CN212695222U

CN212695222U - Lithium ion battery radiating through pole piece

Info

Publication number: CN212695222U
Application number: CN202021837914.0U
Authority: CN
Inventors: 尚德华; 杨泽乾
Original assignee: Aopu Shanghai New Energy Co Ltd
Current assignee: Aopu Shanghai New Energy Co Ltd
Priority date: 2020-08-28
Filing date: 2020-08-28
Publication date: 2021-03-12
Anticipated expiration: 2030-08-28

Abstract

The utility model relates to a lithium ion battery which dissipates heat through pole pieces. The utility model includes an electric core, the electric core includes a plurality of positive electrode sheets and a plurality of negative electrode sheets, and is wound or stacked in the order of the negative electrode sheet, the separator, the positive electrode sheet, the separator and the negative electrode sheet, and one end of the positive electrode sheet is provided with a positive electrode Conductive electrode lugs and positive electrode heat-conducting electrode lugs, a plurality of positive electrode conductive electrode lugs and a plurality of positive electrode heat-conducting electrode lugs are respectively aligned and welded together, and a positive electrode conductive electrode post and a positive electrode heat-conducting electrode post are welded together, and one end of the negative electrode sheet is provided with a negative electrode conductive electrode lug and negative heat conducting tabs, a plurality of negative electrode conducting tabs and a plurality of negative heat conducting tabs are respectively aligned and welded together, and are welded with a negative electrode conducting electrode post and a negative electrode heat conducting electrode post, the positive electrode conducting electrode post, the positive electrode heat conducting The conductive electrode post and the negative conductive electrode post are both fixed on a cover plate, and the cover plate is adapted to the battery core. The utility model adopts the method of increasing the heat-conducting tabs, which has no influence on the process and design of the lithium ion battery, and achieves the effect of good heat dissipation performance.

Description

Lithium ion battery radiating through pole piece

Technical Field

The utility model relates to a lithium ion battery technical field, specific lithium ion battery through pole piece heat dissipation that says so.

Background

Because the lithium ion battery has the advantages of high energy density, long service life, environmental protection and the like, the lithium ion battery is widely applied to the fields of energy storage, electric tools and automobiles. With the technological progress and the pressure to reduce costs, lithium ion batteries are developing toward large-scale and high energy density, which puts higher demands on heat dissipation and thermal management of the batteries.

At present, in the field of lithium ion batteries, because the service life of the lithium ion batteries can be shortened sharply at high temperature, and even safety risks are caused, the lithium ion batteries need a targeted heat dissipation design when being applied, and particularly, when the lithium ion batteries are applied at a large multiplying power for a long time, a large amount of heat can be generated, the heat generated by the batteries is often different, the heat generated by the batteries needs to be diffused out in time, otherwise, the service life of the batteries is reduced rapidly, and even explosion or combustion is caused. The temperature of the battery is kept consistent, otherwise, the consistency of the battery is greatly different after a period of operation, and the service life of the battery pack is reduced due to the short plate effect.

The current technical scheme is generally to carry out heat dissipation design on the whole when lithium ion batteries are grouped to form a battery pack, and adopts air cooling (also called air cooling) and liquid cooling (mainly water cooling) methods. Air cooling takes away the heat in the battery package through air flow promptly, and although the cost is lower than the liquid cooling, the wind channel design is complicated, causes battery temperature distribution inhomogeneous easily, and the battery uniformity worsens fast. Liquid cooling is realized by arranging liquid cooling pipelines in the battery pack, the pipelines are filled with water or cooling liquid, and heat in the battery pack is taken away by flowing of the cooling water, but the battery pack is complex in structure and high in cost. The heat dissipation design for the lithium ion battery is mainly pole piece heat dissipation and pole column heat conduction. In the heat dissipation of the pole piece, a material with good heat conductivity is added during the preparation of slurry or a heat-conducting coating is added on the surface of the pole piece to improve the heat dissipation performance of the pole piece, so that the process complexity and the production cost are increased, and the capacity of a battery is reduced; the heat conduction of the pole is realized by adding a medium with good heat conductivity at the pole or connecting the medium with the pole to increase the heat dissipation performance, and the pole is also a heating body, so the heat dissipation effect on the battery is limited.

