Battery box and battery pack

Abstract

The invention provides a battery box and a battery pack. The battery box comprises a box body structure and a bottom plate structure, an accommodating cavity is formed between the bottom plate structure and the box body structure; an airflow channel communicated with the accommodating cavity is formed in the box body structure; wherein the plurality of battery cells are arranged at intervals to form heat dissipation gaps; and gas flowing out of the gas flow channel flows through the heat dissipation gaps for heat exchange. According to the battery pack, the heat dissipation gaps are formed, so that gas flowing out of the gas flow channel can flow through the heat dissipation gaps for heat exchange, and the heat dissipation uniformity of the multiple battery cells is further improved; according to the battery box provided by the invention, the heat dissipation mode is reasonable in design, and the heat dissipation requirement of the battery cell can be met.

Description

Technical Field

[0001] The present application relates to the technical field of battery packs, and in particular to a battery box and a battery pack. Background Art

[0002] The operating temperature of the battery cells in the battery pack has a significant impact on the overall safety, operating efficiency and service life of the battery pack.

[0003] Existing battery packs that use air cooling usually use a solution in which a fan is installed on one side of the battery pack to suck or blow air, and an air inlet and outlet are opened on the opposite side. The disadvantage of this solution is that the battery cells close to the fan have better heat dissipation due to the large air volume, while the battery cells far from the fan have poor heat dissipation, which leads to a large temperature difference between the battery cells, affecting the battery cell capacity and internal resistance, destroying the consistency of the battery cells, and affecting the performance of the battery pack. In addition, the unreasonable design of the heat dissipation duct will also make it impossible for the hot air to be quickly discharged to the outside of the battery pack, resulting in low effective heat dissipation efficiency, which seriously reduces the safety and service life of the battery pack.

[0004] Existing battery packs that use liquid cooling usually use a liquid cooling base plate solution to dissipate heat from the battery cells. The disadvantages of this solution are: the coolant flow channel structure of the cooling base plate is relatively complex, difficult to process and expensive, and because the base plate shoulders the load-bearing and liquid cooling functions, it is usually heavy and large in size, which leads to a low overall energy density of the battery pack.

[0005] In summary, existing battery packs that use air cooling or liquid cooling to dissipate heat usually cannot meet the heat dissipation requirements of the battery cells due to unreasonable design of the heat dissipation solution, resulting in excessively high temperatures inside the battery pack and increasing the risk of thermal runaway. In addition, the temperature difference between the multiple battery cells in the existing battery pack is large due to uneven heat dissipation, which in turn reduces the overall performance and service life of the battery pack.

[0006] Application Contents

[0007] The main purpose of this application is to provide a battery box and a battery pack to solve the problem that the existing battery pack has poor heat dissipation effect and uneven heat dissipation for multiple internal battery cells.

[0008] In order to achieve the above-mentioned purpose, according to one aspect of the present application, a battery box is provided, comprising: a box structure and a base plate structure; a accommodating cavity is formed between the base plate structure and the box structure, and the accommodating cavity is used to accommodate multiple battery cells; the box structure has an air flow channel connected to the accommodating cavity; wherein the multiple battery cells are arranged at intervals to form a heat dissipation gap; the gas flowing out of the air flow channel flows through the heat dissipation gap for heat exchange.

[0009] Furthermore, the air flow channel is arranged at the upper part of the box structure, and the air flow channel has a plurality of air outlets for exhausting air, the air outlets are connected to the accommodating cavity, and at least a part of the plurality of air outlets are arranged toward the battery cells or the heat dissipation gap; wherein, the box structure and the plurality of battery cells are projected from top to bottom to the same horizontal plane, and the projections of at least a part of the plurality of air outlets at least partially overlap with the projections of the plurality of heat dissipation gaps.

[0010] Furthermore, the bottom plate structure is fixedly connected to the bottom of the box structure; the bottom plate structure has a plurality of positioning grooves arranged at intervals on one side facing the accommodating cavity, and each positioning groove cooperates with at least one battery cell limiter to fix and support the battery cell; the battery cells located in different positioning grooves are arranged at intervals to form a heat dissipation gap; the bottom plate structure has a plurality of positioning protrusions on one side facing the accommodating cavity, and the bottom plate structure has a width direction and a length direction that are horizontal and perpendicular to each other; the plurality of positioning protrusions are arranged in rows and at intervals along the width direction and in columns and at intervals along the length direction to stagger and form a plurality of positioning grooves arranged in rows and columns; two adjacent positioning grooves in the same row or column are not connected; the positioning protrusions located circumferentially of a positioning groove are used to limit the battery cell located in the positioning groove.

[0011] Furthermore, the air flow channel includes a main air duct and multiple branch air ducts, and the main air duct is connected to the outside of the box structure; the extension direction of the branch air duct is arranged parallel to the length direction, and the multiple branch air ducts are respectively connected to the main air duct and are arranged at intervals along the width direction; a portion of the multiple air outlets is located on at least a portion of the multiple branch air ducts, and the air outlet is a first air outlet, and the extension direction of the first air outlet is arranged parallel to the length direction; wherein, the box structure and the multiple battery cells are projected from top to bottom to the same horizontal plane, and the projection of the first air outlet at least partially overlaps with the projection of the multiple positioning protrusions.

[0012] Furthermore, the airflow channel also includes a plurality of connecting air channels, the extension direction of the connecting air channels is arranged parallel to the width direction, and the two ends of the connecting air channels are respectively connected to the two adjacent branch air channels; the plurality of connecting air channels located between the same two adjacent branch air channels are arranged at intervals along the length direction; a portion of the plurality of air outlets is located on at least a portion of the connecting air channel, and the air outlet is a second air outlet, and the extension direction of the second air outlet is arranged parallel to the width direction; wherein, the box structure and the plurality of battery cells are projected from top to bottom to the same horizontal plane, and the projection of the second air outlet at least partially overlaps with the projection of the plurality of positioning protrusions.

