Rapid temperature control type lithium ion battery

Abstract

The utility model relates to the technical field of lithium batteries, in particular to a rapid temperature control type lithium ion battery which comprises a positive electrode cover plate, a negative electrode cover plate, a shell, a battery cell, a positive electrode liquid collection cover plate and a negative electrode liquid collection cover plate, the shell comprises an inner shell body with a runway-shaped longitudinal section and a rectangular outer shell body, an arc-shaped section of the runway shape is tangent to the short edge of the rectangle, a linear section of the runway shape is partially overlapped with the long edge of the rectangle, and four independent cavities are formed at the four corners, not occupied by the inner shell body, in the outer shell body; the negative electrode liquid collecting cover plate comprises a negative electrode liquid collecting cover plate surface provided with an internal liquid passing channel and a cooling liquid collecting component; the battery cell is arranged in the inner shell, the shape of the battery cell is matched with that of the inner shell, and two opening ends of the shell are respectively connected with the positive electrode liquid collecting cover plate and the negative electrode liquid collecting cover plate in a sealing manner. According to the lithium battery, the energy density of the lithium battery is remarkably improved, the charge-discharge performance is improved, the problem of poor heat dissipation performance of the battery core is solved, the production efficiency of the battery is high, and the manufacturing cost is low.

Description

Technical Field

[0001] The utility model relates to the technical field of lithium batteries, in particular to a fast temperature-controlled lithium-ion battery. Background Art

[0002] Lithium batteries are an essential part of electric vehicles. They not only determine the cruising range and performance of electric vehicles but also directly relate to the environmental protection, energy conservation of electric vehicles and the development direction of the entire industry. Lithium batteries have the characteristic of balanced performance. Excluding the upgrading of raw materials, usually, changing the formula and process to achieve performance improvement in some aspects will inevitably lead to a decline in performance in other aspects. Therefore, most of the current technologies on the market have reached their near-theoretical levels. If further improvement is desired, fundamental innovative designs are needed.

[0003] Square lithium batteries are the mainstream batteries in electric vehicles. Models such as Roewe ERX5, NIO, and Li ONE use this type of battery. As Figure 14 shown: It is overall rectangular. Inside, there are two flat elliptical cores obtained by winding, placed side by side along the height direction of the battery. The outer shell is generally an aluminum shell formed by stamping. The positive and negative electrode terminals and the pressure relief valve are all located at the top. The energy density of the square battery is relatively high. Square lithium batteries can store more electrical energy under the same volume. However, during the manufacturing process of the flat elliptical core, there are problems of complex tension regulation and poor alignment, which are not conducive to improving the battery production efficiency and reducing the manufacturing cost. Moreover, the heat dissipation capacity of the battery core is poor, and there is often a temperature difference of 10 - 20 °C between the internal temperature and the external temperature of the battery core, requiring a more complex thermal management system to ensure the stable operation of the battery, which is not conducive to the cycle life of the battery core.

[0004] In order to optimize the manufacturing process of square lithium batteries, the prior art has significantly extended the size of the battery core in the length direction to obtain a "blade battery" with a battery core length of up to 960 mm or even longer. The "blade battery", commonly known as the blade battery, has a specific structure as Figure 15 shown: It is overall rectangular, a special type of square battery. The positive and negative electrode terminals are respectively located on both sides of the battery in the length direction. The prismatic stacked core obtained by stacking is vertically placed in the length direction of the battery, with pole ears protruding at both ends. Compared with ordinary square lithium batteries, the blade battery has the advantages of high energy density, simplified structure, good heat dissipation performance, high space utilization rate, and strong safety performance. These advantages make it have broad application prospects and market competitive advantages in the fields of new energy vehicles and so on. However, stacking, especially long stacking, has problems of poor alignment, slow production speed, and low yield during manufacturing, which are not conducive to improving the battery production efficiency and reducing the manufacturing cost; the stacked core, especially the long stacked core, has problems of easy deformation and difficulty in entering the shell during manufacturing, which are also not conducive to improving the battery production efficiency and reducing the manufacturing cost.

[0005] Therefore, this application is proposed. Content of the Utility Model

[0006] In view of the above-mentioned shortcomings of the prior art, the present utility model provides a fast temperature-controlled lithium-ion battery.

