CTP battery pack

Abstract

The utility model discloses a CTP battery pack, which comprises a cold plate upper cover, a square battery cell, a uniform temperature heat conduction plate with built-in phase change material, a heat insulation plate, a lower box body, heat conduction glue and a fixing bolt, the battery cell adopts a CTP stacking structure to form a battery pack, two large side surfaces of the battery cell are respectively adhered with the uniform temperature heat conduction plate and the heat insulation plate through structural glue, and the heat conduction glue is arranged in the lower box body. Fixing pieces arranged at the two ends of the uniform-temperature heat-conducting plate are in bolted connection with the lower box body through bolts; and heat-conducting glue is filled in a gap between the cooling plate of the cold plate upper cover and the top surface of the battery pack. The CTP battery pack disclosed by the utility model is connected with the uniform-temperature heat-conducting plate of the battery pack through the fixing bolt, the system realizes high uniform temperature, the high-strength connection of the system structure of the battery pack is realized, no water-cooling pipeline is arranged in the system, the higher grouping rate and simpler production process are realized, and the upper cover adopts a cold plate upper cover, so that the battery pack can be better cooled at the upper end, and the production efficiency is improved. The battery cooling efficiency is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of CTP battery packs, in particular to a CTP battery pack. Background Art

[0002] Generally speaking, the battery packs equipped on electric vehicles are composed of battery packs assembled into modules (Module) and then installed in battery packs (Pack), forming a three-level assembly mode of battery pack-module-battery pack. CTP battery pack, namely Cell To PACK (battery-battery pack), directly integrates the battery into the battery pack, thereby eliminating the intermediate module structure, simplifying the structure of the PACK, and improving space utilization.

[0003] The CTP battery pack can save or reduce the end plates, side plates and fasteners such as screws used to fix the modules, which can improve the volume utilization rate. Due to the reduction of parts, the weight is reduced, so the mass energy density can also be improved, and the vehicle's cruising range can also be improved. Since the assembly process of the CTP battery pack is simpler, it saves manufacturing costs such as manpower and material resources, and the cost of the battery pack is reduced, and the cost of the battery pack is also reduced. However, the elimination of the module link will also bring many risks. For example, the CTP battery pack has higher requirements for the consistency of the battery cell. The deformation and deterioration of the heat dissipation performance of the battery cell caused by the expansion of the charge and discharge need to be considered at the level of the entire battery pack. In the prior art, in order to solve the problem of deformation and deterioration of the heat dissipation performance of the battery cell caused by the expansion of the charge and discharge, some battery packs adopt a large-surface cooling solution for the battery cell. The cooling system is composed of multiple harmonica tubes in parallel, and the parallel pipes are located on the left and right sides of the battery pack. Under this cooling technology, the number of cold plates is large, the energy required for the cycle is high, and it is easy to cause excessive energy consumption during normal daily use. The water-cooling pipe connections on both sides take up more space in the battery pack, resulting in a low grouping rate; the cold plate has no mechanical connection, and the strength of the system may be low; due to the large number of parallel pipes and branches, the flow distribution in the system may not be very uniform, resulting in temperature differences, and the temperature uniformity in the system is difficult to guarantee. In addition, the system has many cold plate pipes, which can easily cause excessive flow resistance, and may cause after the battery cell expands, and the cold plate connection process is more complicated. Utility Model Content

[0004] The purpose of the present invention is to overcome the above-mentioned deficiencies and defects of the prior art and to provide a CTP battery pack. The battery pack of the present invention can cool the battery system with lower energy consumption and can make the overall system more temperature-uniform.

[0005] A CTP battery pack comprises a cold plate upper cover, a square battery cell, a temperature-averaging heat-conducting plate with built-in phase change material, a heat insulation plate, a lower box, thermal adhesive and fixing bolts. The battery cell adopts a CTP stacking structure to form a battery pack, and the two large side surfaces of the battery cell are respectively bonded to the temperature-averaging heat-conducting plate and the heat insulation plate by structural adhesive. The fixings arranged at both ends of the temperature-averaging heat-conducting plate are bolted to the lower box, and the gap between the cooling plate on the cold plate upper cover and the top surface of the battery pack is filled with thermal adhesive.

