Square battery

Abstract

The utility model provides a square battery which comprises a cover plate, the cover plate comprises a pole and a pole terminal, one side, facing the interior of the battery, of the cover plate is provided with an insulating heat conduction coating, and the end face of the pole terminal protrudes out of the coating face of the insulating heat conduction coating; the current collecting piece comprises a terminal welding part and a current collecting welding part connected with the terminal welding part, the terminal welding part is connected with the pole terminal in a welding manner, a boss protruding towards the cover plate is arranged on the terminal welding part, and the boss abuts against the insulating heat conduction coating on the cover plate. According to the battery disclosed by the invention, heat in the battery can be quickly transferred to the cover plate, so that quick heat dissipation is realized.

Description

TECHNICAL FIELD

[0001] The utility model relates to battery technology field, concretely relates to a square battery. BACKGROUND

[0002] The existing cover plate adopts aluminum plate, and a PP material plastic piece with a thickness of about 1-6mm is arranged below the aluminum plate to play the role of insulating cover plate and connecting piece. During use of the battery, the cell inside the battery generates heat, part of the heat is conducted to the pole post on the cover plate through the pole lug of the cell and the PP material plastic piece, and then the heat is conducted to the aluminum shell. On the one hand, the heat transfer of this path is slow due to the insulating film arranged between the aluminum shell and the cell for insulation, and on the other hand, there is a thick PP material plastic between the pole post and the aluminum plate of the cover plate, so that the heat of the pole post can only be dissipated through the end surface. Although the pole post end surface conducts heat quickly, but due to the small volume and end surface area of the pole post, and the heat generation of the pole post itself, the heat dissipation through this path is limited, which leads to the accumulation of heat inside the cell, the temperature is too high, the temperature is not uniform, the long-term use causes the rapid attenuation of the cycle life, and even affects the safety performance. SUMMARY

[0003] In order to overcome the defects in the prior art, the utility model embodiment provides a square battery, which can quickly transfer the heat inside the battery to the cover plate and realize rapid heat dissipation.

[0004] In order to achieve the above purpose, the utility model adopts the technical scheme of:

[0005] The utility model discloses a square battery, which comprises:

[0006] The cover plate comprises a pole post and a pole post terminal, one side of the cover plate towards the inside of the battery is provided with an insulating heat conducting coating, and the end surface of the pole post terminal protrudes from the coating surface of the insulating heat conducting coating.

[0007] The current collector piece comprises a terminal welding part and a current collecting welding part connected with the terminal welding part, the terminal welding part is welded and connected with the pole post terminal, the terminal welding part is provided with a boss protruding towards the cover plate, and the boss is in abutment with the insulating heat conducting coating on the cover plate.

[0008] The technical scheme has the following beneficial effects: the insulating and heat-conducting coating is arranged on the cover plate, and the boss is arranged on the terminal welding part of the current collecting piece to be in contact with the insulating and heat-conducting coating, the terminal welding part of the current collecting piece is welded to the terminal of the pole, and the current collecting welding part is welded to the tab, in the use process of the battery, the heat in the battery cell is transferred to the current collecting welding part welded to the tab, the heat of the current collecting welding part is not only transferred to the pole terminal and the pole through the terminal welding part for heat dissipation, but also conducted to the insulating and heat-conducting coating of the cover plate through the boss, the insulating and heat-conducting coating has good insulation and heat conduction, can quickly conduct the heat to the cover plate, the cover plate has a large volume and can absorb a certain amount of heat, the cover plate has a large contact area with the outside, and can quickly dissipate heat, so that the heat in the battery can be quickly absorbed and dissipated, and the heat dissipation is realized.

[0009] Further, the terminal welding part has a first end extending in a first direction, the boss is arranged at a second end of the terminal welding part, one end of the current collecting welding part is connected to a side of the boss away from the terminal welding part, and the other end extends in a second direction away from the boss, and the first direction in which the terminal welding part extends is perpendicular or substantially perpendicular to the second direction in which the current collecting welding part extends.