[0007] In order to achieve the above object, the main technical solutions adopted by the present utility model include:

[0008] A fast temperature-controlled lithium-ion battery, comprising: a positive electrode cover plate, a negative electrode cover plate, a housing and an electric core. The electric core includes a wound core and a core rod. Positive electrode tabs and negative electrode tabs are provided on opposite sides of the wound core. The positive electrode tab is connected to the positive electrode cover plate, and the negative electrode tab is connected to the negative electrode cover plate. It also includes a positive liquid collecting cover plate and a negative liquid collecting cover plate with the same structure;

[0009] The housing includes an inner housing and an outer housing that are both open at opposite ends and are both hollow structures. The longitudinal section of the inner housing is in a runway shape, and the longitudinal section of the outer housing is in a rectangular shape. The arc section of the runway shape is tangent to the short side of the rectangle, and the straight section of the runway shape partially coincides with the long side of the rectangle. Four independent cavities are formed at the four corners of the outer housing that are not occupied by the inner housing;

[0010] The negative liquid collecting cover plate includes a negative liquid collecting cover plate surface. An internal liquid passing channel is provided inside the negative liquid collecting cover plate surface. A coolant collecting and flowing component is provided on the outer surface of the negative liquid collecting cover plate surface. Four negative liquid collecting cover plate connecting blocks that are partially extended are formed at the four corners of the inner surface of the negative liquid collecting cover plate surface and are matched with the cavity structure. A housing coolant channel is provided inside the negative liquid collecting cover plate connecting block. The housing coolant channel is communicated with the coolant collecting and flowing component through the internal liquid passing channel:

[0011] The electric core is placed inside the inner housing, and the shape of the electric core matches the shape of the inner housing. The two open ends of the housing are respectively sealed and connected to the positive liquid collecting cover plate and the negative liquid collecting cover plate.

[0012] Preferably, there are at least two internal liquid passing channels. The two internal liquid passing channels are arranged opposite to each other along the two long sides of the negative liquid collecting cover plate surface. The two ends of the internal liquid passing channel are respectively communicated with the two housing coolant channels, and the middle part of the internal liquid passing channel is communicated with the coolant collecting and flowing component.

[0013] Preferably, the coolant collecting and flowing component includes an integrally formed converging part, a collecting part and a collecting nozzle. The converging part is communicated with the internal liquid passing channel, and the converging part, the collecting part and the collecting nozzle form a stepped drainage cavity.

[0014] Preferably, the core includes a positive electrode sheet, a negative electrode sheet, and a separator. The positive electrode sheet includes a positive current collector and a positive active material layer. There is an area Ⅰ on the positive current collector where the positive active material layer is not coated, and area Ⅰ forms the positive electrode tab. The negative electrode sheet includes a negative current collector and a negative active material layer. There is an area Ⅱ on the negative current collector where the negative active material layer is not coated, and area Ⅱ forms the negative electrode tab. The positive electrode sheet and the negative electrode sheet are attached to both sides of the separator. The stacked positive electrode sheet, separator, and negative electrode sheet are wound around a mandrel to form a core, and the positive electrode tab and the negative electrode tab are respectively located at both ends of the core. A plurality of notches are cut at regular intervals on both area Ⅰ and area Ⅱ. After the plurality of notches are superimposed, two relatively arranged and fan-shaped grooves are respectively formed at both ends of the core.

[0015] Preferably, the two grooves located at the same end of the core are both provided in the middle of the arc section of the core.

[0016] Preferably, the arc angle radius R2 of the arc section of the core satisfies: 0mm < R2 ≤ 100mm, and the central angle α of the fan shape satisfies: 10° ≤ α ≤ 180°; the longitudinal section of the mandrel is in a runway-shaped structure, and the arc angle radius R4 and radian β of the arc section of the runway-shaped structure satisfy: 0 < R4 ≤ 100mm, 10° ≤ β ≤ 180°.

[0017] Preferably, a plurality of liquid passing channels penetrating the mandrel and communicating with the coolant collecting and distributing assembly are arranged along the length direction of the mandrel.

[0018] Preferably, a positioning hole is provided at the center of the runway-shaped structure. The radius R3 of the positioning hole satisfies 1mm ≤ R3 ≤ 100mm. A plurality of liquid passing channels are symmetrically arranged on the upper and lower sides of the positioning hole. The longitudinal section of the liquid passing channel is a kidney-shaped hole, and the height H4 and thickness T5 of the kidney-shaped hole satisfy: 1mm ≤ H4 ≤ 160mm, 1mm ≤ T5 ≤ 160mm.