[0013] Furthermore, the bottom plate structure has a plurality of positioning grooves arranged at intervals on one side facing the accommodating cavity, and the plurality of positioning grooves correspond to the plurality of battery cells one by one to fix and support the battery cells; the battery cells located in different positioning grooves are arranged at intervals to form a heat dissipation gap; the outer periphery of the battery cell is coated with a thermally conductive metal layer, and the positioning groove is also used to accommodate the melted thermally conductive metal layer on the battery cell located in the positioning groove; and / or the width of the heat dissipation gap is not less than 2 mm and not more than 6 mm.

[0014] Furthermore, the bottom plate structure includes an upper plate body, a middle plate body and a lower plate body. The middle plate body is fixedly arranged at the lower part of the upper plate body, and the middle plate body is hollowed out to support and carry the upper plate body; the lower plate body is arranged at the lower part of the middle plate body to protect and carry the upper plate body and the middle plate body.

[0015] Furthermore, the middle plate body includes a first support beam, a second support beam and a plurality of branch beams; the middle part of the first support beam is fixedly connected to the middle part of the second support beam, and the extension direction of the first support beam and the extension direction of the second support beam have an angle to form an X-shaped cross structure; the X-shaped cross structure has four hollow spaces, and at least one branch beam is arranged in each hollow space; the two ends of the branch beam are fixedly connected to the first support beam and the second support beam respectively.

[0016] Furthermore, multiple branch beams are arranged in each hollow space; the multiple branch beams located in the same hollow space are equidistant and parallel; wherein, the extension direction of the first support beam is not perpendicular to the extension direction of the second support beam; the box structure has a width direction and a length direction that are horizontal and perpendicular to each other; the extension direction of the first support beam and the extension direction of the second support beam respectively have an angle with the length direction, and the extension direction of the branch beam is parallel to the width direction.

[0017] Furthermore, the upper plate is made of aluminum alloy; and / or the middle plate is made of titanium alloy; and / or the lower plate is made of aluminum alloy, and the lower plate seals the hollow space of the middle plate.

[0018] Furthermore, the battery box also includes an air inlet fan, which is connected to the air flow channel and is used to drive the air flow into the air flow channel and flow along the air flow channel; and / or, the battery box also includes an air outlet fan, and the box structure also has an air outlet channel connected to the accommodating cavity, and the air outlet fan is connected to the air outlet channel and is used to drive the air flow from the air outlet channel to flow out of the accommodating cavity.

[0019] Furthermore, under the condition that the battery box includes an air inlet fan and an air outlet fan, the air flow channel is arranged at the upper part of the box structure, the air inlet fan is arranged at the inlet of the air flow channel, and the inlet is located at one end of the box structure; the air outlet channel is arranged at the bottom of the box structure, the air outlet fan is arranged at the outlet of the air outlet channel, and the outlet is located at the other end of the box structure.

[0020] The present application also provides a battery pack, which includes the above-mentioned battery box and multiple battery cells.

[0021] Furthermore, the bottom plate structure has a plurality of positioning grooves arranged at intervals on one side facing the accommodating cavity, and the plurality of battery cells correspond one-to-one to the plurality of positioning grooves; the outer periphery of the battery cell is coated with a thermally conductive metal layer, and the thermally conductive metal layer of at least a portion of the battery cell is located in the heat dissipation gap, and the thermally conductive metal layer is used for heat exchange.

[0022] Furthermore, the periphery of the thermally conductive metal layer is covered with a packaging flexible film; the thermally conductive metal layer melts at a temperature higher than the melting temperature; the thermally conductive metal layer is fixed on the periphery of the battery core at a temperature not higher than the melting temperature; wherein the leakage temperature is higher than the melting temperature; when the temperature of the thermally conductive metal layer is higher than the melting temperature and not higher than the leakage temperature, the interior of the packaging flexible film accommodates the thermally conductive metal layer in a molten state; when the temperature of the thermally conductive metal layer is higher than the leakage temperature, the thermally conductive metal layer in a molten state flows out of the packaging flexible film, and at this time, the positioning groove accommodates the melted thermally conductive metal layer.

[0023] In this solution, the present application provides a battery box, comprising: a box structure and a bottom plate structure; a accommodating cavity is formed between the bottom plate structure and the box structure, and the accommodating cavity is used to accommodate multiple battery cells; the box structure has an air flow channel inside that is connected to the accommodating cavity; wherein, multiple battery cells are arranged at intervals to form a heat dissipation gap; the gas flowing out of the air flow channel flows through the heat dissipation gap for heat exchange.

[0024] The present application forms a heat dissipation gap by setting up multiple battery cell spacing, so that the gas flowing out of the air flow channel can flow through the heat dissipation gap for heat exchange, thereby improving the heat dissipation uniformity of multiple battery cells; compared with the existing battery packs that use air cooling, the temperature difference between the battery cells in the present application is small, which will not destroy the consistency of the battery cells, and can quickly discharge heat to the outside of the battery box, with high effective heat dissipation efficiency, thereby ensuring the safety and service life of the battery pack; compared with the existing battery packs that use liquid cooling, the battery box of the present application has a simple structure, is easy to process and form, and is low in price. The overall energy density of the battery pack can be improved subsequently by the lightweight design of the bottom plate structure; the battery box proposed in the present application has a reasonable heat dissipation design, which can meet the requirements of battery cell heat dissipation, has a simple structure and low cost, and is suitable for promotion and use. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The drawings that constitute part of this application are used to provide a further understanding of this application. The illustrative embodiments of this application and their descriptions are used to explain this application and do not constitute an improper limitation on this application. In the drawings:

[0026] Figure 1 A partial structural diagram of a battery pack provided by an embodiment of the present application is shown;

[0027] Figure 2 A schematic diagram of the internal structure of a battery pack provided by one embodiment of the present application is shown in a front view;

[0028] Figure 3 A schematic diagram of the internal structure of a box structure provided by an embodiment of the present application when viewed from above is shown;

[0029] Figure 4 A specific structural schematic diagram of the base plate structure provided by an embodiment of the present application is shown.

