Laminated lithium battery pack
By designing a specific L-shaped busbar, the problems of unstable tab connection and poor heat dissipation in stacked lithium battery packs were solved, achieving higher stability and safety.
Patent Information
- Application Number
- CN202422031427.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-21
- Publication Date
- 2025-10-21
- Estimated Expiration
- 2034-08-21
AI Technical Summary
The stacking process produces a large number of battery cells with numerous tabs, leading to difficulties and instability in connection. When multiple cells are combined, the heat generation phenomenon is severe. How can we improve connection stability and heat dissipation?
Design a specific L-shaped busbar to better connect the positive and negative terminals of the battery cell to the cover plate, and form a "U"-shaped structure through the L-shaped busbar to improve current distribution and heat dissipation path.
It enhances the reliability of the tab connection, reduces breakage, improves the stability and safety of the battery pack, and improves charging and discharging performance and heat dissipation.
Smart Images
Figure CN223462260U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to lithium ion battery technical field especially relates to a laminated lithium battery group. BACKGROUND
[0002] Lithium battery is more and more widely used due to its high specific energy, long life, green environmental protection characteristics. Lithium battery includes electric core, and the preparation process of electric core is mostly winding process at present. Compared with winding process, the energy density, safety, space utilization rate and other aspects of the electric core prepared by laminated process are superior to winding process. However, the number of pole lug of the electric core prepared by laminated process is more, leading to the connection of pole lug and cover plate is more difficult, and the stability after connection is also poorer. When multiple electric cores are combined, this phenomenon will be further deepened. In addition, when multiple electric cores are combined, the heating phenomenon will be further deepened. Therefore, how to make the electric core prepared by laminated process better connect with the cover plate, enhance the stability of connection, and how to design a structure beneficial to heat dissipation are problems to be solved. SUMMARY
[0003] The utility model aims at overcoming the problem of electric core heat dissipation and reliability in the prior art, and provides a laminated lithium battery group.
[0004] The utility model provides a laminated lithium battery group, wherein, the laminated lithium battery group 1 includes electric core 10, L type busbar 20 and cover plate 30, the electric core 10 includes electric core main body 103 and the positive lug 101 and negative lug 102 on the same side of electric core main body 103, L type busbar 20 includes positive L type busbar 201 and negative L type busbar 202;
[0005] The both sides of cover plate 30 are provided with at least one electric core 10 respectively, one end of two positive L type busbar 201 is connected with the positive lug 101 of left and right side electric core 10 respectively, the other end of two positive L type busbar 201 is connected with the bottom of cover plate 30, one end of two negative L type busbar 202 is connected with the negative lug 102 of left and right side electric core 10 respectively, the other end of two negative L type busbar 202 is connected with the bottom of cover plate 30;
[0006] The side of L type busbar 20 and electric core main body 103 is a side, the short side of vertical intersection with a side is b side, the long side of vertical intersection with a side is f side, the short side of vertical intersection with f side is e side, the short side of vertical intersection with e side is d side, the short side of vertical intersection with b side is c side, wherein, the length ratio of a side and f side is 1:1.2-1.4, the length ratio of b side and d side is 1:0.8-1.2, the length ratio of c side and e side is 1:0.8-1.
[0007] Preferably, the top of the cover plate 30 includes a positive circular pole 301 and a negative circular pole 302 on both sides and an explosion-proof valve 303 in the middle. The bottom of the cover plate 30 includes an edge raised bar 304 on both sides and a partition raised bar 305 in the middle.
[0008] Preferably, the e edges of the two positive L-shaped bus bars 201 are connected and located in the middle of the positive circular pole 301. The e edges of the two negative L-shaped bus bars 202 are connected and located in the middle of the negative circular pole 302.
[0009] Preferably, the length of the e edge is the same as the outer diameter of the positive circular pole 301 and the negative circular pole 302.
[0010] Preferably, the b edge of the L-shaped bus bar 20 is connected with the partition raised bar 305.
[0011] Preferably, the a edge of the L-shaped bus bar 20 is connected with the cell body 103.