[0019] Preferably, the housing is an integrally formed structure, and the material is selected from any one of steel, aluminum alloy, copper alloy, and magnesium alloy. The thickness T2 of the outer housing satisfies: 0.2mm ≤ T2 ≤ 8mm, and the thickness T3 of the arc section of the inner housing satisfies: 0.2mm ≤ T3 ≤ 8mm. The arc angle radius R1 of the arc section of the inner housing satisfies: 0mm < R1 ≤ 100mm.

[0020] Preferably, the length L3, height H3, and thickness T6 of the mandrel satisfy: 10 mm ≤ L3 ≤ 2000 mm, 10 mm ≤ H3 ≤ 200 mm, 3 mm ≤ T6 ≤ 200 mm; the length L2, height H2, and thickness T4 of the battery core satisfy: 10 mm ≤ L2 ≤ 2000 mm, 10 mm ≤ H2 ≤ 200 mm, 10 mm ≤ T4 ≤ 200 mm; the length L1, height H1, and thickness T1 of the lithium-ion battery satisfy: 10 mm ≤ L1 ≤ 2000 mm, 10 mm ≤ H1 ≤ 200 mm, 10 mm ≤ T1 ≤ 200 mm.

[0021] Compared with the prior art, the present utility model has at least the following beneficial effects:

[0022] (1) The housing is an integrally formed structure by extrusion, with low processing difficulty and high production efficiency; the structure of the wound core matches that of the inner housing. The wound core is arranged in the runway-shaped inner housing in a lying manner, and it is single-chamber and single-core. On the one hand, it reduces the design difficulty of the wound core and improves the space utilization rate of the housing. On the other hand, the inner housing adapts to the wound core, which can effectively inhibit the expansion of the battery core, improve the energy density of the lithium battery, and extend the cycle life of the lithium battery;

[0023] (2) A coolant accommodation cavity is provided at the position around the battery core on the housing, which can cool the outside of the battery core. A liquid passage is provided on the mandrel, which can cool the inside of the battery core. The combination of external cooling and internal cooling can effectively improve the heat dissipation ability of the battery core, make the temperature inside and outside the battery core relatively uniform, help solve the problem of high internal temperature during high-rate charge and discharge of the battery core, and extend the cycle life of the battery core;

[0024] (3) The design structure of the all-pole ears of the battery core significantly enhances the over-current ability, helps improve the power and energy density, enhances the charge and discharge performance, and ensures the safety of the lithium battery;

[0025] (4) The obtained lithium-ion battery can meet the requirements of system integration, helps to construct a battery PACK, and improves the overall energy density of the battery PACK. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0027] Figure 1 is an exploded view of the present utility model;

[0028] Figure 2 is a schematic diagram of the external structure of the present utility model;

[0029] Figure 3 is Figure 1 a three-dimensional structural schematic diagram of the middle housing;

[0030] Figure 4 is Figure 3 the front view of

[0031] Figure 5 is Figure 1 a three-dimensional structural schematic diagram of the negative liquid collecting cover plate in

[0032] Figure 6 is Figure 5 the bottom view of

[0033] Figure 7 is Figure 5 a cross-sectional view along the middle of the coolant collecting assembly;

[0034] Figure 8 is Figure 5 a schematic diagram of the liquid collecting principle of

[0035] Figure 9 is Figure 1 the assembly schematic of the winding core and the mandrel in Figure 1 ;

[0036] Figure 10 is Figure 9 the top view of

[0037] Figure 11 is Figure 1 the assembly schematic of the winding core and the mandrel in Figure 2 ;

[0038] Figure 12 is Figure 1 a three-dimensional structural schematic diagram of the mandrel in

[0039] Figure 13 is Figure 12 the front view of

[0040] Figure 14 is a structural schematic diagram of a square battery: A is the external shape structure diagram, and B is a cross-sectional view in the height direction of A.

[0041] Figure 15 is a structural schematic diagram of a blade battery: A is the external shape structure diagram, and B is a cross-sectional view in the length direction of A.

[0042] In the figure: 1. housing; 2. positive liquid collecting cover plate; 3. negative liquid collecting cover plate; 31. coolant collecting component; 311. collecting nozzle; 312. collecting piece; 313. confluence piece; 32. explosion-proof valve reserved hole; 33. housing coolant channel; 34. terminal post reserved hole; 35. internal liquid passing channel; 36. surface of negative liquid collecting cover plate; 37. negative liquid collecting cover plate connecting block; 4. positive cover plate; 5. negative cover plate; 6. positive adapter piece; 7. negative adapter piece; 8. positive current collecting plate; 9. negative current collecting plate; 10. mandrel; 101. positioning hole; 102. liquid passing channel; 11. wound core; 111. groove; 12. inner housing; 13. outer housing; A. battery core accommodating cavity; B. coolant accommodating cavity. Detailed implementation mode

[0043] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0044] It should be noted that: the components or structures not described in detail below all adopt conventional technical means in the art.