[0030] The above drawings include the following reference numerals:

[0031] 10. Box structure; 11. Air flow channel; 111. Air outlet; 112. Main air channel; 113. Branch air channel; 114. Connecting air channel;

[0032] 20. Bottom plate structure; 21. Upper plate; 211. Positioning groove; 212. Positioning protrusion; 22. Middle plate; 221. First support beam; 222. Second support beam; 223. Branch beam; 23. Lower plate;

[0033] 30. Accommodation cavity;

[0034] 40. Battery cell; 41. Heat dissipation gap;

[0035] 50. Air inlet fan. DETAILED DESCRIPTION

[0036] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is in no way intended to limit the present application and its application or use. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0037] like Figures 1 to 4 As shown, the present application provides a battery box, comprising: a box structure 10 and a bottom plate structure 20; a accommodating cavity 30 is formed between the bottom plate structure 20 and the box structure 10, and the accommodating cavity 30 is used to accommodate multiple battery cells 40; the box structure 10 has an air flow channel 11 inside that is connected to the accommodating cavity 30; wherein, the multiple battery cells 40 are arranged at intervals to form a heat dissipation gap 41; the gas flowing out of the air flow channel 11 flows through the heat dissipation gap 41 for heat exchange.

[0038] The present application forms a heat dissipation gap 41 by arranging the battery cells 40 located in different positioning grooves 211 at intervals, so that the gas flowing out of the air flow channel 11 can flow through the heat dissipation gap 41 for heat exchange, thereby improving the heat dissipation uniformity of multiple battery cells 40; compared with the existing battery packs that adopt air cooling, the temperature difference between the battery cells 40 in the present application is small, which will not destroy the consistency of the battery cells 40, and can quickly discharge heat to the outside of the battery box, with high effective heat dissipation efficiency, thereby ensuring the safety and service life of the battery pack; compared with the existing battery packs that adopt liquid cooling, the battery box of the present application has a simple structure, is easy to process and shape, and is low in price. The overall energy density of the battery pack can be improved subsequently by the lightweight design of the bottom plate structure 20; the battery box proposed in the present application has a reasonable heat dissipation design, which can meet the heat dissipation requirements of the battery cells 40, has a simple structure and low cost, and is suitable for promotion and use.

[0039] In one embodiment of the present application, the bottom plate structure 20 is fixedly connected to the bottom of the box structure 10; the bottom plate structure 20 has a plurality of spaced positioning grooves 211 on the side facing the accommodating cavity 30, and each positioning groove 211 is limitedly engaged with at least one battery cell 40 to fix and support the battery cell 40; wherein, the battery cells 40 located in different positioning grooves 211 are spaced apart to form a heat dissipation gap 41. The present application provides a plurality of spaced positioning grooves 211 on the side facing the accommodating cavity 30, so that each positioning groove 211 can be limitedly engaged with at least one battery cell 40, thereby achieving fixture-free fixation and reliable support of the battery cell 40.

[0040] like Figure 2 and Figure 3 As shown, the air flow channel 11 is arranged at the upper part of the box structure 10, and the air flow channel 11 has a plurality of air outlets 111 for exhausting air, the air outlets 111 are connected to the accommodating cavity 30, and at least a part of the plurality of air outlets 111 are arranged toward the battery cell 40 or the heat dissipation gap 41; wherein, the box structure 10 and the plurality of battery cells 40 are projected from top to bottom to the same horizontal plane, and the projection of at least a part of the plurality of air outlets 111 at least partially overlaps with the projection of the plurality of heat dissipation gaps 41.

[0041] By arranging multiple air outlets 111 on the upper part of the box structure 10, it is ensured that the airflow can be evenly distributed to the surface of each battery cell 40, especially those battery cells 40 located in the middle and deep part of the box structure 10; the layout of the air outlets 111 matches the position of the heat dissipation gap 41, so that the airflow can directly pass through the heat dissipation gap 41 and contact the surface of the battery cell 40, thereby improving the convective heat dissipation efficiency; the above design makes the airflow distribution inside the box structure 10 more uniform, and each battery cell 40 can be effectively cooled, thereby reducing the temperature difference between the battery cells 40 and improving the overall performance of the battery pack.

[0042] Application scenarios include but are not limited to power battery systems of electric vehicles, and industrial energy storage systems that require high heat dissipation efficiency and temperature uniformity; the actual use process includes starting the ventilation system of the battery box (such as the air intake fan 50), and the air flow enters from the entrance of the air flow channel 11, passes through multiple air outlets 111, and finally exchanges heat with the battery cell 40 through the heat dissipation gap 41 to achieve the purpose of heat dissipation.

[0043] like Figure 1 and Figure 4 As shown, the bottom plate structure 20 has a plurality of positioning protrusions 212 on one side facing the accommodating cavity 30, and the bottom plate structure 20 has a width direction and a length direction along the horizontal direction and perpendicular to each other; the plurality of positioning protrusions 212 are arranged in rows along the width direction and in columns along the length direction to stagger and form a plurality of positioning grooves 211 arranged in rows and columns; two adjacent positioning grooves 211 in the same row or column are not connected; the positioning protrusions 212 located in the circumference of a positioning groove 211 are used to limit the battery cell 40 located in the positioning groove 211.

[0044] The combined use of the positioning groove 211 and the positioning protrusion 212 is based on the efficient use of the internal space of the battery box and the need for stable fixation of the battery cell 40; by arranging the positioning protrusions 212 in rows and columns, a plurality of independent positioning grooves 211 are formed. This design not only ensures that each battery cell 40 has its own fixed position to avoid movement inside the box structure 10, but also forms a heat dissipation gap 41 through the isolation of the positioning groove 211, which is conducive to the smooth flow of airflow and improves the heat dissipation efficiency; the above design makes the internal structure of the battery box more compact, the fixation of the battery cell 40 more stable, and at the same time the heat dissipation performance is improved, reducing the risk of thermal runaway.