[0010] The current collecting piece formed by the connection of the terminal welding part and the current collecting welding part is arranged on the battery cell, so that the current collecting piece can be welded in the battery, and the closer the current collecting welding part is to the boss, the higher the heat transfer efficiency is.

[0011] Further, the boss has an extension part extending from one side of the boss in a third direction, and the current collecting welding part is connected to the extension part of the boss.

[0012] When the current collecting welding part is connected to the boss, the extension part facilitates the welding of the current collecting welding part to the tab of the battery cell, so that the current collecting piece can reduce the cross-sectional area and weight while meeting the overcurrent capacity.

[0013] Further, the terminal welding part is provided with a welding site welded to the terminal of the pole, the welding site is arranged close to the first end of the terminal welding part, and the welding site is provided with a first through hole. The first through hole arranged on the welding site can increase the surface area of the conductor of the current collecting piece, enhance the conductivity, reduce the weight of the current collecting piece, and improve the energy density.

[0014] Further, the current collecting welding part is provided with at least one through hole. The through hole is arranged in the welding area of the current collecting welding part and the tab of the battery cell, the existence of the through hole affects the local ultrasonic welding effect, can improve the ultrasonic vibration field in the welding process, and can improve the edge cracking of the tab.

[0015] Further, the end face of the pole terminal forms a first height difference with the coated face of the insulating and heat-conducting coating, and the plane of the boss forms a second height difference with the plane of the terminal welding part, the second height difference being greater than the first height difference.

[0016] The terminal welding part is welded to the pole terminal, and due to the second height difference being greater than the first height difference, the boss of the terminal welding part can abut against the insulating and heat-conducting coating on the cover plate after welding, so that the heat inside the battery cell can be transmitted to the current collecting welding part through the tab, and then quickly conducted to the insulating and heat-conducting coating through the boss, and the insulating and heat-conducting coating can quickly conduct the heat to the cover plate.

[0017] Further, the first height difference is 0.3-0.5 mm, the second height difference is 0.4-0.6 mm, and the difference between the second height difference and the first height difference is 0.05-0.1 mm. The first height difference and the second height difference can quickly transmit the heat to the current collecting part and the insulating and heat-conducting coating, and can also avoid occupying the internal space of the battery, thereby improving the utilization rate of the internal space of the battery.

[0018] Further, the thickness of the insulating and heat-conducting coating is 0.3-1 mm. The insulating and heat-conducting coating can eliminate the need for a plastic part under the cover plate in the battery, and can not only play the role of insulation of the current collecting part and the cover plate, but also transmit the heat generated in the battery to the cover plate through the current collecting part and the insulating and heat-conducting coating, thereby increasing the heat dissipation effect, and the thickness of the coating is thinner than the original plastic part under the cover plate, thereby improving the utilization rate of the internal space of the battery.

[0019] Further, the material of the insulating and heat-conducting coating is at least polyimide. The insulating and heat-conducting coating can be made of various insulating and heat-conducting materials, and has good insulation and heat conduction performance, thereby playing the roles of insulation and heat conduction, for example, polyimide.

[0020] Further, the utility model also comprises:

[0021] A shell, the cover plate is connected with the shell, and the current collecting part is arranged in the shell.

[0022] A battery cell, the battery cell is provided with tabs at two ends, and the current collecting welding part is welded to the tabs. The current collecting welding part is connected to the tabs, so that the heat inside the battery cell can be transmitted to the current collecting welding part through the tabs.

[0023] Due to the use of the above technical solutions, the utility model has the following advantages compared with the prior art:

[0024] 1. The application sets an insulating and heat-conducting coating on the cover plate and sets a boss in conflict with the insulating and heat-conducting coating on the terminal welding part of the current collector, since the terminal welding part of the current collector is welded and connected with the pole terminal and the current collector welding part is welded and connected with the pole lug, the heat inside the battery during use is transferred to the current collector welding part through the pole lug, the heat of the current collector welding part is not only transferred to the pole terminal and the pole through the terminal welding part for heat dissipation, but also conducted to the insulating and heat-conducting coating of the cover plate body through the boss, since the insulating and heat-conducting coating has good insulation and heat conduction performance, the heat can be quickly conducted to the cover plate, the cover plate has a large volume and can absorb a certain amount of heat, the cover plate has a large contact area with the outside and can quickly dissipate heat, so that the heat inside the battery can be quickly absorbed and dissipated, and rapid heat dissipation is realized.