[0045] As Figures 1 - 13 collectively shown:

[0046] The present utility model provides a fast temperature-controlled lithium-ion battery, which specifically includes: a housing 1, a positive liquid collecting cover plate 2, a negative liquid collecting cover plate 3, a positive cover plate 4, a negative cover plate 5, a positive adapter piece 6, a negative adapter piece 7, a positive current collecting plate 8, a negative current collecting plate 9, a mandrel 10 and a wound core 11. The wound core 11 is provided with a positive tab and a negative tab at both ends of the wound core 11; the positive tab is sequentially connected to the positive cover plate 4 through the positive current collecting plate 8 and the positive adapter piece 6, and the negative tab is sequentially connected to the negative cover plate 5 through the negative current collecting plate 9 and the negative adapter piece 7. The connection methods include, but are not limited to, any one or more existing connection methods such as welding and riveting.

[0047] The housing 1 includes an inner housing 12 and an outer housing 13 that are both hollow structures with openings at both opposite ends. The longitudinal section of the inner housing 12 is a racetrack shape, and the longitudinal section of the outer housing 13 is a rectangle. The arc section of the racetrack shape is tangent to the short side of the rectangle, and the straight section of the racetrack shape partially coincides with the long side of the rectangle. Four independent cavities are formed at the four corners of the outer housing 13 that are not occupied by the inner housing 12. The space surrounded by the inner housing 12 forms a battery core accommodating cavity A, and the cavities form a coolant accommodating cavity B.

[0048] The positive liquid collection cover plate 2 and the negative liquid collection cover plate 3 have the same structure. The negative liquid collection cover plate 3 includes a negative liquid collection cover plate surface 36. An internal liquid passage 35 is provided inside the negative liquid collection cover plate surface 36. A coolant collection component 31 is provided on the outer surface of the negative liquid collection cover plate surface 36. Four negative liquid collection cover plate connection blocks 37 that are partially extended are formed at the four corners of the inner surface of the negative liquid collection cover plate surface 36 and are matched with the cavity structure. A housing coolant passage 33 is provided inside the negative liquid collection cover plate connection block 37. The housing coolant passage 33 is communicated with the coolant collection component 31 through the internal liquid passage 35;

[0049] The winding core 11 is wound around the core rod 10 to form an electric core. The shape of the electric core matches the shape of the inner housing 12. The electric core is placed in the electric core accommodation cavity A. One open end of the housing 1 is inserted into the cavity through the negative liquid collection cover plate connection block 37 and is hermetically connected to the negative liquid collection cover plate 3, and the other open end is hermetically connected to the positive liquid collection cover plate 2.

[0050] It should be noted that:

[0051] (1) The inner housing 12 and the outer housing 13 are extrusion-molded to form an integrated housing 1, which can effectively reduce the processing difficulty, improve the dimensional compatibility and production efficiency.

[0052] (2) When the two open ends of the housing 1 are hermetically connected to the negative liquid collection cover plate 3 and the positive liquid collection cover plate 2, it is preferably assisted by glue or a rubber sealing ring to ensure the effect of the hermetic connection.

[0053] (3) An explosion-proof valve reserved hole 32 and a pole column reserved hole 34 are also provided on the negative liquid collection cover plate surface 36, and a similar design is also available on the positive liquid collection cover plate 2.

[0054] In the present utility model, the design method of the long winding core 11 and the thick electrode plate reduces the proportion of non-active substances such as current collectors and structural parts, improves the energy density fundamentally, and reduces the material cost; the electric core is arranged in the inner housing 12 that is structurally adapted to it in a lying manner to obtain a new type of square shell lithium-ion battery, which not only relieves part of the volume limitation, reduces the dimensional design difficulty, improves the space utilization rate, but also the inner housing 12 can enhance the binding force on the electric core, effectively inhibit the expansion of the electric core, and improve the energy density and cycle life of the lithium battery from external conditions. At the same time, the coolant can enter the surrounding coolant accommodation cavity B to realize the cooling of the outside of the electric core and solve the problem of high internal temperature of the high energy density electric core.