The air cooling mode and the liquid cooling mode are both realized by contacting a cooling medium with the shell of the battery and conducting and taking away heat through the flowing of the cooling medium. Therefore, the first premise of good heat dissipation effect is that the heat inside the battery can be transferred to the battery shell, and the heat generated by the pole piece inside the battery is transferred to the shell through the electrolyte and the conductive pole column. The electrolyte amount in the electric core is few to can reduce along with the length of time of using, and the outside of electric core often has an insulation protection layer still, and these are all unfavorable for the heat conduction of electric core pole piece, therefore the electric core pole piece heat transfer to shell process is slow and inefficiency. The conductive electrode pillar has a high temperature due to the passing of current, so the heat dissipation effect is limited. By adding the heat conducting agent into the battery pole piece, the heat conducting effect is limited, the process difficulty is increased, and other performances of the battery are reduced.

SUMMERY OF THE UTILITY MODEL

To the above-mentioned weak point that exists among the prior art, the to-be-solved technical problem of the utility model is to provide a through radiating lithium ion battery of pole piece.

The utility model discloses a realize that the technical scheme that above-mentioned purpose adopted is: a lithium ion battery radiating heat through pole pieces comprises a battery cell, wherein the battery cell comprises a plurality of positive pole pieces and a plurality of negative pole pieces, and winding or laminating the negative plate, the diaphragm, the positive plate, the diaphragm and the negative plate in sequence, it is characterized in that one end of the positive plate is provided with a positive conductive tab and a positive conductive tab, a plurality of positive conductive tabs and a plurality of positive conductive tabs are respectively aligned and welded together and welded with a positive conductive pole column and a positive conductive pole column, one end of the negative plate is provided with a negative electrode conductive tab and a negative electrode heat conduction tab, a plurality of negative electrode conductive tabs and a plurality of negative electrode heat conduction tabs are respectively aligned and welded together and welded with a negative electrode conductive electrode column and a negative electrode heat conduction electrode column, the positive electrode conductive pole, the negative electrode conductive pole and the negative electrode conductive pole are all fixed on the cover plate, and the cover plate is matched with the battery core.

The positive conductive tab and the positive heat conductive tab are positioned at one end of the positive plate in the width direction; and the negative electrode conductive lug and the negative electrode heat-conducting lug are positioned at one end of the negative plate in the width direction.

The negative heat conducting tab is positioned in the middle between the negative heat conducting tab and the central point of the upper edge of the negative plate; the positive heat conducting tab is located in the middle between the positive heat conducting tab and the central point of the upper edge of the positive plate.

And an explosion-proof valve is arranged in the middle of the cover plate.

The positive heat-conducting pole column is located between the positive heat-conducting pole column and the explosion-proof valve, the negative heat-conducting pole column is located between the negative heat-conducting pole column and the explosion-proof valve, and the positive heat-conducting pole column and the negative heat-conducting pole column are located on two sides of the explosion-proof valve.

The positive pole, the negative pole and the cover plate are separated by ceramic, and the protruding cover plate part of the positive pole and the negative pole is coated with a compact heat-conducting insulating layer and completely covers the positive pole and the negative pole.

The compact heat conduction insulating layer is 0.5mm-5 mm.

And a stopping frame is fixed outside the battery cell and the cover plate.

And heat-conducting insulating sheets are sleeved outside the positive heat-conducting pole and the negative heat-conducting pole.

The utility model has the advantages of it is following and beneficial effect: the utility model discloses an increase the method of heat conduction utmost point ear, do not have the influence to lithium ion battery's technology and design, only keep a pair of utmost point ear more when cutting, make simply. Through heat conduction utmost point ear and heat conduction utmost point post connection, because heat conduction utmost point ear and heat conduction utmost point post do not have the electric current to pass through itself, so it does not produce the heat, and the temperature is low, and the heat of the electric core pole piece of each piece can all transmit the outside heat dissipation of battery through utmost point ear, heat conduction utmost point post, can not cause inside heat accumulation, and the temperature of each battery pole piece is more even, has improved heat dispersion and uniformity. Through heat conduction utmost point post and shell or external cooling medium connection, heat transfer efficiency is higher, therefore heat dispersion is better.

Drawings

FIG. 1 is an exploded view of the present invention;

FIG. 2 is an overall structure diagram of the present invention;

FIG. 3 is a structural diagram of the positive plate of the present invention;

fig. 4 is a structure diagram of the negative electrode sheet of the present invention.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and examples.

