Sodium ion battery pack

Abstract

The invention belongs to the technical field of battery packs, and discloses a sodium ion battery pack, an upper cover is mounted on the top wall of a lower box body, two opposite sides of a bracket are connected with the inner wall of the lower box body, a battery module comprises a plurality of sodium ion batteries, a first liquid cooling plate and a second liquid cooling plate which are connected in parallel, the first liquid cooling plate is in threaded connection with the bottom wall of the lower box body, and the second liquid cooling plate is in threaded connection with the bracket. The first liquid cooling plate is connected with a plurality of first spacing plates in parallel; the second liquid cooling plate is connected with a plurality of second spacing plates in parallel; by adopting the sodium ion battery, the material cost is reduced, the low-temperature performance is optimized, the shell is divided into an upper layer and a lower layer through the bracket, the integration efficiency is improved, the electric capacity is improved, and the bottom and double side surfaces of the sodium ion battery on the lower layer are cooled through the first liquid cooling plate and the two adjacent first spacing plates; the bottom and the double side surfaces of the sodium ion battery on the upper layer are cooled through the second liquid cooling plate and the two adjacent second spacing plates, and meanwhile, the cooling liquid flowing at the bottom and the double side surfaces of the sodium ion battery is arranged in parallel, so that the heat dissipation efficiency is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of battery pack, in particular to a sodium ion battery pack. BACKGROUND

[0002] The electrification transformation of hybrid vehicle models, extended-range vehicle models, and engineering machinery vehicles (such as forklifts, drilling machines, excavators, etc.) has become an industry consensus. Such application scenarios have multiple stringent requirements for the performance of power battery packs: not only do they need to meet the long-life requirements under frequent charge-discharge cycles and adapt to complex working conditions with high and low temperatures, but they also need to take into account cost controllability and space utilization, and at the same time, they need to ensure operation safety through efficient thermal management. Under this background, the optimization of the technical architecture of power battery packs and the innovation of core materials have become key directions for breaking through industry bottlenecks.

[0003] Currently, lithium-ion batteries are still the mainstream configuration for power battery packs in the fields of hybrid vehicles and engineering machinery, but in actual applications, they gradually expose many defects: from the perspective of material cost and supply chain, the scarcity and uneven distribution of lithium resources result in the problem of high cost of lithium-ion batteries for a long time, especially for engineering machinery scenarios which are highly sensitive to cost, it is difficult to achieve large-scale cost reduction; from the working condition adaptability, the low-temperature performance of lithium-ion batteries is insufficient, and the discharge capacity decays significantly below-20℃ environment, which cannot meet the stable operation demand of engineering machinery in cold regions.

[0004] In addition, the traditional battery pack thermal management scheme also has many problems: the mainstream cold plate liquid cooling scheme can only achieve single-sided or double-sided heat dissipation, and in the high-load operation scenario of engineering machinery, the cell temperature rise is easy to exceed 15℃, triggering passive cooling protection and causing operation interruption; while the full-immersion liquid cooling can improve the temperature uniformity, but it has defects such as high cost of cooling liquid, complex sealing process, and maintenance cost twice that of the traditional scheme, which is difficult to realize engineering promotion. SUMMARY

[0005] The purpose of the present application is to provide a sodium ion battery pack with low material cost, good low-temperature performance, and excellent thermal management effect.

[0006] To achieve this purpose, the present application adopts the following technical scheme: A sodium ion battery pack, comprising: a shell, the shell comprising an upper cover, a bracket, and a lower box body, the upper cover being circumferentially screwed to the top wall of the lower box body, and the opposite sides of the bracket being screwed to the inner walls of the lower box body; a battery module, the battery module being provided with two groups, one of which is placed in the lower box body, and the other of which is placed in the bracket, the battery module comprising a plurality of sodium ion batteries; The heat management assembly comprises a first liquid cooling plate and a second liquid cooling plate in parallel, the first liquid cooling plate is screwed to the bottom wall of the lower box, the second liquid cooling plate is screwed to the bracket, the first liquid cooling plate is parallel to several first interval plates, the second liquid cooling plate is parallel to several second interval plates, the bottom of the sodium ion battery is tightly attached to the first liquid cooling plate / second liquid cooling plate, and the opposite sides of the sodium ion battery are tightly attached to two adjacent first interval plates / second interval plates.