[0006] Optionally, the upper cover of the cold plate is an integrated punched structure, and a double-layer structure is formed by connecting an upper flow channel plate and a lower cooling plate.

[0007] Optionally, the uniform temperature heat conductive plate and the heat insulating plate each fully cover a large surface corresponding to the battery cell.

[0008] Optionally, at least one cavity is provided inside the temperature-uniform heat-conducting plate, and a phase change material is arranged in the cavity.

[0009] Optionally, a bottom side of the fixing piece has a convex portion, and the convex portion has a stud fixing hole.

[0010] Optionally, the upper and lower ends of the uniform temperature heat conductive plate respectively form a T-shaped structure with the main body of the uniform temperature heat conductive plate, so that the uniform temperature heat conductive plate as a whole has an I-shaped structure, and the upper and lower ends of the battery cells are respectively in contact with the corresponding surfaces of the upper and lower ends of the uniform temperature heat conductive plate.

[0011] Optionally, the upper end of the temperature-averaging heat-conducting plate is in contact with and connected to the lower surface of the cooling plate on the upper cover of the cold plate, and the lower end of the temperature-averaging heat-conducting plate is in contact with and connected to the bottom plate of the lower box.

[0012] Optionally, a plurality of lower brackets are arranged at the bottom of the battery pack to support inverted battery cells, and the battery cells are inverted on the lower brackets. A bottom exhaust channel, battery cell poles and explosion-proof valve avoidance holes are formed on the lower brackets. The number of the battery cell poles and the explosion-proof valve avoidance holes is the same as the number of the battery cells, and the bottom exhaust channel is communicated with the battery cell poles and the explosion-proof valve avoidance holes.

[0013] Optionally, the bottom exhaust passage is communicated with a box exhaust passage formed in the lower box, and the box exhaust passage is communicated with the external environment of the lower box.

[0014] Optionally, each of the lower brackets is bonded and fixed to two rows of the battery cells, and two adjacent lower brackets are separated by the temperature-averaging heat-conducting plate and are in contact with the temperature-averaging heat-conducting plate.

[0015] The CTP battery pack of the utility model is connected to the temperature-averaging heat-conducting plate of the battery pack by fixing bolts, so that the system realizes high temperature uniformity and high-strength connection of the battery pack system structure. There is no water cooling pipeline arrangement in the system, so a higher grouping rate and a simpler production process are achieved. The upper cover adopts a cold plate upper cover, which can better cool the battery pack at the upper end and improve the battery cooling efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is an exploded view of the CTP battery pack of the present utility model.

[0017] Figure 2 The figure is a layout diagram of the battery pack, the uniform temperature heat conduction plate and the heat insulation plate of the CTP battery pack of the present utility model.

[0018] Figure 3 This is a cross-sectional structural diagram of the CTP battery pack of the present utility model (excluding the lower box).

[0019] Figure 4 It is a cross-sectional view of the uniform temperature heat conduction plate of the CTP battery pack of the present invention.

[0020] Figure 5 It is a partial cross-sectional view of the CTP battery pack of the present utility model.

[0021] Figure 6 This is another partial cross-sectional view of the CTP battery pack of the present invention.

[0022] Figure 7 It is a schematic diagram of the lower bracket of the CTP battery pack of the present invention.

[0023] Figure 8 This is an assembly flow chart of the CTP battery pack of the present utility model. DETAILED DESCRIPTION

[0024] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0025] like Figures 1 to 7 As shown, a CTP battery pack of an embodiment of the utility model includes a cold plate upper cover 1, a square battery cell 31, a temperature-averaging heat-conducting plate 32 with a built-in phase change material, a heat insulating plate 33, a lower box 5, a thermally conductive adhesive 2 and a fixing bolt 4. The battery cell 31 adopts a CTP stacking structure to form a battery pack 3. The two large side surfaces of the battery cell 31 are respectively bonded to the temperature-averaging heat-conducting plate 32 and the heat insulating plate 33 by structural adhesive. The fixing parts 321 arranged at both ends of the temperature-averaging heat-conducting plate 32 are bolted to the lower box 5 by fixing bolts 4, and the thermally conductive adhesive 2 is filled in the gap between the cooling plate of the cold plate upper cover 1 and the top surface of the battery pack 3.