[0012] Preferably, the f edge of the L-shaped bus bar 20 is on the outside and the b edge is on the inside.
[0013] Preferably, in the cell 10, the positive tab 101 and the negative tab 102 have the same shape and are symmetrically arranged. The distance between the positive tab 101 and the negative tab 102 is the same as the width of the partition raised bar 305.
[0014] Preferably, the cell 10 includes multiple layers of positive plates, multiple layers of separators, and multiple layers of negative plates, which are alternately stacked with each other. Each positive plate has a positive soft tab, and each negative plate has a negative soft tab.
[0015] Preferably, the positive tab 101 of the cell 10 is composed of multiple positive soft tabs, and the negative tab 102 is composed of multiple negative soft tabs. When multiple cells 10 are stacked, the positive tab 101 of each cell 10 is connected with the positive L-shaped bus bar 201 after stacking, and the negative tab 102 of each cell 10 is connected with the negative L-shaped bus bar 202 after stacking.
[0016] The laminated lithium battery group of the utility model discloses through design the positive and negative pole lug of electric core and the cover plate are connected better by the L-shaped busbar of specific shape, the reliability of connection is enhanced, the phenomenon that the pole lug breaks or produces crack is effectively reduced, the stability and security of battery group are promoted. Meanwhile, the L-shaped busbar of specific shape is also beneficial to improve the distribution situation of current in the pole piece, make the distribution of charge-discharge current more uniform. In addition, the electric core is arranged in the cover plate two sides, and the four L-shaped busbar in the middle constitutes the structure similar to 'hui' character, make the heat of battery can dissipate through the part of space, thereby the heating condition is improved well. BRIEF DESCRIPTION OF DRAWINGS
[0017] The accompanying drawings are included to provide a further understanding of the present application, and are incorporated in and constitute a part of this specification, illustrate embodiments of the present application and serve to explain the principles of the present application, but are not intended to limit the present application.
[0018] Figure 1 The utility model provides the plan, the planar view, the three view of the laminated lithium battery group of looking down of providing for the utility model;
[0019] Figure 2 The L-shaped busbar schematic view in the laminated lithium battery group provided by the utility model;
[0020] Figure 3 The electric core schematic view in the laminated lithium battery group provided by the utility model.
[0021] BRIEF DESCRIPTION OF DRAWINGS
[0022] 101, positive pole lug;102, negative pole lug;103, electric core main body;301, circular positive pole;302, circular negative pole;303, explosion-proof valve;201, positive L-shaped busbar;202, negative L-shaped busbar;304, edge protruding strip;305, separation protruding strip. DETAILED DESCRIPTION
[0023] The technical scheme of the utility model will be described in detail below in combination with the drawings and examples.
[0024] The following content specifically describes the technical scheme of the utility model, and those skilled in the art can easily understand other advantages and effects of the present application from the content disclosed in the specification. It should be noted that the diagrams provided in the following content only illustrate the basic concept of the utility model in a schematic manner, and the drawings only show the components related to the utility model, not the number, shape and size of the components when actually implemented. The type, number and proportion of each component in actual implementation can be arbitrarily changed, and the component layout type can be more complex.
[0025] In the utility model, under the condition of not being specially explained, the words such as '' same side, one end, other end, perpendicular intersection, joint, top, bottom, upper and lower sides, outer side, inner side, middle '' etc. used for indicating position are usually understood in combination with the position shown in the drawing and the position in practical application.