[0045] During actual use, the battery cells 40 are placed one by one into the corresponding positioning grooves 211 . The positioning protrusions 212 ensure the stability of the battery cells 40 in the positioning grooves 211 , while forming heat dissipation gaps 41 to create conditions for subsequent airflow heat dissipation.

[0046] In addition, it is worth noting that the above design also makes the width dimension of the positioning protrusion 212 along the width direction correspond to the width dimension of the heat dissipation gap 41 where the positioning protrusion 212 is located, and the length dimension of the positioning protrusion 212 along the length direction correspond to the length dimension of the heat dissipation gap 41 where the positioning protrusion 212 is located.

[0047] like Figure 2 and Figure 3As shown, the air flow channel 11 includes a main air channel 112 and multiple branch air channels 113, and the main air channel 112 is connected to the outside of the box structure 10; the extension direction of the branch air channel 113 is arranged parallel to the length direction, and the multiple branch air channels 113 are respectively connected to the main air channel 112, and are arranged at intervals along the width direction; a part of the multiple air outlets 111 is located on at least a part of the multiple branch air channels 113, and the air outlet 111 is a first air outlet, and the extension direction of the first air outlet is arranged parallel to the length direction; wherein, the box structure 10 and the multiple battery cells 40 are respectively projected from top to bottom to the same horizontal plane, and the projection of the first air outlet at least partially overlaps with the projection of the multiple positioning protrusions 212.

[0048] The design of the branch air duct 113 and the air outlet 111 is intended to optimize the airflow path inside the box structure 10 to ensure that the airflow can evenly cover the surfaces of all battery cells 40 and the heat dissipation gap 41; the main air duct 112 serves as the inlet of the airflow, and the branch air duct 113 is responsible for directing the airflow to different areas of the box structure 10, especially those areas where the battery cells 40 are densely packed; the setting of the first air outlet takes into account the maximization of the contact between the airflow and the circumferential surface of the battery cell 40, and by overlapping with the projection of the positioning groove 211 and the positioning protrusion 212, it ensures that the airflow can be directly blown onto the efficient heat dissipation surface of the battery cell 40 (such as the outer peripheral surface located in the heat dissipation gap 41), thereby improving the heat exchange efficiency.

[0049] The above design makes the thermal management inside the battery box more refined and the airflow distribution more uniform, effectively reducing the maximum temperature of the battery cell 40 and improving the overall stability and safety of the battery system.

[0050] In a specific embodiment of the present application, the main air duct 112 and the multiple branch air ducts 113 adopt a bionic leaf vein-shaped air duct design (for example: similar to the shape design of the main veins and branch veins on a leaf), which can effectively reduce the flow resistance between the main air duct 112 and the multiple branch air ducts 113, and ensure the uniformity of air flow diversion; the size ratio of the main air duct 112 and the multiple branch air ducts 113 can adopt the golden ratio, and then cooperate with the air inlet fan 50 and the air outlet fan to realize low-power directional airflow drive, which can effectively distribute the airflow and dissipate heat.

[0051] like Figure 2 and Figure 3As shown, the air flow channel 11 also includes a plurality of connecting air channels 114, the extension direction of the connecting air channels 114 is arranged parallel to the width direction, and the two ends of the connecting air channels 114 are respectively connected to the two adjacent branch air channels 113; the plurality of connecting air channels 114 located between the same two adjacent branch air channels 113 are spaced apart along the length direction; a portion of the plurality of air outlets 111 is located on at least a portion of the connecting air channels 114, and the air outlet 111 is a second air outlet, and the extension direction of the second air outlet is arranged parallel to the width direction; wherein, the box structure 10 and the plurality of battery cells 40 are respectively projected from top to bottom to the same horizontal plane, and the projection of the second air outlet at least partially overlaps with the projection of the plurality of positioning protrusions 212.

[0052] The design of connecting air duct 114 and the second air outlet further improves the airflow field within the battery box, ensuring uniform distribution of airflow in different directions (e.g., width and length). The provision of connecting air duct 114 allows airflow to flow freely across the width of the battery box, preventing localized airflow from being too strong or too weak. The provision of the second air outlet in conjunction with the positioning protrusion 212 ensures that airflow directly impacts the heat dissipation surface of the battery cell 40 within the heat dissipation gap 41, improving heat dissipation efficiency. This design results in a more balanced airflow distribution within the battery box and more precise temperature control of the battery cell 40, helping to extend the battery's service life and reduce the risk of thermal runaway.

[0053] Specifically, the side of the bottom plate structure 20 facing the accommodating cavity 30 has a plurality of positioning grooves 211 arranged at intervals, and the plurality of positioning grooves 211 correspond one-to-one with the plurality of battery cells 40 to fix and support the battery cells 40; the battery cells 40 located in different positioning grooves 211 are arranged at intervals to form a heat dissipation gap 41; the outer periphery of the battery cell 40 is coated with a thermally conductive metal layer, and the positioning groove 211 is also used to accommodate the melted thermally conductive metal layer on the battery cell 40 located in the positioning groove 211; and / or, the width of the heat dissipation gap 41 is not less than 2 mm and not more than 6 mm.

[0054] Through the one-to-one matching design of the positioning groove 211 and the battery cell 40, the heat dissipation efficiency is improved and the battery cell 40 is ensured to be firmly fixed; by coating the outer periphery of the battery cell 40 with a thermally conductive metal layer, not only the heat exchange efficiency between the battery cell 40 and the surrounding environment is improved, but also to a certain extent, it serves as a protective layer for the battery cell 40; when the battery cell 40 works under extreme conditions and causes the thermally conductive metal layer to melt, the positioning groove 211 can collect the molten metal to prevent it from flowing into other key parts of the battery box, avoiding short circuits or other faults; through the size design of the heat dissipation gap 41, it is ensured that the airflow can flow smoothly between the battery cells 40 to take away heat, while avoiding excessive airflow resistance and ensuring the heat dissipation effect.