[0007] As preferred, the heat management assembly further comprises an inlet pipe, two distribution pipes, two outlet pipes and a return pipe, the inlet pipe communicates with the two distribution pipes, one of the distribution pipes communicates with the first liquid cooling plate and the second liquid cooling plate in sequence, the other distribution pipe communicates with one of the first interval plates and one of the second interval plates in sequence, one of the outlet pipes communicates with the other first interval plate, the other second interval plate and the return pipe in sequence, and the other outlet pipe communicates with the first liquid cooling plate, the second liquid cooling plate and the return pipe in sequence.

[0008] As preferred, the pipe diameters of the inlet pipe, the distribution pipe, the outlet pipe and the return pipe are the same, flow valves are arranged on the inlet pipe and the distribution pipe, the flow valves are connected to the BMS, the end of the inlet pipe and the end of the outlet pipe are both equipped with quick plug-in connectors, and the quick plug-in connectors are internally connected to temperature sensors of the BMS.

[0009] As preferred, the first liquid cooling plate, the second liquid cooling plate, the first interval plate and the second interval plate are tightly attached to the surface of the sodium ion battery and are combined with heat-conducting silicone rubber pads.

[0010] As preferred, the thickness of the first liquid cooling plate, the second liquid cooling plate, the first interval plate and the second interval plate is 3-10 mm, the height of the internal flow channel of the first liquid cooling plate, the second liquid cooling plate, the first interval plate and the second interval plate is 8-10 mm, the distance between two adjacent first interval plates is 15-20 mm, and the distance between two adjacent second interval plates is 15-20 mm.

[0011] As preferred, the sodium ion battery pack further comprises an electrical component assembly, the electrical component assembly comprises a supporting plate and a main circuit relay, a pre-charging relay, a pre-charging resistor, a shunt and a connecting copper bar integrated in the supporting plate, the main circuit relay, the pre-charging relay, the pre-charging resistor and the shunt are connected to the BMS, the connecting copper bar connects two battery modules, and the supporting plate is screwed to the lower box.

[0012] As preferred, the supporting plate is made of flame-retardant insulation material with a V0 rating.

[0013] As preferred, the sodium ion battery pack further comprises a bracket, the bottom wall of the lower box is connected to the bracket, and the bracket is configured to be mounted on the whole vehicle.

[0014] As preferred, the first liquid cooling plate, the second liquid cooling plate, the first spacing plate and the second spacing plate are all made of aluminum alloy.

[0015] As preferred, the lower box and the bracket are both made of HC340 / 590DP-Z low-carbon steel.

[0016] The beneficial effects of the present application are: The present application provides a sodium ion battery pack, the shell comprising an upper cover, a bracket and a lower box, the upper cover being circumferentially screwed to the top wall of the lower box, the opposite sides of the bracket being screwed to the inner wall of the lower box, and two groups of battery modules being provided, one group being placed in the lower box and the other group being placed in the bracket, the battery module comprising a plurality of sodium ion batteries, a heat management assembly comprising a first liquid cooling plate and a second liquid cooling plate in parallel, the first liquid cooling plate being screwed to the bottom wall of the lower box, the second liquid cooling plate being screwed to the bracket, the first liquid cooling plate being connected in parallel with a plurality of first spacing plates, the second liquid cooling plate being connected in parallel with a plurality of second spacing plates, the bottom of the sodium ion battery being tightly attached to the first liquid cooling plate / second liquid cooling plate, and the opposite sides of the sodium ion battery being tightly attached to two adjacent first spacing plates / second spacing plates; by using sodium ion batteries, the material cost is reduced, and the low-temperature performance is optimized; by providing the bracket, the shell is divided into two layers, the internal space of the shell is fully utilized, the integration efficiency is improved, and thus the electric quantity is improved; the bottom + double sides of the sodium ion batteries in the lower layer are cooled by the first liquid cooling plate and two adjacent first spacing plates, the bottom + double sides of the sodium ion batteries in the upper layer are cooled by the second liquid cooling plate and two adjacent second spacing plates, and the cooling liquid flowing at the bottom + double sides of the sodium ion batteries is arranged in parallel, thereby reducing the temperature difference of the sodium ion batteries, improving the heat dissipation efficiency, and optimizing the heat management effect. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 is a partial structure schematic diagram of a sodium ion battery pack provided by an embodiment of the present application Figure 1 ; Figure 2 is a structure schematic diagram of a sodium ion battery pack provided by an embodiment of the present application Figure 3 is an explosion schematic diagram of a sodium ion battery pack provided by an embodiment of the present application Figure 4 is a partial structure schematic diagram of a sodium ion battery pack provided by an embodiment of the present application Figure 2 ; Figure 5 is a structure schematic diagram of a heat management assembly provided by an embodiment of the present application Figure 6 is a cooling liquid flow chart of a thermal management assembly provided by an embodiment of the present application; Figure 7 is a structural schematic diagram of an electrical component provided by an embodiment of the present application.