[0055] The present utility model simultaneously improves the fundamental factors and external factors affecting the energy density of lithium batteries. The lithium-ion battery obtained under the synergistic effect of the two has a high energy density, and the unique design structure of the housing can cool the outside of the battery cell, solving the problem of poor heat dissipation performance of high-energy-density battery cells, improving the cycle life of the battery cells, and more importantly, the present utility model has high production efficiency and low manufacturing cost.

[0056] As a preferred technical solution, in another embodiment of the present utility model, there are at least two internal liquid passing channels 35. The two internal liquid passing channels 35 are arranged oppositely along the two long sides of the negative electrode liquid collecting cover plate surface 36. The two ends of the internal liquid passing channel 35 are respectively communicated with the two housing coolant channels 33, and the middle part of the internal liquid passing channel 35 is communicated with the coolant collecting component 31.

[0057] As a preferred technical solution, in another embodiment of the present utility model, the coolant collecting component 31 includes an integrally formed confluence part 313, a collecting part 312 and a collecting nozzle 311. The confluence part 313 is communicated with the internal liquid passing channel 35, and the confluence part 313, the collecting part 312 and the collecting nozzle 311 form a stepped drainage cavity.

[0058] As a preferred technical solution, in another embodiment of the present utility model, the wound core 11 includes a positive electrode sheet, a negative electrode sheet and a separator. The positive electrode sheet includes a positive electrode current collector and a positive electrode active material layer. There is an area Ⅰ on the positive electrode current collector where the positive electrode active material layer is not coated, and the area Ⅰ forms the positive electrode tab. The negative electrode sheet includes a negative electrode current collector and a negative electrode active material layer. There is an area Ⅱ on the negative electrode current collector where the negative electrode active material layer is not coated, and the area Ⅱ forms the negative electrode tab. The positive electrode sheet and the negative electrode sheet are attached to both sides of the separator, and the stacked positive electrode sheet, the separator and the negative electrode sheet are wound around the mandrel 10 to form the wound core 11, and the positive electrode tab and the negative electrode tab are respectively located at both ends of the wound core 11; a plurality of notches are cut at intervals on both the area Ⅰ and the area Ⅱ, and after the plurality of notches are superimposed, two oppositely arranged and fan-shaped grooves 111 are respectively formed at both ends of the wound core 11.

[0059] The setting of the grooves 111 has at least the following functions: (1) When injecting electrolyte, the positive electrode sheet and the negative electrode sheet can quickly penetrate and absorb the electrolyte through the two pairs of grooves 111, improving the speed, consistency and uniformity of the positive electrode sheet and the negative electrode sheet in penetrating and absorbing the electrolyte, shortening the injection time, improving the cycle life of the lithium battery, and improving the production capacity of the lithium battery. (2) A pair of oppositely arranged grooves 111 at the same end can effectively eliminate the stress generated when the tabs are folded, which not only helps to reduce the defective product rate on the production line caused by the tab folding problem, improves the production efficiency and product quality, but also has a positive impact on improving the battery performance, enhancing the battery safety and extending the battery service life.

[0060] In addition, the positive electrode tab and / or the negative electrode tab can either be fully retained. The design of full tabs helps enhance the overcurrent capacity, improve the power density, rate performance, and ensure safety. Or they can be selectively cut according to a certain pattern, such that the arc-shaped segments of the racetrack shape ( Figure 10 the fan-shaped parts on both sides of the groove 111) are tabless areas, and only the rectangular segment parts of the racetrack shape ( Figure 10 the red frame parts) are retained. Moreover, the tab area can be formed by fully retaining the blank foil, or can also be formed by laser-partially cutting the edges of the blank foil into multiple single tabs with a serrated or trapezoidal shape. And for the convenience of winding, the height of the single tabs gradually increases from small to large; to avoid potential interference and short-circuit risks, there are no tabs near the mandrel; for optimizing the tab layout and connection, improving the connection efficiency and avoiding occlusion, the outside of the tabs is stepped. The stepped design can also reduce the internal resistance, avoid short circuits, disperse heat, increase the battery capacity, and is convenient for processing and reduces the scrap rate.

[0061] Furthermore, the depth of the groove 111 is the same as the height of the positive electrode tab. The setting of the groove 111 can not only improve the penetration speed of the electrolyte and improve the wettability of the positive and negative electrode plates, but also not significantly affect the conductivity of the positive electrode part and the negative electrode part.