[0055] This arrangement significantly enhances the thermal management capability of the battery box, and can effectively control the temperature of the battery cell 40 even under high-load working conditions, thereby improving the reliability and safety of the battery system. During actual use, the airflow takes away the heat of the battery cell 40 through the heat dissipation gap 41. Under abnormally high temperature conditions, the thermally conductive metal layer melts and is collected by the positioning groove 211 to prevent damage to the internal circuit of the battery box.

[0056] like Figure 4 As shown, the base plate structure 20 includes an upper plate body 21, a middle plate body 22 and a lower plate body 23. The middle plate body 22 is fixedly arranged at the lower part of the upper plate body 21. The middle plate body 22 is hollowed out to support and carry the upper plate body 21; the lower plate body 23 is arranged at the lower part of the middle plate body 22 to protect and carry the upper plate body 21 and the middle plate body 22.

[0057] The layered design of the bottom plate structure 20 improves the overall structural strength of the battery box and reduces its weight. The upper plate 21 serves as the direct support platform for the battery cells 40, while the middle plate 22 reduces weight through its hollowed-out structure while providing sufficient support strength to ensure the stability of the upper plate 21. The lower plate 23 protects the upper and middle plates 21 and 22 from external impacts and also acts as a seal to prevent moisture and other external factors from invading the battery box. This design makes the overall structure of the battery box more robust and effectively reduces its weight, thereby improving the energy density and safety of the battery system.

[0058] In a specific embodiment of the present application, a surface of the upper plate 21 facing the accommodating cavity 30 has a plurality of spaced positioning grooves 211 , and each positioning groove 211 is limitedly engaged with a battery cell 40 to fix and support the battery cell 40 .

[0059] In a specific embodiment of the present application, the upper plate body 21 has a plurality of positioning protrusions 212 on one side facing the accommodating cavity 30, and the upper plate body 21 has a width direction and a length direction that are horizontal and perpendicular to each other; the plurality of positioning protrusions 212 are arranged in rows along the width direction and in columns along the length direction to form a plurality of positioning grooves 211 arranged in rows and columns.

[0060] like Figure 4 As shown, the middle plate body 22 includes a first support beam 221, a second support beam 222 and a plurality of branch beams 223; the middle part of the first support beam 221 is fixedly connected to the middle part of the second support beam 222, and the extension direction of the first support beam 221 and the extension direction of the second support beam 222 have an angle to form an X-shaped cross structure; the X-shaped cross structure has four hollow spaces, and at least one branch beam 223 is provided in each hollow space; the two ends of the branch beam 223 are fixedly connected to the first support beam 221 and the second support beam 222 respectively.

[0061] The X-shaped cross-structure design of the center plate 22 achieves both lightweight and high strength. The X-shaped cross-structure formed by the first support beam 221 and the second support beam 222 not only disperses the weight of the battery cells 40 and reduces pressure on the bottom plate, but also absorbs energy during impact, protecting the battery cells 40 from damage. The provision of branch beams 223 further strengthens the structural strength of the center plate 22, ensuring stability and reliability under various load conditions. This design ensures that the battery box bottom plate structure 20 maintains sufficient strength while effectively controlling weight, improving the overall performance and safety of the battery pack.

[0062] like Figure 4 As shown, a plurality of branch beams 223 are provided in each hollow space; the plurality of branch beams 223 located in the same hollow space are equidistant and parallel to each other; wherein, the extension direction of the first support beam 221 is not perpendicular to the extension direction of the second support beam 222; the box structure 10 has a width direction and a length direction that are horizontal and perpendicular to each other; the extension direction of the first support beam 221 and the extension direction of the second support beam 222 respectively have an angle with the length direction, and the extension direction of the branch beam 223 is parallel to the width direction.

[0063] The arrangement of the branch beams 223 enhances the structural strength of the center plate 22. Equally spaced and parallel, the branch beams 223 not only evenly distribute the weight of the battery cells 40 but also facilitate processing and forming. The non-perpendicular angle between the first and second support beams 221, 222 allows the center plate 22 to disperse the supporting force in multiple directions when subjected to pressure, improving the structure's compressive strength and stability. This arrangement significantly enhances the strength of the battery box's floor structure 20, ensuring the long-term stable operation of the battery system.

[0064] Optionally, the upper plate 21 is made of aluminum alloy; and / or the middle plate 22 is made of titanium alloy; and / or the lower plate 23 is made of aluminum alloy, and the lower plate 23 seals the hollow space of the middle plate 22 .

[0065] The selection of these materials is based on the need to improve the overall mechanical properties of the battery box and reduce its weight. Aluminum alloy, due to its excellent thermal conductivity and light weight, was chosen as the manufacturing material for the upper plate 21 and lower plate 23. This effectively dissipates heat without significantly increasing the weight of the battery box. Titanium alloy, due to its high strength and corrosion resistance, was used to manufacture the middle plate 22, ensuring the strength and stability of the battery box's bottom plate structure 20. At the same time, the lightweight properties of titanium alloy also help to reduce the overall weight. This design ensures that the battery box maintains structural strength and heat dissipation performance while effectively controlling its weight, improving the overall performance and safety of the battery system while also reducing production costs.

[0066] In a specific embodiment of the present application, the bottom plate structure 20 adopts a lightweight skeleton-like topology optimization design, the bottom plate structure 20 adopts a layered composite structure, the upper plate body 21 is made of 6061 aluminum alloy material, and multiple positioning grooves 211 form a square honeycomb structure. The size of the positioning groove 211 is adapted to the external dimensions of the battery cell 40 to achieve fixture-free self-positioning of the battery cell 40; the middle plate body 22 is made of titanium alloy material, and an X-shaped first support beam 221 and a second support beam 222 are adopted, and then combined with multiple distributed branch beams 223 to achieve multi-level stress distribution and multi-level load transfer system, taking into account both lightweight and high strength; the lower plate body 23 is made of 6061 aluminum alloy material, and covers, protects and seals the upper plate body 21 and the middle plate body 22.