[0018] In the figure: 1, housing; 11, upper cover; 12, bracket; 13, lower box body; 131, high-voltage connector; 132, low-voltage connector; 133, explosion-proof valve; 2, battery module; 3, thermal management assembly; 31, first liquid cooling plate; 32, second liquid cooling plate; 33, first partition plate; 34, second partition plate; 35, liquid inlet pipe; 36, liquid distribution pipe; 37, liquid outlet pipe; 38, liquid return pipe; 41, BMS; 42, BMS slave; 5, quick plug; 6, electrical component; 61, support plate; 62, main circuit relay; 63, pre-charging relay; 64, pre-charging resistor; 65, shunt; 66, connecting copper bar; 7, bracket; 8, acquisition wire harness. DETAILED DESCRIPTION

[0019] The present application will be further described below in conjunction with the drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the present application, and not to limit the present application. In addition, it should be noted that, for the sake of description, only the parts related to the present application are shown in the drawings, not all the structures.

[0020] In the description of the present application, unless otherwise explicitly specified and limited, the terms "connected", "connected", "fixed" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0021] In the present application, unless otherwise explicitly specified and limited, the "upper" or "lower" of the first feature to the second feature can include the direct contact of the first and second features, or can include the contact of the first and second features through another feature between them. Moreover, the "upper", "upper" and "upper" of the first feature to the second feature include the vertical direction of the first feature above and oblique above the second feature, or only indicate that the horizontal height of the first feature is higher than that of the second feature. The "below", "below" and "below" of the first feature to the second feature include the vertical direction of the first feature below and oblique below the second feature, or only indicate that the horizontal height of the first feature is less than that of the second feature.

[0022] In the description of the present embodiment, the terms "upper", "lower", "right", "left", and the like, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of description and simplification of operation, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning.

[0023] The present embodiment provides a sodium ion battery pack, which has low material cost, good low-temperature performance, and excellent thermal management effect.

[0024] Referring to Figures 1 to 7 The present embodiment provides a sodium ion battery pack, which has low material cost, good low-temperature performance, and excellent thermal management effect.

[0025] Specifically, referring to Figures 1 to 3 The shell 1 includes an upper cover 11, a bracket 12, and a lower box body 13. The top wall of the lower box body 13 is circumferentially spaced apart to reserve a plurality of screw holes. Corresponding screw holes are reserved in the upper cover 11, so that the upper cover 11 is screwed to the top of the lower box body 13. Further, the opposite sides of the bracket 12 are screwed to the inner walls of the lower box body 13, thereby dividing the shell 1 into two layers to fully utilize the internal space of the shell 1 and improve the integration efficiency to provide sufficient power for the whole vehicle.

[0026] Preferably, the lower box body 13 is formed into a sealed box structure by a sheet metal bending and tailor welding process, and has a protection level of IP67, which can resist outdoor rain, snow, dust, and other harsh environmental erosion. Further preferably, the lower box body 13 and the bracket 12 are made of HC340 / 590DP-Z low carbon steel, which has a yield strength of ≥340MPa and a tensile strength of ≥590MPa, and the welding joint strength reaches 450-500MPa, so that the anti-vibration acceleration of the battery pack reaches 8-10g, which can meet the requirement of 2 times the vibration test (random vibration for 12 hours in each direction, and sinusoidal constant frequency vibration for 2 hours in each direction) in the national standard GB38031-2021. After the actual measurement of the vibration of the present scheme, there is no structural deformation, no loose electrical connection, and no other performance abnormalities, which fully meets the working condition requirements of outdoor bumpy operation of engineering machinery.