[0025] 2. The application sets a through hole on the welding position of the terminal welding part, so that the surface area of the current collector conductor is increased, the conductivity is enhanced, the weight of the current collector is reduced, and the internal energy density of the battery is improved.

[0026] 3. The application sets a through hole on the current collector welding part, and the through hole is arranged in the welding area of the current collector welding part and the pole lug of the battery cell, since the existence of the through hole affects the local ultrasonic welding effect, the ultrasonic vibration field in the welding process can be improved, and the edge welding crack of the pole lug can be improved.

[0027] In order to make the above and other purposes, characteristics and advantages of the utility model more obvious and easy to understand, the following preferred embodiments are described in detail below, and the accompanying drawings are described as follows. BRIEF DESCRIPTION OF DRAWINGS

[0028] In order to more clearly illustrate the technical scheme in the embodiments of the utility model or the prior art, the following will briefly introduce the drawings needed to be used in the embodiment or the prior art description, obviously, the drawings in the following description are only some embodiments of the utility model, and for those skilled in the art, other drawings can be obtained without creative labor on the premise of the drawings.

[0029] Figure 1 It is a square battery internal structure schematic view provided by the embodiment of the utility model;

[0030] Figure 2 It is a cover plate and pole lug connection schematic view provided by the embodiment of the utility model;

[0031] Figure 3 It is a current collector structure view provided by the embodiment of the utility model;

[0032] Figure 4 It is a current collector local enlarged structure view provided by the embodiment of the utility model;

[0033] Figure 5 is a square battery structure sectional view provided by the embodiment of the utility model;

[0034] Figure 6 is a square battery structure partial enlarged sectional view provided by the embodiment of the utility model.

[0035] The above figure reference signs: 1, cover plate; 2, current collector; 3, positive terminal; 4, negative terminal; 5, insulating heat-conducting coating; 6, terminal welding portion; 7, current collector welding portion; 8, boss; 9, extension; 10, welding site; 11, cell; 12, positive tab; 13, negative tab; 14, first through hole; 15, through hole; 16, shell. DETAILED DESCRIPTION

[0036] The technical solutions in the embodiments of the utility model will be clearly and completely described below with reference to the drawings in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all the embodiments. In addition, the drawings of the utility model are only simple schematic illustrations, not the depiction of actual dimensions, and the prior declaration is made.

[0037] In the utility model, it needs to be explained that the directions or position relations indicated by the terms "upper", "lower", "inner", "outer", "forward", "backward", "between", "close to", "far away" and the like are the directions or position relations based on the directions or position relations shown in the drawings, and are only for the convenience of describing the utility model and simplifying the description, and are not indicative or suggestive of the devices or elements indicated having to have a specific direction, to be constructed and operated in a specific direction, and therefore cannot be understood as limiting the utility model. It also needs to be explained that, unless explicitly specified and limited, the terms "mounting", "connecting" should be understood broadly, for example, can be fixedly connected, or can be detachably connected, or integrally connected; can be directly connected, or indirectly connected. For ordinary skilled persons in the art, the specific meanings of the above terms in the utility model can be understood according to the specific circumstances.

[0038] It should be understood that although the terms "first", "second", "third" and the like can be used herein to describe various components or signals, these components or signals should not be limited by these terms. These terms are mainly used to distinguish one component from another component, or one signal from another signal. In addition, the term "or" used herein can include any one or more combinations of the associated listed items, as the case can be.