[0067] like Figure 1 and Figure 2 As shown, the battery box also includes an air inlet fan 50, which is connected to the air flow channel 11 and is used to drive the air flow into the air flow channel 11 and flow along the air flow channel 11; and / or, the battery box also includes an air outlet fan, and the box structure 10 also has an air outlet channel connected to the accommodating cavity 30, and the air outlet fan is connected to the air outlet channel and is used to drive the air flow from the air outlet channel to flow out of the accommodating cavity 30.

[0068] The design of the inlet fan 50 and the outlet fan meets the requirements of air circulation within the battery box and improves heat dissipation efficiency. The inlet fan 50 is responsible for introducing fresh air from the outside into the air flow channel 11, while the outlet fan is responsible for exhausting the hot air after heat exchange from the interior of the box structure 10. The rational layout of the fans and the design of the air flow channel 11 ensure smooth airflow within the box structure 10, improve heat exchange efficiency, and reduce the operating temperature of the battery cells 40. This design makes the battery box thermal management more efficient and the temperature control of the battery cells 40 more precise, improving the overall performance and safety of the battery system.

[0069] like Figure 2 As shown, under the condition that the battery box includes an air inlet fan 50 and an air outlet fan, the air flow channel 11 is arranged at the upper part of the box structure 10, the air inlet fan 50 is arranged at the inlet of the air flow channel 11, and the inlet is located at one end of the box structure 10; the air outlet channel is arranged at the bottom of the box structure 10, the air outlet fan is arranged at the outlet of the air outlet channel, and the outlet is located at the other end of the box structure 10.

[0070] The position design of the air inlet fan 50 and the air outlet fan meets the requirements of optimizing the airflow path and improving the heat dissipation efficiency; the air inlet fan 50 is located at the entrance of the air flow channel 11 at one end of the box structure 10, which can ensure that fresh air directly enters the air flow channel 11 and reduces the resistance before the air flow enters; the air outlet fan is located at the outlet of the air outlet channel at the other end of the box structure 10, which can effectively guide the hot air to be discharged from the inside of the box structure 10, avoiding the hot air from being retained inside the battery box and affecting the heat dissipation effect; the reasonable layout of the fan position ensures the smooth circulation of the airflow, improves the heat exchange efficiency, and reduces the operating temperature of the battery cell 40.

[0071] In addition, by designing that the air inlet fan 50 and the air outlet fan are located at both ends of the box structure 10, the air flow is discharged only after it has completely flowed through the box structure 10, avoiding the fresh air flow from the accommodating cavity 30 before completing the convection heat dissipation process, thereby ensuring high heat dissipation efficiency.

[0072] like Figure 1 As shown, the present application also provides a battery pack, which includes the above-mentioned battery box and a plurality of battery cells 40.

[0073] The battery pack proposed in this application provides a stable operating environment for multiple battery cells 40. It not only utilizes the battery box's airflow channels 11 and heat dissipation gaps 41 for efficient thermal management, but also provides stable physical support and protection with the battery box's bottom plate structure 20 and box structure 10.

[0074] Specifically, multiple battery cells 40 correspond one-to-one with multiple positioning grooves 211; the outer periphery of the battery cell 40 is coated with a thermally conductive metal layer, and at least a portion of the thermally conductive metal layer of the battery cell 40 is located in the heat dissipation gap 41, and the thermally conductive metal layer is used for heat exchange.

[0075] The coordinated design of the battery cell 40 and the positioning groove 211 is based on the need to improve the heat dissipation efficiency and ensure the stability of the battery cell 40. The provision of the thermally conductive metal layer not only improves the heat exchange efficiency between the battery cell 40 and the surrounding environment, but also acts as a protective layer for the battery cell 40 to a certain extent. When the battery cell 40 operates under extreme conditions and causes the thermally conductive metal layer to melt, the positioning groove 211 can collect the molten metal to prevent it from flowing into other key parts of the battery pack and causing short circuits or other faults. The above design significantly enhances the thermal management capability of the battery pack, and can effectively control the temperature of the battery cell 40 even under high-load working conditions, thereby improving the reliability and safety of the battery system.

[0076] Optionally, the periphery of the thermally conductive metal layer is covered with a packaging flexible film; the thermally conductive metal layer melts at a temperature higher than the melting temperature; the thermally conductive metal layer is fixed on the periphery of the battery core 40 at a temperature not higher than the melting temperature; wherein the leakage temperature is higher than the melting temperature; when the temperature of the thermally conductive metal layer is higher than the melting temperature and not higher than the leakage temperature, the interior of the packaging flexible film accommodates the thermally conductive metal layer in a molten state; when the temperature of the thermally conductive metal layer is higher than the leakage temperature, the thermally conductive metal layer in a molten state flows out of the packaging flexible film, and at this time, the positioning groove 211 accommodates the melted thermally conductive metal layer.

[0077] The combined use of the thermally conductive metal layer and the encapsulating flexible film meets the needs of improving the thermal management capabilities of the battery pack and ensuring system safety; the thermally conductive metal layer is fixed to the periphery of the battery cell 40 at normal operating temperature, thereby improving the heat exchange efficiency between the battery cell 40 and the surrounding environment; when the battery cell 40 operates under extreme conditions, causing the temperature of the thermally conductive metal layer to exceed its melting point, the encapsulating flexible film can temporarily accommodate the molten metal to prevent it from leaking immediately, giving the system a certain response time to take measures to avoid accidents; the above design enables the battery pack to effectively prevent leakage of the thermally conductive metal layer through the buffering effect of the encapsulating flexible film when facing sudden high temperature conditions, thereby improving the safety and reliability of the system.