[0027] Aiming at the low-frequency high-amplitude vibration spectrum unique to the operation of engineering machinery (such as excavators), the box is optimized through finite element analysis. HC340 / 590DP-Z has excellent welding performance and fatigue strength. Simulation shows that under 10g acceleration, the maximum stress is less than 75% of the material yield limit, with sufficient safety margin. The setting of the vibration test duration is based on the target engineering machinery's daily high-intensity operation, with a 1.5 times safety life design consideration.

[0028] Optionally, please continue to refer to Figure 2 and Figure 3 The sodium-ion battery pack provided by the embodiment also includes a bracket 7, and the bottom wall of the lower box 13 is connected to the bracket 7. For example, the bottom wall of the lower box 13 is screwed to the bracket 7, and mounting holes are reserved on the bracket 7 to match the installation of the whole vehicle through the mounting holes. It should be noted that the structure of the bracket 7 can be adjusted and matched according to different vehicle models, so as to adapt to multiple vehicle models.

[0029] Please refer to Figure 3 The embodiment is provided with two groups of battery modules 2, one of which is placed in the lower box 13, and the other is placed in the bracket 12. The battery modules 2 are electrically connected through the connecting copper bars 66 between the battery modules 2 to achieve the required voltage value.

[0030] Further, the battery module 2 has a square shell structure, which is easy to fix in groups and has a simple structure. Further, the battery module 2 includes a plurality of sodium-ion batteries. The embodiment has the following advantages by using sodium-ion batteries: abundant resources and low cost, sodium reserves are more than 400 times that of lithium, uniform distribution, material cost is 30%-50% lower than that of lithium batteries, and high-priced materials such as copper foil can be saved; high safety, good thermal stability, not prone to thermal runaway, supports 0V safe discharge, excellent performance in extreme tests (piercing, extrusion); excellent low-temperature performance, capacity retention rate exceeds 90% at-30℃, still maintains more than 70% capacity at-40℃; strong fast-charging capability, supports 5C fast charging (12 minutes to charge 80%), fast sodium-ion migration rate, suitable for frequent charging and discharging scenarios.

[0031] Specifically, according to the ANSYS Fluent thermal simulation analysis, when the sodium-ion battery is discharged at 10C, the heat flux density ratio of the bottom and two long sides of the sodium-ion battery exceeds 75%. If only the bottom of the sodium-ion battery is cooled, the heat accumulation of the two long sides will cause a temperature difference >5℃. If four or more sides are cooled, the structure is too complex, and the cost gain is greater than the performance benefit. Therefore, the bottom + double side of the sodium-ion battery is cooled in the embodiment, so as to achieve the optimal balance between cost and heat dissipation efficiency.

[0032] For example, please refer to Figures 4 to 6The heat management assembly 3 comprises a first liquid cooling plate 31 and a second liquid cooling plate 32 in parallel, the first liquid cooling plate 31 is screwed to the bottom wall of the lower box body 13, the second liquid cooling plate 32 is screwed to the top wall of the support 12, the first liquid cooling plate 31 is parallel to a plurality of first spacing plates 33, preferably, the first spacing plates 33 are arranged on the top wall of the first liquid cooling plate 31 and are perpendicular to the first liquid cooling plate 31, and the second liquid cooling plate 32 is parallel to a plurality of second spacing plates 34, preferably, the second spacing plates 34 are arranged on the top wall of the second liquid cooling plate 32 and are perpendicular to the second liquid cooling plate 32.

[0033] Through the above arrangement, one group of battery modules 2 is placed on the first liquid cooling plate 31, and the bottom of the sodium-ion battery is tightly attached to the first liquid cooling plate 31, and the opposite sides of the sodium-ion battery are tightly attached to two adjacent first spacing plates 33; another group of battery modules 2 is placed on the second liquid cooling plate 32, and the bottom of the sodium-ion battery is tightly attached to the second liquid cooling plate 32, and the opposite sides of the sodium-ion battery are tightly attached to two adjacent second spacing plates 34, the internal flow channels of the first liquid cooling plate 31, the second liquid cooling plate 32, the first spacing plate 33 and the second spacing plate 34 are all in flow communication with the cooling liquid, thereby being capable of cooling the bottom and double sides of the sodium-ion battery, ensuring that the sodium-ion battery can be discharged at a large rate, and the cooling liquid flowing on the bottom and double sides of the sodium-ion battery is arranged in parallel, so that the resistance deviation of each branch cooling liquid is ≤5%, the temperature difference of the sodium-ion battery is reduced, the temperature difference is controlled within 2℃, and passive cooling protection is avoided due to local overheating.