[0026] In combination with Figures 1-3 The utility model relates to a kind of laminated lithium battery, wherein the laminated lithium battery, the laminated lithium battery 1 includes electric core 10, L-type busbar 20 and cover plate 30, the electric core 10 includes electric core main body 103 and the positive ear 101 and negative ear 102 on the same side of the electric core main body 103, the L-type busbar 20 includes positive L-type busbar 201 and negative L-type busbar 202;
[0027] At least one electric core 10 is respectively arranged on the both sides of the cover plate 30, one end of two positive L-type busbar 201 is respectively connected with the positive ear 101 of left and right side electric core 10, the other end of two positive L-type busbar 201 is jointed and connected with the bottom of the cover plate 30;One end of two negative L-type busbar 202 is respectively connected with the negative ear 102 of left and right side electric core 10, the other end of two negative L-type busbar 202 is jointed and connected with the bottom of the cover plate 30;
[0028] The side of the L-type busbar 20 and the electric core main body 103 joint is a side, the short side perpendicular to the side is b side, the long side perpendicular to the side is f side, the short side perpendicular to the f side is e side, the short side perpendicular to the e side is d side, the short side perpendicular to the b side is c side, wherein the length ratio of a side and f side is 1:1.2-1.4, the length ratio of b side and d side is 1:0.8-1.2, the length ratio of c side and e side is 1:0.8-1.
[0029] The length ratio of each side of the L-type busbar 20 can determine the specific shape of the L-type busbar 20, and at the same time, the current flowing through the electric core, the pole piece and the L-type busbar can be more uniform according to the above length ratio, so that the electric core / battery pack has longer service life and higher power transmission efficiency. The above content has carried out the overall description of the connection relationship of each component in the laminated lithium battery of the utility model, and the following will be more specifically described in combination with Figures 1-3
[0030] Specifically, the top of the cover plate 30 includes circular positive column 301 and circular negative column 302 on the upper and lower sides and explosion-proof valve 303 located in the middle. The outer ring part of the circular positive column 301 and the circular negative column 302 is a convex ring, and the inner ring part is through, which is connected and conducted by external circuit and busbar.
[0031] Specifically, the bottom of the cover plate 30 includes the upper and lower edge protruding strips 304 and the middle partition protruding strip 305. The partition protruding strip 305 separates the positive L-shaped bus bar 201 and the negative L-shaped bus bar 202, while providing support, further enhancing the stability and reliability of the connection, and reducing the influence of the environment such as shaking and vibration on the structure of the laminated lithium battery pack.
[0032] Specifically, the e edges of the two positive L-shaped bus bars 201 are connected and located at the middle position of the circular positive pole 301. The e edges of the two negative L-shaped bus bars 202 are connected and located at the middle position of the circular negative pole 302. The e edges of the two positive L-shaped bus bars 201 are connected by welding, and the e edges of the two negative L-shaped bus bars 202 are connected by welding, which greatly improves the stability of the connection between the bus bars, and also improves the structural stability of the left and right side cells. At the same time, the welding of the four L-shaped bus bars and the bottom of the cover plate also improves the reliability of the overall structure.
[0033] Specifically, the length of the e edge is the same as the outer diameter of the circular positive pole 301 and the circular negative pole 302.
[0034] Specifically, the b edge of the L-shaped bus bar 20 is connected with the partition protruding strip 305. The a edge of the L-shaped bus bar 20 is connected with the cell body 103. The f edge of the L-shaped bus bar 20 is on the outside, and the b edge is on the inside.
[0035] Specifically, in the cell 10, the positive lug 101 and the negative lug 102 are the same shape and symmetrical in position; the distance between the positive lug 101 and the negative lug 102 is the same as the width of the partition protruding strip 305. In combination with the above content, the distance between the positive lug and the negative lug is the same as the width of the partition protruding strip, which on the one hand makes the components fit better, and on the other hand enhances the structural stability in this way.
[0036] Specifically, the positive lug 101 and the negative lug 102 are completely attached to the L-shaped bus bar 20, and the shape and size of the positive lug 101 and the negative lug 102 completely coincide with the square formed by the a edge and the b edge of the L-shaped bus bar 20. This setting is more conducive to current conduction, and complete attachment also makes the lug of the laminated lithium battery more secure and less prone to breaking.
