate, an eighth insulating piece corresponding to the position of the second through slot is arranged on the third positive plate, and the fourth separator is arranged between the third positive plate and the second negative plate.

[0014] Further, the fourth insulating piece is provided with a first blocking piece, the fifth insulating piece is provided with a second blocking piece, and / or the first insulating piece is provided with a third blocking piece, and the eighth insulating piece is provided with a fourth blocking piece.

[0015] In a second aspect, the utility model provides a kind of battery, comprising the electrode assembly of any one of the above.

[0016] In summary, the utility model has the beneficial effects that:

[0017] The electrode assembly and the battery of the utility model, by being provided with through slot on negative electrode assembly, make positive tab position correspond to negative active material, and when positive tab protective glue paste deviation is larger, the through slot on negative electrode assembly can effectively avoid that the positive tab slot exposed positive current collector contacts corresponding position negative active material, increase short circuit risk. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 Structure schematic view of the electrode assembly (omitting separator) of an embodiment;

[0019] Figure 2 It is the schematic view of the cooperation relationship of the first negative plate and the second positive plate of an embodiment;

[0020] Figure 3 Structure schematic view of the electrode assembly (omitting separator) of another embodiment;

[0021] Figure 4 Structure diagram of electrode assembly (omitting diaphragm) of another embodiment.

[0022] ACCOMPA

[0023] Second positive tab 1, first insulating piece 101, first negative tab 2, first through slot 201, second insulating piece 202, third insulating piece 203, first positive tab 3, positive pole lug 301, fourth insulating piece 302, fifth insulating piece 303, first barrier piece 304, second barrier piece 305, second negative tab 4, second through slot 401, sixth insulating piece 402, seventh insulating piece 403, third positive tab 5, eighth insulating piece 501, third barrier piece 306, fourth barrier piece 307. DETAILED DESCRIPTION

[0024] 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 clearly and completely described below, obviously, the described embodiments are part of the embodiments of the utility model, not all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative labor are within the protection scope of the utility model.

[0025] Please refer to Figure 1 In a first aspect, the utility model provides an electrode assembly, including first positive tab 3, first diaphragm and first negative tab 2, be equipped with positive pole lug 301 on the first positive tab, the first diaphragm is located between the first positive tab and the first negative tab, the first negative tab is opened with the first through slot 201 corresponding with the position of the positive pole lug.

[0026] In an embodiment, the first positive tab is provided with a first lug slot, and the positive pole lug is arranged in the first lug slot.

[0027] In an embodiment, the first through slot is respectively provided with a second insulating piece 202 and a third insulating piece 203 on opposite sides.

[0028] In an embodiment, the first lug slot is respectively provided with a fourth insulating piece 302 and a fifth insulating piece 303 on opposite sides.

[0029] In an embodiment, the electrode assembly further includes a second negative tab 4 and a second diaphragm, the second negative tab is arranged on the side of the first positive tab away from the first negative tab, the second diaphragm is arranged between the second negative tab and the first positive tab, and the second negative tab is opened with the second through slot 401 corresponding with the position of the positive pole lug.

[0030] In one embodiment, opposite sides of the second through slot are respectively provided with a sixth insulating piece 402 and a seventh insulating piece 403.

[0031] In one embodiment, the electrode assembly further comprises a second positive plate 1 and a third separator, the second positive plate is arranged on the first negative plate away from the first positive plate, the second positive plate is provided with a first insulating piece 101 corresponding to the position of the first through slot, and the third separator is arranged between the second positive plate and the first negative plate.

[0032] In one embodiment, the electrode assembly further comprises a third positive plate 5 and a fourth separator, the third positive plate is arranged on the second negative plate away from the first positive plate, the third positive plate is provided with an eighth insulating piece 501 corresponding to the position of the second through slot, and the fourth separator is arranged between the third positive plate and the second negative plate.

[0033] The first insulating piece, the fourth insulating piece, the fifth insulating piece and the eighth insulating piece can prevent the burr formed by the edge of the through slot from piercing the separator and causing the positive and negative electrodes to contact and form a short circuit after the negative electrode is cut out.

[0034] The shapes of the first through slot and the second through slot are not limited, and the first through slot and the second through slot can be columnar or conical, as long as the first through slot, the second through slot and the positive tab position correspond.

[0035] The electrode assembly of the utility model is formed by stacking the second positive plate 1, the third separator, the first negative plate 2, the first separator, the first positive plate 3, the second separator, the second negative plate 4, the fourth separator and the third positive plate 5. Since the plate comprises a current collector and active layers arranged on both sides of the current collector, the utility model sets the first through slot and the second through slot on the negative active material layer, the first through slot corresponds to the first surface where the positive tab is located, the second through slot corresponds to the second surface where the positive tab is located, the first through slot and the second through slot both form through slots in the thickness direction of the negative plate, the first positive plate is provided with a first tab slot, and the positive tab is arranged in the first tab slot (the first tab slot is formed by removing part of the positive active layer, and then the positive current collector is exposed). By setting the through slot on the negative plate, the position of the positive tab corresponds to the position of the through slot on the negative plate, and the through slot position has no active material. Even if the insulating piece of the positive tab position deviates greatly, the through slot can avoid the active material in the positive tab area from contacting the negative active material in the corresponding position, thereby increasing the risk of short circuit.

[0036] Please refer to Figures 2 to 4In one embodiment, the fourth insulating member 302 is provided with a first barrier member 304, and the fifth insulating member 303 is provided with a second barrier member 305.

[0037] In one embodiment, the first insulating member 101 is provided with a third barrier member 306, and the eighth insulating member 501 is provided with a fourth barrier member 307.