As shown in fig. 1-4, a lithium ion battery dissipating heat through a pole piece comprises an electric core, the electric core comprises a plurality of positive plates 21 and a plurality of negative plates 22, and is wound or laminated according to the order of the negative plates 22, a diaphragm, the positive plates 21, the diaphragm, and the negative plates 22, one end of the positive plates 21 is provided with a positive conductive tab 41 and a positive conductive tab 31, the positive conductive tabs 41 and the positive conductive tabs 31 are respectively aligned and welded together and welded with a positive conductive post and a positive conductive post, one end of the negative plates 22 is provided with a negative conductive tab 42 and a negative conductive tab 32, the negative conductive tabs 42 and the negative conductive tabs 32 are respectively aligned and welded together and welded with a negative conductive post and a negative conductive post, the positive conductive post, the negative conductive post, and the negative conductive post are all fixed on a cover plate 6, the cover plate 6 is matched with the battery core. The positive conductive tab 41 and the positive conductive tab 31 are positioned at one end of the positive plate 21 in the width direction; the negative electrode conductive tab 42 and the negative electrode thermal conductive tab 32 are located at one end of the negative electrode sheet 22 in the width direction. The heat conducting tabs 3 include a positive heat conducting tab 31 and a negative heat conducting tab 32. The conductive tabs 4 include a positive conductive tab 41 and a negative conductive tab 42. The conductive electrode column 7 comprises a positive conductive electrode column and a negative conductive electrode column. The heat conduction pole comprises a positive heat conduction pole and a negative heat conduction pole.

The middle part of the cover plate 6 is provided with an explosion-proof valve 10. The positive electrode heat-conducting pole 31 is located between the positive electrode heat-conducting pole 41 and the explosion-proof valve 10, the negative electrode heat-conducting pole 32 is located between the negative electrode heat-conducting pole 42 and the explosion-proof valve 10, and the positive electrode heat-conducting pole 31 and the negative electrode heat-conducting pole 32 are located on two sides of the explosion-proof valve 10.

Separate through pottery between anodal heat conduction utmost point post 31, the negative pole heat conduction utmost point post 32 and the apron 6, the partial coating of anodal heat conduction utmost point post, negative pole heat conduction utmost point post protrusion apron 6 has fine and close heat conduction insulating layer and will anodal heat conduction utmost point post 31 and negative pole heat conduction utmost point post 32 cover completely. The compact heat conduction insulating layer is 0.5mm-5 mm.

And a stopping frame 5 is fixed outside the battery core and the cover plate 6. And the heat-conducting insulating sheets 9 are sleeved outside the positive heat-conducting pole 31 and the negative heat-conducting pole 32.

The manufacturing method of the utility model comprises the following steps:

1) firstly, manufacturing a negative plate and a positive plate, wherein along the width direction of the negative plate or the positive plate, coating areas are positioned at two sides, and a blank area is positioned in the middle;

2) designing the tabs of the negative plate and the positive plate: firstly, designing lugs of a negative plate and a positive plate as conductive lugs according to a normal process, designing a negative heat-conducting lug at the middle position between the negative plate lug and a battery cell, and designing a positive heat-conducting lug at the middle position between the positive plate lug and the battery cell;

3) finishing the cutting of the corresponding positive and negative pole pieces according to the design of the step 2;

4) assembling a bare cell by adopting a winding or lamination assembly mode according to the sequence of the negative plate, the diaphragm, the positive plate, the diaphragm and the negative plate;

5) respectively aligning and welding the conductive tab and the heat-conducting tab of the bare cell together, and then respectively welding the conductive tab and the heat-conducting tab on the conductive pole column and the heat-conducting pole column of the specially-made cover plate;

6) cover plate: the cover plate is provided with a positive heat conduction pole terminal and a negative heat conduction pole terminal besides a normal positive pole terminal and a normal negative pole terminal, and the heat conduction pole terminals are respectively positioned between the explosion-proof valve and the positive and negative heat conduction pole terminals and correspond to the lugs of the positive and negative pole pieces. The heat conducting pole is separated from the cover plate through ceramic with good heat conductivity, and the part of the heat conducting pole, which protrudes out of the cover plate, is coated with a dense heat conducting insulating material with the thickness of 0.5-5 mm to form a heat conducting insulating sheet 9 in the figure 1, so that the terminal of the heat conducting pole is completely covered, and the heat conducting pole only conducts heat and is insulated from the outside and the cover plate;

7) installing an insulating bag and a stopping frame, placing the naked electric core into the shell, and hermetically welding the cover plate and the shell;

8) injecting the battery core with qualified moisture into the required electrolyte;

9) and after liquid injection, the battery core is subjected to aging, formation, sealing, capacity grading, detection and other steps to prepare the battery.