[0039] Reference Figures 1-6As shown, the embodiment of the present application provides a square battery, which comprises a cover plate 1, a current collector 2 and a shell 16, the cover plate 1 is connected with the shell 16, the current collector 2 is arranged in the shell 16, the shell 16 is provided with a battery cell, and the battery cell is provided with a tab at both ends, wherein a plurality of battery cells can be arranged in one battery, and each battery cell is provided with a positive tab and a negative tab, one positive tab is connected with one positive current collector, and one negative tab is connected with one negative current collector. The embodiment of the present application takes two battery cells arranged in one battery as an example for description, and each battery cell is connected with a positive current collector and a negative current collector. It can be understood that the number of battery cells and the number of current collectors arranged in the embodiment of the present application are only used as an example for description, and do not limit the present application.

[0040] As shown in Figures 1-3 , Figure 5 and Figure 6 , the cover plate 1 comprises a pole and a pole terminal, the side of the cover plate 1 facing the inside of the battery is provided with an insulating and heat-conducting coating 5, the end face of the pole terminal protrudes from the coating surface of the insulating and heat-conducting coating 5, the current collector 2 comprises a terminal welding part 6 and a current collection welding part 7 connected with the terminal welding part 6, the terminal welding part 6 is welded and connected with the pole terminal, the terminal welding part 6 is provided with a boss 8 protruding towards the cover plate 1, and the boss 8 abuts against the insulating and heat-conducting coating 5 on the cover plate 1.

[0041] Through the above structure, the cover plate lower plastic part does not need to be arranged in the battery, the boss 8 can make the current collector 2 and the insulating and heat-conducting coating 5 of the cover plate 1 closely contact, the insulating and heat-conducting coating 5 adopts an insulating and heat-conducting material, has good insulation and heat conduction performance, can conduct the heat in the battery to the cover plate 1, the volume of the cover plate 1 is large, can absorb a certain amount of heat, at the same time, the cover plate 1 has a large area in contact with the outside, can quickly dissipate heat, and quickly absorbs and dissipates the heat in the battery.

[0042] Specifically, referring to Figure 1 and Figure 2 , the cover plate 1 comprises a liquid injection hole and an explosion-proof hole opened in the cover plate 1, a pole and a pole terminal connected with the cover plate 1, and an insulating and heat-conducting coating 5 arranged on the side of the cover plate 1 facing the inside of the battery, wherein the cover plate 1 adopts a metal material, for example, an aluminum plate, to improve the heat transfer efficiency, the pole comprises a positive pole and a negative pole arranged at intervals on the cover plate 1, and the pole terminal comprises a positive terminal 3 and a negative terminal 4 arranged at intervals on the cover plate 1.

[0043] The insulating and heat-conducting coating 5 can adopt various known insulating and heat-conducting materials to realize the rapid heat transfer to the cover plate 1, and in the embodiment of the present application, the material of the insulating and heat-conducting coating 5 is polyimide.

[0044] In one possible embodiment, the insulating and thermally conductive coating 5 can be applied to the cover plate 1 by spraying. Preferably, the thickness of the sprayed insulating and thermally conductive coating 5 is 0.3 to 1 mm. The insulating and thermally conductive coating 5 with a thickness within this range achieves the best effect, serving both insulation and heat conduction, while also eliminating the need for the lower plastic frame of the existing cover plate, thus improving the utilization rate of the battery's internal space. (Refer to...) Figure 6 As shown, due to the thinness of the insulating and thermally conductive coating 5, the end face of the negative terminal 4 protrudes from the side of the cover plate 1 facing the cell 11, that is, the end face of the negative terminal 4 protrudes from the coating surface of the insulating and thermally conductive coating 5.

[0045] Reference Figure 2 As shown, the current collector 2 includes a positive current collector and a negative current collector. The positive current collector is used to connect to the positive terminal 3, and the negative current collector is used to connect to the negative terminal 4, as shown. Figure 3 As shown, the terminal welding portion 6 has a first end extending in a first direction. When the terminal welding portion 6 is connected to the electrode terminal, the side of the terminal welding portion 6 facing the electrode terminal is a welding surface for welding to the electrode terminal. A welding position 10 for welding to the electrode terminal is provided on the welding surface. The size and shape of the welding position 10 are set according to the size of the electrode terminal. In order to reduce the weight of the current collector 2, the welding position 10 is located near the first end of the terminal welding portion 6. In this embodiment, the first direction is the length direction of the battery cell.