[0026] During normal driving in a high ambient temperature, when the temperature of the battery cell rises slowly, the phase change material in the heat-conducting temperature plate 31 gradually vaporizes and begins to absorb heat, which can quickly control the temperature of the battery cell from continuing to rise, and effectively control the heating of the battery cell without turning on liquid cooling; when the ambient temperature continues to rise, until the internal phase change material is completely vaporized, the liquid cooling system is turned on to cool the battery cell through the upper cover of the cold plate, which effectively reduces the energy consumption level. When the battery cell is in a fast-heating condition such as fast charging, liquid cooling and phase change cooling work together to quickly cool the battery cell.

[0027] In one embodiment, the cold plate upper cover 1 is formed by connecting an upper flow channel plate 11 and a lower cooling plate 12 (such as welding or bolting), forming a double-layer structure. A flow channel groove 111 is stamped on the lower surface of the upper flow channel plate 11, and a cooling flow channel is formed between the flow channel groove 111 and the lower cooling plate 12. In this way, when the lower cooling plate contacts the battery pack through the thermal conductive adhesive, the thermal conductive adhesive transfers heat to the battery pack 3, which can cool the upper end of the battery cell and improve the cooling efficiency of the upper end surface of the battery cell.

[0028] The cold plate upper cover 1 and the side plate of the lower box body can be fixedly connected by bolts, such as by arranging bolt holes on the periphery of the lower cooling plate 12 and on the top of the side plate of the lower box body.

[0029] The phase change material can be selected from higher aliphatic hydrocarbon materials, such as n-hexadecane, n-octadecane, paraffin, etc., or fatty acids and their ester materials, such as stearic acid, palmitic acid, etc., or crystalline hydrated salt materials such as Na2SO4·10H2O, Mn(NO3)2·6H2O, etc., or molten salt materials, LiF, NaF, CaF2, etc., or polymer materials, such as polyethylene glycol, etc.

[0030] In order to further improve the cooling effect and maintain uniform temperature, the uniform temperature heat conductive plate fully covers the large surface corresponding to the battery cell, which can improve the uniform temperature cooling effect of the battery cell. In addition, the two battery cells are separated by the heat insulation plate. If the battery cell has thermal runaway, the heat spread can be prevented. Therefore, preferably, the heat insulation plate fully covers the large surface corresponding to the battery cell, so as to better achieve the effect of preventing heat spread. The material of the heat insulation plate can be selected from foam, aerogel, etc.

[0031] In order to place the phase change material in the temperature-averaging heat-conducting plate, at least one cavity 322 is provided inside the temperature-averaging heat-conducting plate, and the selected phase change material is arranged in the cavity. The number and size of the cavity are set according to needs to meet the temperature-averaging effect. Figure 4As shown, a uniform temperature heat conduction plate with three cavities is provided, wherein the three cavities 322 are arranged in parallel from bottom to bottom and extend from one end to the other end.

[0032] In order to fix the battery pack 3 using the fixing member 321, in one embodiment, a convex portion 325 is provided on one side of the bottom of the fixing member. Preferably, the convex portion and the side of the fixing member form an L-shaped structure, and the convex portion has a stud fixing hole 326 for fixing the bolt 4, which is threadedly connected with the threaded hole on the bottom plate of the lower box 4 to fix the battery pack. Since there are multiple fixing members, multi-layer fixing of the battery pack can be achieved. The whole system relies on this multi-layer fixing, which greatly improves the strength of the system and the strength of the whole package structure. At the same time, in the fixed state, the whole system plays a great role in suppressing the expansion force of the battery cell.