[0078] In a specific embodiment of the present application, the thermally conductive metal layer adopts a high-gallium-based liquid metal material (for example, a high-gallium-based liquid metal material with a thickness of 0.1 mm and a thermal conductivity of 30 W / m·K), which can effectively take away the heat from the surface of the battery cell 40. The packaging flexible film adopts a PDMS flexible film with low contact thermal resistance, and a hot melt plug with a melting point of 65°C (i.e., corresponding to the leakage temperature) is provided at the bottom of the packaging flexible film. When the temperature is higher than 65°C (i.e., corresponding to the leakage temperature), the hot melt plug melts, and the thermally conductive metal layer in a molten state flows out of the packaging flexible film through the hot melt plug. At this time, the positioning groove 211 receives the melted thermally conductive metal layer to prevent the battery cell 40 from short-circuiting.

[0079] It should be noted that the PDMS (Polydimethylsiloxane) flexible film in the above embodiment is a polydimethylsiloxane flexible film, which is a high-performance silicone material. Due to its unique physical and chemical properties, it is widely used in the packaging, heat dissipation and protection of batteries and other electronic devices. The PDMS flexible film used in this application has the following characteristics: 1. High thermal stability: The PDMS flexible film can maintain its physical properties in a wide temperature range and can usually withstand temperatures from -60°C to 200°C, which enables it to work stably in the high temperature environment of the battery pack and will not fail due to temperature changes; 2. Good insulation: The PDMS flexible film is a good insulating material, which is very important in battery pack design because it can prevent short circuits between battery cells 40 or between battery cells 40 and other metal parts of the battery pack, thereby improving the overall safety of the battery pack; 3. Flexibility and elasticity: The PDMS flexible film has excellent flexibility and elasticity 4. Low contact thermal resistance: In the heat dissipation solution where liquid metal is coated on the surface of the battery cell 40, the low contact thermal resistance of the PDMS flexible film means that it can effectively promote heat exchange between the liquid metal and the surface of the battery cell 40, thereby improving heat dissipation efficiency. 5. Moisture permeable and airtight: The PDMS flexible film has the properties of moisture permeability and airtightness, which means that it can block oxygen and water vapor in the air, preventing oxidation and corrosion of the battery cell 40, while allowing volatile substances such as water vapor generated inside the battery to pass through, maintaining the humidity balance inside the battery. 6. Biocompatibility and non-toxicity: The PDMS flexible film is safe and harmless to the human body. This property is also very important in battery pack design, especially when considering battery pack recycling and environmental impact.

[0080] Therefore, the PDMS flexible film of the liquid metal heat dissipation layer applied to the surface of the encapsulated battery cell 40 can prevent the metal layer from leaking. At the same time, when the battery cell 40 is overheated, the hot melt plug on the PDMS film will open when a specific temperature is reached, allowing the liquid metal to flow into the preset collection structure (for example: into the positioning groove 211), thereby avoiding the risk of short circuit.

[0081] Now, a specific embodiment of the present application is described in detail as follows:

[0082] The surface of the battery cell 40 is coated with gallium-based liquid metal with high thermal conductivity, and is installed and fixed in conjunction with the multiple positioning grooves 211 arranged in a honeycomb pattern on the upper plate 21 of the battery pack; sufficient heat dissipation gaps are formed between the multiple battery cells 40 arranged in a matrix; the bottom plate structure 20 of the battery pack adopts a lightweight and high-strength three-layer composite structure (i.e., the upper plate 21, the middle plate 22 and the lower plate 23), and the positioning grooves 211 on the upper plate 21 have the functions of positioning the battery cell 40 and collecting the liquid metal coated on the surface of the battery cell 40; the middle plate 22 is made of titanium alloy material, and through the mechanical design of the first support beam 221, the second support beam 222 and the multiple branch beams 223, it has lightweight and high-strength load-bearing properties. Function; The lower plate 23 has a sealing function to protect the upper plate 21 and the middle plate 22; The leaf-vein-shaped airflow channel 11 is formed by casting in the box structure 10 of the battery pack, and the air inlet fan 50 blows the cooling air evenly to the surface of the battery cell 40 and the heat dissipation gap 41 (including the battery cell 40 located in the middle part of the accommodating cavity 30) through multiple air outlets 111, and the air outlet fan sucks the hot air out of the battery pack to ensure that the temperature of the entire pack is low and the temperature difference between the battery cells 40 is small, thereby making the overall heat dissipation effect of the battery pack good, the temperature difference of the battery cells 40 is small, and the performance and service life of the battery pack can be effectively guaranteed; The overall design of the battery pack proposed in this application takes into account both lightweight and high strength, so that the energy efficiency of the battery pack is relatively high.

[0083] The present application adopts a heat dissipation method that combines the coating of gallium-based liquid metal with high thermal conductivity on the surface of the battery cell 40 and the casting of air flow channels 11 in the box structure 10 of the battery pack, which can timely and efficiently remove the heat generated by the battery cell 40 during the charging and discharging process. The specific design of the air flow channel 11 makes the air volume of the air duct evenly distributed, thereby making it possible for multiple battery cells 40 to dissipate heat efficiently, and the temperature difference between the battery cells 40 is small, which effectively improves product performance and extends product life; the bottom plate structure in the present application adopts a lightweight and high-strength three-layer design, which is easy to weld and fix into shape, and the upper plate body 21 and the lower plate body 23 are made of high-strength aluminum alloy to achieve mechanical properties and weight. For optimal balance, the middle plate 22 is made of titanium alloy material, and adopts an X-shaped distributed first support beam 221 and a second support beam 222, combined with a plurality of distributed branch beams 223 to achieve multi-level stress distribution; compared with the traditional liquid-cooled base plate that requires mold opening and processing, the base plate structure 20 of this application can adopt welding + 3D printing technology, which is convenient for the processing and forming of the base plate structure 20 and has a greater cost advantage; in addition, the arrangement of the battery cells 40 of the battery pack proposed in this application is also different from that of ordinary battery packs. There is a gap of about 4 mm between two adjacent battery cells 40 in the battery pack of this application to form a heat dissipation gap 41.