[0046] In one possible embodiment, the welding position 10 is provided with a first through hole 14 to increase the surface area of ​​the conductor, enhance the conductivity of the metal, reduce the weight of the current collector, and increase the energy density. The first through hole 14 can be of any shape, and its size is such that a distance of 1-5 mm is reserved between the periphery of the first through hole 14 and the edge of the welding position 10 for welding to the terminal of the electrode post.

[0047] The cover plate 1 and the current collector 2 are welded together via electrode terminals and terminal welding parts 6. Because the insulating and thermally conductive coating 5 is thin, the end face of the electrode terminal protrudes beyond the coating surface of the insulating and thermally conductive coating 5. To enable the insulating and thermally conductive coating 5 to contact the terminal welding parts 6 for rapid heat conduction, a boss 8 is provided on the terminal welding parts 6. (Refer to...) Figure 3 and Figure 4 The boss 8 is provided at the second end of the terminal welding part 6. The boss 8 protrudes in a direction away from the welding surface of the terminal welding part 6. In order to make the boss 8 abut against the insulating and thermally conductive coating 5 on the cover plate 1 when the terminal welding part 6 is welded to the pole terminal, the height difference between the plane of the boss 8 and the plane of the terminal welding part 6 is greater than the height difference between the end face of the pole terminal and the coating surface of the insulating and thermally conductive coating 5.

[0048] The end face of the pole terminal and the coated face of the insulating and heat-conducting coating 5 form a first height difference, and the plane of the boss 8 and the plane of the terminal welding portion 6 form a second height difference. In order to achieve the best heat-conducting effect after the current collecting member 2 is connected to the cover plate 1, the first height difference is 0.4-0.6 mm, the second height difference is 0.3-0.5 mm, and the difference between the first height difference and the second height difference is 0.05-0.1 mm.

[0049] With reference to Figure 3 , one end of the current collecting welding portion 7 is connected to the boss 8 on the side away from the terminal welding portion 6, and the other end extends in a second direction away from the boss 8. The first direction in which the terminal welding portion 6 extends is perpendicular or substantially perpendicular to the second direction in which the current collecting welding portion 7 extends, so that the current collecting member 2 can be connected to the battery cell 11 in a close fit.

[0050] As shown in Figure 3 , in order to improve the ultrasonic vibration field during welding of the current collecting welding portion 7 and the battery cell 11, three through holes 15 are arranged on the current collecting welding portion 7 in the welding area of the current collecting welding portion 7 and the tab.

[0051] In a possible embodiment, the diameter of the through hole 15 can be 1-5 mm, and the distance from the through hole 15 to the edge of the welding area is 2-4 mm. The existence of the through hole 15 affects the local ultrasonic welding effect, and can improve the situation of welding cracks at the edge of the tab.

[0052] In order to facilitate welding of the current collecting welding portion 7 and the tab, and reduce the weight of the current collecting member 2, as shown in Figure 3 and Figure 4 , in a possible embodiment, the boss 8 has an extension 9 extending from one side of the boss 8 in a third direction, and the third direction is perpendicular or substantially perpendicular to the direction in which the boss 8 protrudes from the welding surface of the terminal welding portion 6. The current collecting welding portion 7 is connected to the extension 9 of the boss 8, so that the connection between the terminal welding portion 6 and the current collecting welding portion 7 and the boss 8 is located on different planes. Therefore, the current collecting member 2 can reduce the cross-sectional area of the current collecting member 2 while meeting the overcurrent capacity, and reduce the weight of the current collecting member 2.

[0053] In order to quickly transfer heat from the current collecting welding portion 7 to the cover plate 1 through the boss 8, the width of the boss 8 is 10-30 mm. The boss 8 with a width in this range has the best heat-conducting effect.