[0034] Optionally, the cooling liquid is selected from ethylene glycol antifreeze (cost 30-50 yuan / L, much lower than 300-500 yuan / L of full immersion liquid cooling agent), and the working temperature range is -40℃ to 80℃, and the cooling liquid circulation flow rate is 8-12L / min.

[0035] Optionally, the first liquid cooling plate 31, the second liquid cooling plate 32, the first spacing plate 33 and the second spacing plate 34 are made of aluminum alloy material, which helps to reduce weight and improve heat dissipation efficiency, and balances heat dissipation efficiency and space utilization. Further, the thickness of the first liquid cooling plate 31, the second liquid cooling plate 32, the first spacing plate 33 and the second spacing plate 34 is 3-10mm, the height of the internal flow channel is 8-10mm, the spacing between the two adjacent first spacing plates 33 is 15-20mm, and the spacing between the two adjacent second spacing plates 34 is 15-20mm.

[0036] The embodiment further comprises a heat-conducting silica gel pad attached to the surface of the sodium-ion battery between the first liquid cooling plate 31, the second liquid cooling plate 32, the first spacing plate 33 and the second spacing plate 34, and the heat-conducting coefficient of the heat-conducting silica gel pad is ≥1.5W / (m K), so as to further improve the heat dissipation efficiency of the sodium-ion battery.

[0037] Specifically, please continue to refer to Figure 5 The heat management assembly 3 further comprises an inlet pipe 35, two distribution pipes 36, two outlet pipes 37 and a return pipe 38. The inlet pipe 35 is connected to the two distribution pipes 36 through quick connectors. One of the distribution pipes 36 is connected to the flow channel of the first liquid cooling plate 31 and the flow channel of the second liquid cooling plate 32 through quick connectors in sequence. The other distribution pipe 36 is connected to one of the first spacing plates 33 and one of the second spacing plates 34 through quick connectors. Two quick connectors are arranged between two adjacent first spacing plates 33. The two quick connectors between the two adjacent first spacing plates 33 are used to pass in the cooling liquid at a lower temperature and to collect the cooling liquid after absorbing heat. One of the outlet pipes 37 is connected to the other first spacing plate 33, the other second spacing plate 34 and the return pipe 38 in sequence. Alternatively, one of the outlet pipes 37 is connected to the most downstream first spacing plate 33, the most downstream second spacing plate 34 and the return pipe 38 in sequence to collect the cooling liquid after absorbing heat into the return pipe 38. The other outlet pipe 37 is connected to the first liquid cooling plate 31, the second liquid cooling plate 32 and the return pipe 38 in sequence to collect the cooling liquid after absorbing heat into the return pipe 38.

[0038] In this embodiment, the quick connector between the other distribution pipe 36 and one of the first spacing plates 33, the two quick connectors between the two adjacent first spacing plates 33 are arranged at the same end in the length direction of the first spacing plate 33. The quick connector between the other distribution pipe 36 and one of the second spacing plates 34, the two quick connectors between the two adjacent second spacing plates 34 are arranged at the same end in the length direction of the second spacing plate 34. In this way, the cooling liquid can circulate in the internal flow channel of the first spacing plate 33 and the internal flow channel of the second spacing plate 34, so that the cooling liquid can be used twice and the cooling effect can be improved.

[0039] Further, the inlet pipe 35, the two distribution pipes 36, the two outlet pipes 37 and the return pipe 38 have the same pipe diameter. Flow valves are arranged on the inlet pipe 35 and the two distribution pipes 36. The flow valves are connected to the BMS 41, so that the flow rate of the cooling liquid can be adjusted by the BMS 41. Further, the end of the inlet pipe 35 and the end of the outlet pipe 37 are provided with quick plug connectors 5. The quick plug connectors 5 are internally provided with temperature sensors. The temperature sensors are used to monitor the temperature of the inlet and outlet of the cooling liquid in real time. The temperature sensors are connected to the BMS slave control 42 and further connected to the BMS 41 through the BMS slave control 42. Through the above arrangement, the temperature information data of the inlet and outlet of the cooling liquid and the temperature information data in the battery module 2 are transmitted to the BMS slave control 42 through the collection wire harness 8 and further connected to the BMS 41. The BMS 41 can adjust the flow rate and flow of the cooling liquid in time, so as to improve the heat dissipation performance.