[0037] Specifically, the battery cell 10 includes multiple layers of positive electrode sheets, multiple layers of separators, and multiple layers of negative electrode sheets. The multiple layers of positive electrode sheets, multiple layers of separators, and multiple layers of negative electrode sheets are alternately stacked. Each positive electrode sheet has a positive soft electrode tab, and each negative electrode sheet has a negative soft electrode tab. The positive electrode tab 101 of the battery cell 10 is composed of multiple overlapping positive soft electrode tabs, and the negative electrode tab 102 is composed of multiple overlapping negative soft electrode tabs. When multiple battery cells 10 are stacked, the positive electrode tab 101 of each battery cell 10 is connected to the positive electrode L-shaped busbar 201 after stacking, and the negative electrode tab 102 of each battery cell 10 is connected to the negative electrode L-shaped busbar 202 after stacking.
[0038] Specifically, the preparation method of the laminated lithium battery pack of the present invention is as follows: prepare positive electrode slurry and negative electrode slurry, apply the positive electrode slurry on aluminum foil, and then roll, strip, cut and punch to obtain positive electrode sheets. Apply the negative electrode slurry on aluminum foil, and then roll, strip, cut and punch to obtain negative electrode sheets. Multiple positive electrode sheets, multiple ceramic diaphragms, and multiple negative electrode sheets are stacked in sequence and then further assembled into battery cells. The positive and negative tabs of the battery cell (a single battery cell or a battery cell group composed of multiple battery cells stacked together) are ultrasonically welded to L-shaped busbars of a specific shape, so that the battery cells are arranged on the left and right sides of the cover plate, and the four L-shaped busbars are laser welded to the bottom of the cover plate. The positive L-shaped busbars are connected and laser welded, and the negative L-shaped busbars are connected and laser welded. The four L-shaped busbars form a structure similar to the shape of a "U".
[0039] Through the above-mentioned structural design, the utility model arranges the battery cells on both sides of the cover plate, and uses L-shaped busbars to connect the battery cells and the cover plate. While the shape of the L-shaped busbars is specially designed to evenly distribute the current and enhance the charging and discharging performance, the battery cells, the cover plate, and the L-shaped busbars can be firmly and stably connected. Compared with the simple stacking of battery cells in traditional battery packs, the utility model uses structural design to fully reserve heat dissipation space for the battery cells, tabs and busbars to dissipate heat, thereby improving the safety of the laminated lithium battery pack.
[0040] The following examples are used for illustration. Unless otherwise specified, the raw materials used in the following examples are all commercially available conventional raw materials.
[0041] Example 1
[0042] Pour lithium iron phosphate, conductive carbon black and polyvinylidene fluoride into a mixing pot at a mass ratio of 96.5:1.5:2 and stir. Add N-methylpyrrolidone in batches and stir evenly to obtain positive electrode slurry. 2The positive electrode slurry is uniformly coated on the aluminum foil with a surface density of 185 g / m2, and then is rolled, divided, cut and punched to obtain a positive electrode sheet. 2 The negative electrode slurry is uniformly coated on the aluminum foil with a surface density of 185 g / m2, and then is rolled, divided, cut and punched to obtain a negative electrode sheet.
[0043] Two prepared battery cells are taken, and the positive and negative tabs of the two battery cells are respectively welded with L-shaped bus bars (the length ratio of a side to f side is 1:1.2, the length ratio of b side to d side is 1:1, and the length ratio of c side to e side is 1:0.8) by ultrasonic welding, and then the two battery cells are respectively arranged on the left and right sides of the cover plate, and the cover plate and the L-shaped bus bar are respectively welded by laser welding, the part where the two positive L-shaped bus bars meet is welded by laser welding, and the part where the two negative L-shaped bus bars meet is welded by laser welding. Figure 1 Finally, the laminated lithium battery group shown in
[0044] Example 2
[0045] According to the method of Example 1, except that four prepared battery cells are taken, and two battery cells are respectively arranged on the left and right sides of the cover plate, and the positive and negative tabs of the two stacked battery cells are correspondingly attached, and then are welded with L-shaped bus bars (the length ratio of a side to f side is 1:1.4, the length ratio of b side to d side is 1:0.8, and the length ratio of c side to e side is 1:1) by ultrasonic welding.