[0038] The first barrier member and the third barrier member are used to fill the first through slot, and the second barrier member and the fourth barrier member are used to fill the second through slot, so as to make the thickness consistency of the electrode assembly. The width of the first barrier member and the third barrier member is less than the width of the first through slot, and the thickness H of the first barrier member and the thickness h of the fourth insulating member, and the thickness H of the second barrier member and the thickness h of the fifth insulating member satisfy 1.4≤H / h≤15, wherein 10≤h≤35, preferably 15≤h≤22, 50≤H≤190, preferably 100≤H≤150.

[0039] The third barrier member and the fourth barrier member can be omitted. When the third barrier member is omitted, the first insulating member can fill the first through slot. When the fourth barrier member is omitted, the eighth insulating member can fill the second through slot. At this time, the thickness of the first insulating member and the eighth insulating member is controlled to have filling glue on both sides of the through slot, so as to better improve the thickness consistency.

[0040] The first insulating member, the second insulating member, the third insulating member, the fourth insulating member, the fifth insulating member, the sixth insulating member, the seventh insulating member, the eighth insulating member, the first barrier member, the second barrier member, the third barrier member and the fourth barrier member can be ordinary glue paper, glue, hot melt glue, or ceramic, alumina, zirconia, bumbo stone, ternary, lithium iron phosphate, calcium oxide, calcium carbonate and other insulating materials, as long as they can have an insulating effect.

[0041] In view of the fact that the negative active layer is generally more than the positive active layer, in the width direction of the pole piece, the length of the second insulating member 202, the third insulating member 203, the sixth insulating member 402 and the seventh insulating member 403 is less than the length of the first insulating member 101, the fourth insulating member 302, the fifth insulating member 303 and the eighth insulating member 501, or in the length direction of the pole piece, the width of the second insulating member 202, the third insulating member 203, the sixth insulating member 402 and the seventh insulating member 403 is greater than the width of the first insulating member 101, the fourth insulating member 302, the fifth insulating member 303 and the eighth insulating member 501.

[0042] The preparation method of the electrode assembly comprises the following steps:

[0043] S1: dosing, stirring, coating, baking according to a conventional process;

[0044] S2: cold pressing and slitting the negative electrode sheet to obtain a narrow negative electrode sheet;

[0045] S3: calibrating the positions of the first through slot and the second through slot;

[0046] S4: sending the negative electrode sheet to a rubber sticking mechanism, setting the second insulating piece 202 and the third insulating piece 203 at the position of the first through slot, and setting the sixth insulating piece 402 and the seventh insulating piece 403 at the position of the second through slot;

[0047] S5: sending the electrode sheet to a die-cutting mechanism, die-cutting the first through slot and the second through slot at the calibrated positions, to obtain the negative electrode sheet.

[0048] In a second aspect, the utility model provides a kind of battery, and the battery uses the electrode assembly as described above.

[0049] The electrode assembly and the battery of the utility model, by being provided with through slot on negative electrode assembly, make positive pole lug position correspond to negative active material, and when positive pole lug protective rubber sticking deviation is larger, the through slot on negative electrode assembly can effectively avoid that positive pole lug slot exposed positive pole current collector contacts corresponding position negative active material, increase short circuit risk.

[0050] Finally, it should be explained that the above examples are only used to illustrate the technical solutions of the utility model and not to limit the protection scope of the utility model. Although the utility model has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the utility model can be modified or replaced equivalently without departing from the essence and scope of the technical solutions of the utility model.

Claims

1. An electrode assembly, characterized by, The electrode assembly comprises a first positive plate, a first diaphragm and a first negative plate, the first positive plate is provided with a positive tab, the first diaphragm is arranged between the first positive plate and the first negative plate, and the first negative plate is provided with a first through slot corresponding to the position of the positive tab.

2. The electrode assembly of claim 1, wherein, The first positive plate is provided with a first tab slot, and the positive tab is arranged in the first tab slot.

3. The electrode assembly of claim 2, wherein, The opposite sides of the first through slot are respectively provided with a second insulating member and a third insulating member.

4. The electrode assembly of claim 3, wherein, The opposite sides of the first tab slot are respectively provided with a fourth insulating member and a fifth insulating member.

5. The electrode assembly of claim 4, wherein, The electrode assembly further comprises a second negative plate and a second diaphragm, the second negative plate is arranged on the side of the first positive plate away from the first negative plate, the second diaphragm is arranged between the second negative plate and the first positive plate, and the second negative plate is provided with a second through slot corresponding to the position of the positive tab.

6. The electrode assembly of claim 5, wherein, The opposite sides of the second through slot are respectively provided with a sixth insulating member and a seventh insulating member.

7. The electrode assembly of claim 6, wherein, The electrode assembly further comprises a second positive plate and a third diaphragm, the second positive plate is arranged on the side of the first negative plate away from the first positive plate, the second positive plate is provided with a first insulating member corresponding to the position of the first through slot, and the third diaphragm is arranged between the second positive plate and the first negative plate.

8. The electrode assembly of claim 7, wherein, The electrode assembly further comprises a third positive plate and a fourth diaphragm, the third positive plate is arranged on the side of the second negative plate away from the first positive plate, the third positive plate is provided with an eighth insulating member corresponding to the position of the second through slot, and the fourth diaphragm is arranged between the third positive plate and the second negative plate.

9. The electrode assembly of claim 8, wherein, The fourth insulating member is provided with a first barrier member, the fifth insulating member is provided with a second barrier member, and / or the first insulating member is provided with a third barrier member, and the eighth insulating member is provided with a fourth barrier member.

10. A battery, characterized by The electrode assembly comprises any one of the electrode assemblies according to claims 1-9.

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