[0040] Adaptively, the water inlet and the water outlet are arranged on the lower box 13, the quick connector 5 at the end of the liquid inlet pipe 35 is inserted into the water inlet, and the quick connector 5 at the end of the liquid outlet pipe 37 is inserted into the water outlet.

[0041] The embodiment integrates electrical devices to further improve the volume integration efficiency of the sodium ion battery pack and improve the charging capacity of the sodium ion battery pack. Specifically, refer to Figure 3 and Figure 7 A sodium ion battery pack further includes an electrical component 6, which includes a supporting plate 61 and a main circuit relay 62, a pre-charging relay 63, a pre-charging resistor 64, a shunt 65 and a connecting copper bar 66 integrated on the supporting plate 61. The main circuit relay 62, the pre-charging relay 63, the pre-charging resistor 64 and the shunt 65 are further connected to the BMS 41 through the BMS slave 42, and the connecting copper bar 66 is used to connect two battery modules 2.

[0042] Adaptively, the high-voltage connector 131 and the low-voltage connector 132 are integrated on the lower box 13, and the high-voltage connector 131 and the low-voltage connector 132 are located above the bracket 12. The supporting plate 61 is screwed to the lower box 13 and is located below the bracket 12, so that the electrical devices on the supporting plate 61 are connected to the high-voltage connector 131 and the low-voltage connector 132, and the internal space of the sodium ion battery pack is fully utilized. Preferably, the supporting plate 61 is fixed to the lower box 13 by bolts, and the distance between the fixing points is ≤150 mm to ensure the structural stability of the electrical component 6 under vibration conditions.

[0043] For example, the insulation distance between the high-voltage components and the low-voltage components in the electrical component 6 is ≥15 mm, and the supporting plate 616 is made of an insulation material with a flame retardant level of V0. A leakage detection module can also be integrated on the supporting plate 61. When the BMS 41 detects a leakage current ≥30 mA, the BMS 41 can trigger the main circuit relay 62 to open within 50 ms.

[0044] Preferably, the lower box 13 further integrates main components such as an explosion-proof valve 133. The opening pressure of the explosion-proof valve 133 is set to 0.15-0.2 MPa. In extreme cases, when the internal pressure of the sodium ion battery pack is abnormal, the explosion-proof valve 133 opens to quickly release the gas generated inside the sodium ion battery pack, avoiding deformation of the shell 1.

[0045] The sodium ion battery pack provided in the embodiment has the following beneficial effects: The sodium ion battery uses sodium ion batteries, which have a material cost 30%-50% lower than that of lithium batteries. The low-temperature performance is excellent, with a capacity retention rate exceeding 90% at -30℃ and more than 70% at -40℃. No heating and insulation are required at low temperatures, which can save heating and insulation components. At least 16 heating plates and a circle of insulation cotton on the inner wall of the shell 1 can be saved, greatly reducing the cost. Cooling the bottom and both sides of the sodium-ion battery achieves the optimal balance between cost and performance. By integrating electrical components, the volume integration efficiency of the sodium-ion battery pack is improved, the battery capacity is increased, and the elimination of heating element and insulation components further reduces the internal weight and space of the sodium-ion battery pack, thereby further improving the volume integration efficiency of the sodium-ion battery pack.

[0046] The high integration rate improves assembly efficiency; Equipped with a leakage protection structure, it improves safety. In addition, tests have shown that the capacity retention rate is ≥85% after 2000 cycles, making it suitable for frequent charge and discharge scenarios. The structure of bracket 7 can be adjusted and matched according to different car models, thus making it compatible with multiple car models.