[0054] With reference to Figure 5 and Figure 6 , the internal structure of the square battery provided in the embodiments of the present application includes a battery cell 11 and a tab arranged on the battery cell 11. The tab includes a positive tab 12 and a negative tab 13. The process of connecting the cover plate 1 and the current collecting member 2 in the above embodiments to the battery cell 11 is as follows:

[0055] 1. According to the existing process, the positive and negative materials are made into positive and negative slurry in a certain proportion, and the positive and negative slurry is evenly coated on the aluminum foil and copper foil, and the solvent is removed through the tunnel oven to make the coated positive and negative sheets, and the positive and negative sheets are made through rolling, die cutting and other processes;

[0056] 2. The positive sheet, the diaphragm and the negative sheet are made into the battery core 11 through winding or stacking, including the positive lug 12 and the negative lug 13 distributed at both ends of the battery core 11;

[0057] 3. The current collector 2 is divided into positive and negative current collectors, the positive current collector is made of aluminum, the negative current collector is made of copper, the current collecting welding part 7 of the positive current collector is welded with the positive lug 12 of the battery core 11, the terminal welding part 6 is welded with the positive terminal 3, and the boss 8 on the positive current collector is in close contact with the insulating and heat-conducting coating 5 on the cover plate 1 after welding. The current collecting welding part 7 of the negative current collector is welded with the negative lug 13 of the battery core 11, the terminal welding part 6 is welded with the negative terminal 4, and the boss 8 on the negative current collector is in close contact with the insulating and heat-conducting coating 5 on the cover plate 1 after welding.

[0058] 4. According to the existing technology, the liquid injection, formation, capacity distribution and other processes of the battery are completed, and the battery manufacturing is completed.

[0059] The principle and implementation mode of the utility model are described in the specific embodiments, and the above embodiment is only used to help understand the method and core idea of the utility model; meanwhile, for the general technical personnel in the field, according to the idea of the utility model, the specific implementation mode and application range will be changed, and the above description should not be understood as the limitation of the utility model.

Claims

1. A square battery, characterized by, The application relates to a battery, which comprises: a cover plate, the cover plate comprising a pole column and a pole column terminal, the side of the cover plate facing the inside of the battery being provided with an insulating heat-conducting coating, the end face of the pole column terminal protruding from the coating face of the insulating heat-conducting coating; a current collecting piece, which comprises a terminal welding part and a current collecting welding part connected with the terminal welding part, the terminal welding part being welded with the pole column terminal, the terminal welding part being provided with a boss protruding towards the cover plate, the boss being in abutment with the insulating heat-conducting coating on the cover plate.

2. The prismatic battery of claim 1, wherein, The terminal welding part has a first end extending in a first direction, the boss is arranged at a second end of the terminal welding part, one end of the current collecting welding part is connected with the side of the boss facing away from the terminal welding part, and the other end extends in a second direction facing away from the boss, the first direction in which the terminal welding part extends being perpendicular or substantially perpendicular to the second direction in which the current collecting welding part extends.

3. A square battery according to claim 2, wherein The boss has an extension part extending in a third direction from one side of the boss, and the current collecting welding part is connected with the extension part of the boss.

4. The square battery of claim 1, wherein, The terminal welding part is provided with a welding site welded with the pole column terminal, the welding site being arranged close to the first end of the terminal welding part, and the welding site is provided with a first through hole.

5. The square battery of claim 1, wherein, The current collecting welding part is provided with at least one through hole.

6. The square battery of claim 1, wherein, The end face of the pole column terminal forms a first height difference with the coating face of the insulating heat-conducting coating, and the plane of the boss forms a second height difference with the plane of the terminal welding part, the second height difference being greater than the first height difference.

7. A square battery according to claim 6, wherein The first height difference is 0.3-0.5 mm, the second height difference is 0.4-0.6 mm, and the difference between the second height difference and the first height difference is 0.05-0.1 mm.

8. The square battery of claim 1, wherein, The thickness of the insulating heat-conducting coating is 0.3-1 mm.

9. The square battery of claim 1, wherein, The material of the insulating heat-conducting coating is polyimide.

10. The square battery of claim 1, wherein, The application further relates to a battery, which comprises: a shell, the cover plate being connected with the shell, and the current collecting piece being arranged in the shell; a battery core, the battery core being provided with a tab at both ends, and the current collecting welding part being welded with the tab.

Images