[0033] In order to improve the fixing effect of the battery of the battery pack, in one embodiment, the upper end 323 and the lower end 324 (the end where the battery cell pole and the explosion-proof valve are located) of the temperature-averaging heat conductive plate respectively form a T-shaped structure with the main body of the temperature-averaging heat conductive plate, so that the temperature-averaging heat conductive plate as a whole is an I-shaped structure, and the upper end and the lower end of the battery cell are respectively in contact with the corresponding surfaces of the upper end and the lower end of the temperature-averaging heat conductive plate, so that the battery cell of the battery pack can be limited at three positions: the side, the upper end and the lower end, thereby improving the stability effect, see Figure 3 After adopting the above-mentioned uniform temperature heat conduction plate, the upper end of the uniform temperature heat conduction plate of the present application can be directly connected to the lower surface of the cooling plate on the upper cover of the cold plate, and the lower end of the uniform temperature heat conduction plate is directly connected to the bottom plate of the lower box, see Figure 3 shown.

[0034] In order to prevent the explosion of the battery cells in the battery pack from causing greater damage, in some embodiments, a plurality of lower brackets 34 are arranged at the bottom of the battery pack to support the inverted battery cells 31, and the battery cells 31 are inverted on the lower brackets 34. The lower brackets are provided with battery cell poles and explosion-proof valve avoidance holes 342, and are provided with bottom exhaust channels 341. The bottom exhaust channels are communicated with the battery cell poles and the explosion-proof valve avoidance holes. In this way, when the battery cells in the battery pack explode, the high-temperature and high-pressure gases discharged through the explosion-proof valves after the battery cell explosion can be directionally discharged at the bottom of the box body through the battery cell poles and the explosion-proof valve avoidance holes, and discharged from the battery pack area through the bottom exhaust channel and enter the lower box body to avoid heat diffusion. Preferably, the number of the battery cell poles and the explosion-proof valve avoidance holes is the same as the number of the battery cells, and the battery cell poles and the explosion-proof valve avoidance holes can also be used as positioning holes for the battery cells to locate the positions of the battery cells.

[0035] Furthermore, in some embodiments, the bottom exhaust channel 341 is communicated with the box exhaust channel 51 formed in the lower box 5, and the box exhaust channel 51 is communicated with the external environment of the lower box 5. Since the bottom exhaust channel is communicated with the box exhaust channel formed in the lower box, the box exhaust channel is communicated with the external environment of the lower box. In this way, the high-temperature and high-pressure gas discharged through the explosion-proof valve after the battery cell explodes can be discharged out of the lower box to prevent the battery box from exploding.

[0036] The box exhaust channel 51 can be arranged on the inner side of the L-shaped angle connecting the bottom plate of the lower box and the two opposite side plates. It can be formed by arranging an upper plate and a side panel connected on the inner side of the L-shaped angle to form an exhaust cavity with a rectangular cross-section. One is arranged at each end of the fixing part of the battery pack. The box exhaust channel 51 can be connected to the external environment of the box at one end or both ends to discharge the high-temperature and high-pressure gas discharged through the explosion-proof valve after the battery cell explodes out of the lower box to prevent the battery box from exploding.

[0037] Since the fixing part 321 and the box exhaust passage 51 are located on the same side, when the cross-sectional area of ​​the box exhaust passage 51 is too large, a recessed design can be made at the position of the fixing part 321 corresponding to the box exhaust passage 51 to form an avoidance groove to facilitate the fixation of the fixing part 321 to the lower box. Of course, if the cross-sectional area of ​​the box exhaust passage 51 is small and there is no interference conflict, there is no need to provide an avoidance groove.

[0038] In some embodiments, each of the lower brackets 34 is bonded and fixed to two rows of the battery cells 31 , and two adjacent lower brackets are separated by the temperature-uniform heat-conducting plate 32 and are in contact with the temperature-uniform heat-conducting plate.

[0039] The battery pack of the utility model is stacked and formed, and is bolted at a fixed point after being put into the box, eliminating the other processes such as plugging in the liquid cooling pipes. The overall production process is relatively simple, which can greatly improve the production efficiency. Moreover, since manual operation is reduced throughout the production process, the maximum degree of production automation can be achieved. The specific assembly process route is as follows: Figure 8 As shown, the battery cells are loaded and then assembled, and the battery pack is stacked to form a battery pack. The lower bracket is then loaded into the box, and the battery pack is placed on the upper end of the upper bracket to put the battery pack into the box. After that, the battery pack is mechanically fixed to the lower box by bolting with fixing bolts. Finally, thermal conductive adhesive is sprayed on the upper surface of the battery pack, and then the electrical parts are installed. After the electrical parts are installed, the cold plate upper cover is installed and fixed to the lower box. The cold plate upper cover and the lower box can be bolted and fixed, and the assembly of the battery pack is completed.