[0062] As a preferred technical solution, in another embodiment of the present utility model, the structure of the winding core 11 matches the structure of the inner housing 12 and is also in a racetrack shape. When the arc-shaped segments of the racetrack shape are folded, the deformation is relatively large and the generated stress is also relatively large. The two grooves 111 are located in the middle of the two arc-shaped segments of the racetrack shape, which helps to maximize the elimination of the stress generated by the tab folding, and is of great significance for improving the performance of the lithium battery, enhancing the safety of the lithium battery, extending the life of the lithium battery, and improving the production process. The battery core is arranged in the housing 1 in a lying manner. The design of single cavity and single core enhances the binding force on the battery core, reduces the winding arc of the winding core 11, and thus helps to reduce the control difficulty of the winding process of the winding core 11, improve the production efficiency, and reduce the manufacturing cost.

[0063] As a preferred technical solution, in another embodiment of the present utility model, the arc angle radius R2 of the arc-shaped segment of the winding core 11 satisfies: 0 mm < R2 ≤ 100 mm, and the central angle α of the sector satisfies: 10° ≤ α ≤ 180°; the longitudinal cross-section of the mandrel 10 is in a racetrack-shaped structure, and the arc angle radius R4 and the radian β of the arc-shaped segment of the racetrack-shaped structure satisfy: 0 < R4 ≤ 100 mm, 10° ≤ β ≤ 180°.

[0064] The core rod 10 plays a supporting and guiding role in the winding process of the winding core 11. The winding core 11 is the core part of the battery cell, which is formed by alternating stacking and winding of positive and negative electrode sheets and separators. When the winding core 11 and the core rod 10 meet the above requirements, the tension of the positive and negative electrode sheets and separators is easy to control during winding, the positive and negative electrode sheets and separators are tightly combined, the flatness of the battery cell is high, and the battery cell has high yield rate and performance stability.

[0065] As a preferred technical solution, in another embodiment of the present utility model, a plurality of liquid passages 102 penetrating the core rod 10 and communicating with the coolant manifold assembly 31 are provided in the core rod 10 along its length direction.

[0066] On the basis that the shell 1 has a cooling liquid accommodating chamber B, a liquid passage 102 is additionally provided inside the core rod 10, so that liquid can flow inside the battery cell, thereby achieving the purpose of simultaneous and synchronous cooling of the inside and outside of the battery cell, and further improving the cooling effect of the battery cell.

[0067] As a preferred technical solution, in another embodiment of the present utility model, a positioning hole 101 is provided at the center of the runway-type structure, and the radius R3 of the positioning hole 101 satisfies 1mm≤R3≤100mm, and a plurality of liquid passages 102 are symmetrically arranged on the upper and lower sides of the positioning hole 101, and the longitudinal cross-section of the liquid passage 102 is a waist-shaped hole, and the height H4 and thickness T5 of the waist-shaped hole satisfy: 1mm≤H4≤160mm, 1mm≤T5≤160mm.

[0068] The positioning hole 101 is mainly provided to ensure the stability and safety of the battery cell during the manufacturing process. It can ensure the accurate position of the core rod 10 during the winding process and prevent the core rod 10 from shifting or rotating during the winding process, thereby ensuring that the positive and negative electrode sheets and the separator can be tightly wound together in a predetermined manner. It also helps to control the consistency of the size and shape of the battery cell, reduce the fluctuations in the battery cell performance caused by slight differences in the manufacturing process, and facilitate the assembly and testing of the battery cell.

[0069] The coolant can cool the inside of the battery cell through the liquid passage 102. Theoretically, the larger the size, the better the cooling effect. However, if the size is too large, it will affect the support effect of the core rod 10 on the winding core 11, which is not conducive to obtaining a qualified battery cell. The utility model finds that when the liquid passage 102 meets the above requirements, it will not have a significant adverse effect on the support effect of the core rod 10, and can fully cool the inside of the battery cell.

[0070] As a preferred technical solution, in another embodiment of the present utility model, the housing 1 is an integrally formed structure, and the material is selected from any one of steel, aluminum alloy, copper alloy, and magnesium alloy. The thickness T2 of the outer housing 13 satisfies: 0.2 mm ≤ T2 ≤ 8 mm, and the thickness T3 of the arc section of the inner housing 12 satisfies: 0.2 mm ≤ T3 ≤ 8 mm. The arc radius R1 of the arc section of the inner housing 12 satisfies: 0 mm < R1 ≤ 100 mm.