10) When the lithium ion battery works, the place where current passes can generate heat, and because the current at the conducting electrode column is large, a large amount of heat can be generated, the temperature of the conducting electrode column is not greatly different from the temperature inside the battery, and is even higher, so that the heat dissipation effect through the conducting electrode column is very limited. And battery core and battery casing have taken insulation protection, therefore the heat of electricity core need slowly conduct to the casing through electrolyte and insulating protective sheath and distribute away again, and the radiating efficiency is low, and especially the inside pole piece heat of battery core is difficult to the effluvium, can lead to the quick degradation of inside pole piece performance. Through the design of heat conduction utmost point post, because it does not have the electric current to pass through itself, so it does not produce the heat, and the temperature is low, is connected the back with battery pole piece utmost point ear, and the heat of the electric core pole piece of each piece all can transmit the outside heat dissipation of battery through utmost point ear, heat conduction utmost point post, can not cause inside heat accumulation, and the temperature of each battery pole piece is more even, has improved heat dispersion and uniformity.

Claims

1. A lithium ion battery dissipating heat by a pole piece, comprising a battery core, the battery core comprising a plurality of positive electrode sheets and a plurality of negative electrode sheets, and wound according to the order of negative electrode sheets, separators, positive electrode sheets, separators, and negative electrode sheets Or laminated assembly, characterized in that one end of the positive electrode sheet is provided with a positive electrode conductive electrode lug and a positive electrode conductive electrode lug, and a plurality of positive electrode conductive electrode lugs and a plurality of positive electrode conductive electrode lugs are respectively aligned and welded together and welded with a positive electrode conductive electrode lug. A pole and a positive heat-conducting pole, one end of the negative plate is provided with a negative-conducting tab and a negative-conducting tab, a plurality of negative-conducting tabs and a plurality of negative-conducting tabs are respectively aligned and welded together, and a negative-conducting electrode is welded A column and a negative thermal conductive pole, the positive conductive pole, the positive thermal conductive pole, the negative conductive pole and the negative thermal conductive pole are all fixed on a cover plate, and the cover plate is adapted to the battery core.

2 . The lithium ion battery according to claim 1 , wherein the positive electrode conductive tab and the positive electrode conductive tab are located at one end in the width direction of the positive electrode; the negative electrode is electrically conductive. 3 . The tabs and the negative heat conducting tabs are located at one end of the negative electrode sheet in the width direction.

3. The lithium ion battery according to claim 1, characterized in that, the negative thermal conductive tab is located in the middle position between the negative conductive tab and the upper center point of the negative tab; so The positive thermal conductive tab is located at a middle position between the positive conductive tab and the center point along the upper edge of the positive electrode sheet.

4 . The lithium-ion battery according to claim 1 , wherein an explosion-proof valve is provided in the middle of the cover plate. 5 .

5. The lithium ion battery according to claim 4, characterized in that, the positive thermal conductive pole is located between the positive thermal conductive pole and the explosion-proof valve, and the negative thermal conductive pole is located in the middle of the positive thermal conductive pole and the explosion-proof valve. The negative conductive pole and the explosion-proof valve are located between the positive and negative conductive poles, and the positive thermally conductive pole and the negative pole are located on both sides of the explosion-proof valve.

6 . The lithium ion battery according to claim 1 , wherein the positive thermally conductive pole, the negative thermally conductive pole and the cover plate are separated by ceramics, and the positive thermally conductive pole The part of the column and the negative thermal conductive pole protruding from the cover plate is coated with a dense thermal conductive insulating layer and completely covers the positive thermal conductive pole and the negative thermal conductive pole.

7 . The lithium ion battery according to claim 6 , wherein the dense thermally conductive insulating layer is 0.5mm-5mm. 8 .

8 . The lithium-ion battery according to claim 1 , wherein a stopper is fixed outside the battery cell and the cover plate. 9 .

9 . The lithium ion battery according to claim 1 , wherein the positive thermally conductive pole and the negative thermally conductive pole are covered with thermally conductive insulating sheets. 10 .