[0047] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art will be able to make various obvious changes, readjustments, and substitutions without departing from the scope of protection of the present invention. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A sodium-ion battery pack, characterized in that, include: The housing (1) includes an upper cover (11), a bracket (12) and a lower box (13). The upper cover (11) is circumferentially screwed to the top wall of the lower box (13), and the opposite sides of the bracket (12) are screwed to the inner wall of the lower box (13). The battery module (2) has two sets, one set is placed in the lower housing (13) and the other set is placed in the bracket (12). The battery module (2) includes several sodium-ion batteries. A thermal management component (3) includes a first liquid cooling plate (31) and a second liquid cooling plate (32) connected in parallel. The first liquid cooling plate (31) is screwed to the bottom wall of the lower housing (13), and the second liquid cooling plate (32) is screwed to the bracket (12). The first liquid cooling plate (31) is connected in parallel with several first spacers (33), and the second liquid cooling plate (32) is connected in parallel with several second spacers (34). The bottom of the sodium-ion battery is in close contact with the first liquid cooling plate (31) / the second liquid cooling plate (32), and the opposite sides of the sodium-ion battery are in close contact with two adjacent first spacers (33) / the second spacers (34).

2. A sodium-ion battery pack according to claim 1, characterized in that, The thermal management component (3) further includes an inlet pipe (35), two distribution pipes (36), two outlet pipes (37), and a return pipe (38). The inlet pipe (35) is connected to the two distribution pipes (36). One distribution pipe (36) is connected to the first liquid cooling plate (31) and the second liquid cooling plate (32) in sequence. The other distribution pipe (36) is connected to one of the first spacers (33) and one of the second spacers (34) in sequence. One outlet pipe (37) is connected to the other first spacer (33), the other second spacer (34), and the return pipe (38) in sequence. The other outlet pipe (37) is connected to the first liquid cooling plate (31), the second liquid cooling plate (32), and the return pipe (38) in sequence.

3. A sodium-ion battery pack according to claim 2, characterized in that, The inlet pipe (35), the distributor pipe (36), the outlet pipe (37), and the return pipe (38) have the same diameter. Flow valves are installed on the inlet pipe (35) and the distributor pipe (36). The flow valves are connected to the BMS (41). Quick-connect connectors (5) are installed at the ends of the inlet pipe (35) and the outlet pipe (37). The quick-connect connectors (5) have a built-in temperature sensor connected to the BMS (41).

4. A sodium-ion battery pack according to claim 1, characterized in that, The first liquid cooling plate (31), the second liquid cooling plate (32), the first spacer plate (33), and the second spacer plate (34) are attached to the surface of the sodium-ion battery with a thermally conductive silicone pad.

5. A sodium-ion battery pack according to claim 1, characterized in that, The thickness of the first liquid cooling plate (31), the second liquid cooling plate (32), the first spacer plate (33), and the second spacer plate (34) is 3-10mm. The height of the internal flow channel of the first liquid cooling plate (31), the second liquid cooling plate (32), the first spacer plate (33), and the second spacer plate (34) is 8-10mm. The distance between two adjacent first spacers plate (33) is 15-20mm, and the distance between two adjacent second spacers plate (34) is 15-20mm.

6. A sodium-ion battery pack according to claim 1, characterized in that, The sodium-ion battery pack also includes an electrical component (6), which includes a tray (61) and a main circuit relay (62), a precharge relay (63), a precharge resistor (64), a shunt (65), and a connecting copper busbar (66) integrated in the tray (61). The main circuit relay (62), the precharge relay (63), the precharge resistor (64), and the shunt (65) are all connected to the BMS (41). The connecting copper busbar (66) connects two battery modules (2). The tray (61) is screwed to the lower housing (13).

7. A sodium-ion battery pack according to claim 6, characterized in that, The tray (61) is made of insulating material with a flame retardant rating of V0.

8. A sodium-ion battery pack according to claim 1, characterized in that, The sodium-ion battery pack also includes a bracket (7), the bottom wall of the lower housing (13) is connected to the bracket (7), and the bracket (7) is configured to be installed in the vehicle.

9. A sodium-ion battery pack according to claim 1, characterized in that, The first liquid cooling plate (31), the second liquid cooling plate (32), the first spacer plate (33) and the second spacer plate (34) are all made of aluminum alloy.

10. A sodium-ion battery pack according to claim 1, characterized in that, Both the lower housing (13) and the bracket (12) are made of HC340 / 590DP-Z low carbon steel.

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