[0071] Through several creative tests, it is confirmed that under the above technical parameters, the housing 1 has a good fixing and supporting effect on the battery cell, can fully protect the battery cell. More importantly, the inner housing 12 has a good binding effect on the battery cell, can effectively inhibit the expansion of the battery cell, improve the energy density of the lithium battery and increase the cycle life of the lithium battery; the coolant accommodation cavity B around has a good cooling effect on the outside of the battery cell, can effectively improve the heat dissipation energy of the battery cell, and increase the cycle life of the battery cell.

[0072] As a preferred technical solution, in another embodiment of the present utility model, the length L3, height H3, and thickness T6 of the mandrel 10 satisfy: 10 mm ≤ L3 ≤ 2000 mm, 10 mm ≤ H3 ≤ 200 mm, 3 mm ≤ T6 ≤ 200 mm;

[0073] The length L2, height H2, and thickness T4 of the battery cell satisfy: 10 mm ≤ L2 ≤ 2000 mm, 10 mm ≤ H2 ≤ 200 mm, 10 mm ≤ T4 ≤ 200 mm;

[0074] The length L1, height H1, and thickness T1 of the lithium ion battery satisfy: 10 mm ≤ L1 ≤ 2000 mm, 10 mm ≤ H1 ≤ 200 mm, 10 mm ≤ T1 ≤ 200 mm;

[0075] For a battery cell that meets the above specification requirements, whether in terms of weight, thermal management, or safety performance, it can meet the system integration requirements, which helps to build a battery PACK and improve the overall energy density of the battery PACK.

[0076] All in all, the present utility model improves both the fundamental factors and external factors affecting the energy density of the lithium battery. The lithium ion battery obtained under the synergistic effect of the two has a high energy density, and the unique design structure of the housing can cool the outside of the battery cell, solving the problem of poor heat dissipation performance of high energy density battery cells. Finally, a fast temperature control type lithium ion battery is obtained, which has a high energy density, good heat dissipation performance of the battery cell, a long cycle life, and high production efficiency and low manufacturing cost.

[0077] Although the embodiments of the present utility model have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present utility model. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present utility model. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

Claims

1. A fast temperature-controlled lithium-ion battery, comprising: A positive electrode cover plate (4), a negative electrode cover plate (5), a housing (1), and an electric core. The electric core includes a wound core (11) and a mandrel (10). A positive electrode tab and a negative electrode tab are provided on opposite sides of the wound core (11). The positive electrode tab is connected to the positive electrode cover plate (4), and the negative electrode tab is connected to the negative electrode cover plate (5). It is characterized in that: It further includes a positive liquid collection cover plate (2) and a negative liquid collection cover plate (3) with the same structure; The housing (1) includes an inner housing (12) and an outer housing (13) that are both open at opposite ends and have a hollow structure. The longitudinal cross-section of the inner housing (12) is in a racetrack shape, and the longitudinal cross-section of the outer housing (13) is in a rectangular shape. The arc segment of the racetrack shape is tangent to the short side of the rectangle, and the straight segment of the racetrack shape partially coincides with the long side of the rectangle. Four independent cavities are formed at the four corners in the outer housing (13) that are not occupied by the inner housing (12); The negative liquid collection cover plate (3) includes a negative liquid collection cover plate surface (36). An internal liquid passage (35) is provided inside the negative liquid collection cover plate surface (36). A coolant collection assembly (31) is provided on the outer surface of the negative liquid collection cover plate surface (36). Four negative liquid collection cover plate connection blocks (37) that match the cavity structure extend partially from the four corners of the inner surface of the negative liquid collection cover plate surface (36). A housing coolant passage (33) is provided inside the negative liquid collection cover plate connection blocks (37). The housing coolant passage (33) is communicated with the coolant collection assembly (31) through the internal liquid passage (35): The electric core is placed inside the inner housing (12), and the shape of the electric core matches the shape of the inner housing (12). The two open ends of the housing (1) are hermetically connected to the positive liquid collection cover plate (2) and the negative liquid collection cover plate (3) respectively.

2. The fast temperature-controlled lithium-ion battery according to claim 1, wherein There are at least two internal liquid passages (35). The two internal liquid passages (35) are arranged opposite to each other along the two long sides of the negative liquid collection cover plate surface (36). The two ends of the internal liquid passage (35) are respectively communicated with the two housing coolant passages (33), and the middle part of the internal liquid passage (35) is communicated with the coolant collection assembly (31).