[0046] The laminated lithium battery group obtained by the above examples effectively solves the problem of heat dissipation of the battery cell, has excellent charge and discharge performance, the connection between each part is firm, and the problem of tab rupture is greatly reduced.
[0047] The above detailed the preferred embodiments of the present application, but the present application is not limited thereto. Within the technical concept of the present application, various simple modifications can be made to the technical solution of the present application, including the combination of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as disclosed by the present application, and all belong to the protection scope of the present application.
Claims
1. A laminated lithium battery pack, characterized by, The laminated lithium battery pack (1) comprises a cell (10), an L-shaped bus bar (20) and a cover plate (30), the cell (10) comprises a cell body (103) and a positive tab (101) and a negative tab (102) located on the same side of the cell body (103), the L-shaped bus bar (20) comprises a positive L-shaped bus bar (201) and a negative L-shaped bus bar (202); At least one cell (10) is arranged on both sides of the cover plate (30), one end of each of the two positive L-shaped bus bars (201) is connected with the positive tab (101) of the cell (10) on the left and right sides, respectively, the other end of each of the two positive L-shaped bus bars (201) is connected with the bottom of the cover plate (30); one end of each of the two negative L-shaped bus bars (202) is connected with the negative tab (102) of the cell (10) on the left and right sides, respectively, and the other end of each of the two negative L-shaped bus bars (202) is connected with the bottom of the cover plate (30); The side of the L-shaped bus bar (20) connected with the cell body (103) is an a side, the short side perpendicular to the a side is a b side, the long side perpendicular to the a side is an f side, the short side perpendicular to the f side is an e side, the short side perpendicular to the e side is a d side, and the short side perpendicular to the b side is a c side, wherein the length ratio of the a side to the f side is 1:1.2-1.4, the length ratio of the b side to the d side is 1:0.8-1.2, and the length ratio of the c side to the e side is 1:0.8-1.
2. The laminated lithium battery pack of claim 1, wherein, The top of the cover plate (30) comprises a circular positive column (301) and a circular negative column (302) on the upper and lower sides and an explosion-proof valve (303) in the middle; And / or, the bottom of the cover plate (30) comprises edge raised strips (304) on the upper and lower sides and a partition raised strip (305) in the middle.
3. The laminated lithium battery of claim 2, wherein, The e sides of the two positive L-shaped bus bars (201) are connected and located at the middle position of the circular positive column (301); And / or, the e sides of the two negative L-shaped bus bars (202) are connected and located at the middle position of the circular negative column (302).
4. The stacked lithium battery of claim 3, wherein, The length of the e side is the same as the outer diameter of the circular positive column (301) and the circular negative column (302).
5. The laminated lithium battery of claim 2, wherein, The b side of the L-shaped bus bar (20) is connected with the partition raised strip (305).
6. The laminated lithium battery of claim 1, wherein, The a side of the L-shaped bus bar (20) is connected with the cell body (103).
7. The laminated lithium battery of claim 1, wherein, The f side of the L-shaped bus bar (20) is on the outside, and the b side is on the inside.
8. The stacked lithium battery of claim 1, wherein, In the cell (10), the positive tab (101) and the negative tab (102) are the same shape and symmetrically located; And / or, the distance between the positive tab (101) and the negative tab (102) is the same as the width of the partition raised strip (305).
9. The laminated lithium battery of claim 1, wherein, The cell (10) comprises a plurality of positive plates, a plurality of separators and a plurality of negative plates, the plurality of positive plates, the plurality of separators and the plurality of negative plates are alternately stacked, each positive plate has a positive soft tab, and each negative plate has a negative soft tab.
10. The stacked lithium battery of claim 9, wherein, The positive tab (101) of the battery cell (10) is composed of multiple positive soft tabs overlapped, and the negative tab (102) is composed of multiple negative soft tabs overlapped. When multiple battery cells (10) are stacked, the positive tab (101) of each battery cell (10) is connected to the positive L-shaped bus bar (201) after stacking, and the negative tab (102) of each battery cell (10) is connected to the negative L-shaped bus bar (202) after stacking.