[0040] The battery cells in the battery of the utility model can improve the overall temperature uniformity performance under the latent heat effect of the heat-conducting temperature uniformity plate, so that the temperature difference of the temperature of the whole pack of battery cells is relatively low, and only the top cold plate of the cooling system participates in the cooling cycle, and there are no other cooling pipelines inside the system, so the cooling flow resistance of the overall system is small and the overall energy consumption is lower.

[0041] The above shows and describes the basic principle and main features of the utility model and the advantages of the utility model. For those skilled in the art, it is obvious that the utility model is not limited to the details of the above exemplary embodiments, and the utility model can be implemented in other specific forms without departing from the spirit or basic features of the utility model.

[0042] Therefore, no matter from which point of view, the embodiments should be regarded as illustrative and non-restrictive, and the scope of the present invention is limited by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present invention.

[0043] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. CTP battery pack, characterized in that: It includes a cold plate upper cover, a square battery cell, a uniform temperature heat conduction plate with built-in phase change material, a heat insulation plate, a lower box, thermal conductive glue and fixing bolts. The battery cell adopts a CTP stacking structure to form a battery pack. The two large side surfaces of the battery cell are respectively bonded to the uniform temperature heat conduction plate and the heat insulation plate by structural glue. The fixings arranged at both ends of the uniform temperature heat conduction plate are fixedly connected to the lower box. The gap between the cooling plate on the cold plate upper cover and the top surface of the battery pack is filled with thermal conductive glue.

2. The CTP battery pack according to claim 1, characterized in that: The cold plate upper cover is formed by connecting an upper flow channel plate and a lower cooling plate to form a double-layer structure.

3. The CTP battery pack according to claim 1, characterized in that: The temperature-averaging heat-conducting plate and the heat-insulating plate respectively fully cover the corresponding large surfaces of the battery core.

4. The CTP battery pack according to claim 1, characterized in that: At least one cavity is arranged inside the temperature-uniform heat-conducting plate, and a phase change material is arranged in the cavity.

5. The CTP battery pack according to claim 1, characterized in that: A convex portion is provided on one side of the bottom of the fixing piece, and a stud fixing hole is provided on the convex portion.

6. The CTP battery pack according to claim 1, characterized in that: The upper end and the lower end of the temperature-averaging heat conductive plate respectively form a T-shaped structure with the temperature-averaging heat conductive plate body, so that the temperature-averaging heat conductive plate as a whole has an I-shaped structure, and the upper end and the lower end of the battery cell are respectively in contact with the corresponding surfaces of the upper end and the lower end of the temperature-averaging heat conductive plate.

7. The CTP battery pack according to claim 6, characterized in that: The upper end of the temperature-averaging heat-conducting plate is in contact with and connected to the lower surface of the cooling plate on the upper cover of the cold plate, and the lower end of the temperature-averaging heat-conducting plate is in contact with and connected to the bottom plate of the lower box.

8. The CTP battery pack according to claim 1, characterized in that: A plurality of lower brackets are arranged at the bottom of the battery pack to support inverted battery cells, and the battery cells are inverted on the lower brackets; a bottom exhaust channel, battery cell poles and explosion-proof valve avoidance holes are arranged on the lower brackets, the number of the battery cell poles and the explosion-proof valve avoidance holes is the same as the number of the battery cells, and the bottom exhaust channel is communicated with the battery cell poles and the explosion-proof valve avoidance holes.

9. The CTP battery pack according to claim 8, characterized in that: The bottom exhaust passage is communicated with a box exhaust passage formed in the lower box, and the box exhaust passage is communicated with the external environment of the lower box.

10. The CTP battery pack according to claim 8, characterized in that: Each of the lower brackets is bonded and fixed to two rows of the battery cells, and two adjacent lower brackets are separated by the temperature-averaging heat-conducting plate and are in contact with the temperature-averaging heat-conducting plate.

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