3. The fast temperature-controlled lithium-ion battery according to claim 1, wherein, The coolant collection assembly (31) includes an integrally formed confluence part (313), a collection part (312), and a collection nozzle (311). The confluence part (313) is communicated with the internal liquid passage (35). The confluence part (313), the collection part (312), and the collection nozzle (311) form a stepped drainage cavity.

4. The fast temperature-controlled lithium-ion battery according to claim 1, characterized in that, The core (11) includes a positive electrode sheet, a negative electrode sheet, and a separator. The positive electrode sheet includes a positive current collector and a positive active material layer. There is an area Ⅰ on the positive current collector where the positive active material layer is not coated, and area Ⅰ forms the positive electrode tab. The negative electrode sheet includes a negative current collector and a negative active material layer. There is an area Ⅱ on the negative current collector where the negative active material layer is not coated, and area Ⅱ forms the negative electrode tab. The positive electrode sheet and the negative electrode sheet are attached to both sides of the separator, and the stacked positive electrode sheet, the separator, and the negative electrode sheet are wound around a mandrel (10) to form a core (11), and the positive electrode tab and the negative electrode tab are respectively located at both ends of the core (11); a plurality of notches are cut at regular intervals on both area Ⅰ and area Ⅱ, and after the plurality of notches are superimposed, two relatively arranged and fan-shaped grooves (111) are respectively formed at both ends of the core (11).

5. The fast temperature-controlled lithium-ion battery according to claim 4, characterized in that, Both of the two grooves (111) located at the same end of the core (11) are provided in the middle of the arc section of the core (11).

6. The fast temperature-controlled lithium-ion battery according to claim 4, wherein, The arc angle radius R2 of the arc section of the core (11) satisfies: 0 mm < R2 ≤ 100 mm, and the central angle α of the fan shape satisfies: 10° ≤ α ≤ 180°; the longitudinal section of the mandrel (10) is in a racetrack structure, and the arc angle radius R4 and the radian β of the arc section of the racetrack structure satisfy: 0 < R4 ≤ 100 mm, 10° ≤ β ≤ 180°.

7. The fast temperature-controlled lithium-ion battery according to claim 1, characterized in that, A plurality of liquid passing channels (102) penetrating the mandrel (10) and communicating with the coolant collecting and distributing assembly (31) are arranged along the length direction inside the mandrel (10).

8. The fast temperature-controlled lithium-ion battery according to claim 6, characterized in that, A positioning hole (101) is provided at the center of the racetrack structure. The radius R3 of the positioning hole (101) satisfies 1 mm ≤ R3 ≤ 100 mm. A plurality of liquid passing channels (102) are symmetrically arranged on the upper and lower sides of the positioning hole (101). The longitudinal section of the liquid passing channel (102) is a waist-shaped hole, and the height H4 and the thickness T5 of the waist-shaped hole satisfy: 1 mm ≤ H4 ≤ 160 mm, 1 mm ≤ T5 ≤ 160 mm.

9. The fast temperature-controlled lithium-ion battery according to claim 1, wherein, The housing (1) is an integrally formed structure, and the material is selected from any one of steel, aluminum alloy, copper alloy, and magnesium alloy. The thickness T2 of the outer housing (13) satisfies: 0.2 mm ≤ T2 ≤ 8 mm, and the thickness T3 of the arc section of the inner housing (12) satisfies: 0.2 mm ≤ T3 ≤ 8 mm. The arc angle radius R1 of the arc section of the inner housing (12) satisfies: 0 mm < R1 ≤ 100 mm.

10. The fast temperature control type lithium ion battery according to any one of claims 1-9, characterized in that The length L3, height H3, and thickness T6 of the mandrel (10) satisfy: 10 mm ≤ L3 ≤ 2000 mm, 10 mm ≤ H3 ≤ 200 mm, 3 mm ≤ T6 ≤ 200 mm; The length L2, height H2, and thickness T4 of the battery cell satisfy: 10 mm ≤ L2 ≤ 2000 mm, 10 mm ≤ H2 ≤ 200 mm, 10 mm ≤ T4 ≤ 200 mm; The length L1, height H1, and thickness T1 of the lithium-ion battery satisfy: 10 mm ≤ L1 ≤ 2000 mm, 10 mm ≤ H1 ≤ 200 mm, and 10 mm ≤ T1 ≤ 200 mm.

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