[0084] In summary, the present application provides a battery box and a battery pack. The present application provides a battery box and a battery pack. The bottom plate structure 20 is provided with a plurality of positioning grooves 211 arranged at intervals on the side facing the accommodating cavity 30, so that each positioning groove 211 can be limited and matched with at least one battery cell 40, thereby realizing fixture-free fixation and reliable load-bearing of the battery cell 40; by arranging the battery cells 40 located in different positioning grooves 211 at intervals, a heat dissipation gap 41 is formed, so that the gas flowing out of the air flow channel 11 can flow through the heat dissipation gap 41 for heat exchange, thereby improving the heat dissipation uniformity of the multiple battery cells 40; compared with the existing air-cooled heat dissipation For the thermal battery pack, the temperature difference between the battery cells 40 in this application is small, which will not destroy the consistency of the battery cells 40, and can quickly discharge heat to the outside of the battery box, effectively dissipating the heat efficiently, thereby ensuring the safety and service life of the battery pack; compared with the existing battery pack using liquid cooling, the battery box of this application has a simple structure, is easy to process and form, and is low in price. The overall energy density of the battery pack can be subsequently improved through the lightweight design of the bottom plate structure 20; the battery box proposed in this application has a reasonable heat dissipation design, which can meet the heat dissipation requirements of the battery cells 40, has a simple structure and low cost, and is suitable for promotion and use.

[0085] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0086] Unless otherwise specifically stated, the relative arrangement of the parts and steps, numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present application. At the same time, it should be understood that, for ease of description, the sizes of the various parts shown in the drawings are not drawn according to actual proportional relationships. The techniques, methods and equipment known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, the techniques, methods and equipment should be considered as part of the authorization specification. In all examples shown and discussed here, any specific values should be interpreted as being merely exemplary and not as limitations. Therefore, other examples of the exemplary embodiments may have different values. It should be noted that similar numbers and letters represent similar items in the following figures, and therefore, once an item is defined in one figure, it does not need to be further discussed in subsequent figures.

[0087] In the description of this application, it should be understood that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "horizontal, vertical, vertical, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of this application; the directional words "inside and outside" refer to the inside and outside relative to the outline of each component itself.

[0088] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used herein to describe the spatial positional relationship of a device or feature to other devices or features as shown in the figures. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figures. For example, if the device in the drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0089] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of this application.

[0090] The above description is merely a preferred embodiment of the present application and is not intended to limit the present application. Various modifications and variations are possible for those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. A battery box, characterized in that: include: A box structure (10) and a bottom plate structure (20); a receiving cavity (30) is formed between the bottom plate structure (20) and the box structure (10), and the receiving cavity (30) is used to receive a plurality of battery cells (40); an air flow channel (11) is provided inside the box structure (10) and is in communication with the receiving cavity (30); wherein the plurality of battery cells (40) are arranged at intervals to form a heat dissipation gap (41); and gas flowing out of the air flow channel (11) flows through the heat dissipation gap (41) to perform heat exchange.

2. The battery box according to claim 1, characterized in that: The air flow channel (11) is arranged at the upper part of the box structure (10), and the air flow channel (11) has a plurality of air outlets (111) for discharging air, and the air outlets (111) are communicated with the accommodating cavity (30), and at least a portion of the plurality of air outlets (111) are arranged toward the battery cell (40) or the heat dissipation gap (41); wherein, when the box structure (10) and the plurality of battery cells (40) are projected onto the same horizontal plane from top to bottom, the projections of at least a portion of the plurality of air outlets (111) at least partially overlap with the projections of the plurality of heat dissipation gaps (41).

3. The battery box according to claim 2, characterized in that: The bottom plate structure (20) is fixedly connected to the bottom of the box structure (10); a side of the bottom plate structure (20) facing the accommodating cavity (30) has a plurality of positioning grooves (211) arranged at intervals, each positioning groove (211) being limitedly matched with at least one of the battery cells (40) to fix and support the battery cell (40); the battery cells (40) located in different positioning grooves (211) are arranged at intervals to form the heat dissipation gap (41); The bottom plate structure (20) has a plurality of positioning protrusions (212) on one side facing the accommodating cavity (30), and the bottom plate structure (20) has a width direction and a length direction that are horizontal and perpendicular to each other; the plurality of positioning protrusions (212) are arranged in rows and columns along the width direction, and are arranged in columns and rows along the length direction, so as to stagger and form a plurality of positioning grooves (211) arranged in rows and columns; two adjacent positioning grooves (211) in the same row or column are not connected; the positioning protrusions (212) located in the circumference of one positioning groove (211) are used to limit the battery cell (40) located in the positioning groove (211).

4. The battery box according to claim 3, characterized in that: The air flow channel (11) includes a main air channel (112) and a plurality of branch air channels (113), wherein the main air channel (112) is connected to the outside of the box structure (10); the extension direction of the branch air channel (113) is arranged in parallel with the length direction, and the plurality of branch air channels (113) are respectively connected to the main air channel (112) and are arranged at intervals along the width direction; a portion of the plurality of air outlets (111) is located on at least a portion of the plurality of branch air channels (113), and the air outlet (111) is a first air outlet, and the extension direction of the first air outlet is arranged in parallel with the length direction; wherein, the box structure (10) and the plurality of battery cells (40) are projected onto the same horizontal plane from top to bottom, and the projection of the first air outlet at least partially overlaps with the projection of the plurality of positioning protrusions (212).

5. The battery box according to claim 4, characterized in that: The air flow channel (11) further comprises a plurality of connecting air channels (114), the extending direction of the connecting air channels (114) being arranged in parallel with the width direction, and the two ends of the connecting air channels (114) being respectively connected with the two adjacent branch air channels (113); the plurality of connecting air channels (114) located between the same two adjacent branch air channels (113) being arranged at intervals along the length direction; a portion of the plurality of air outlets (111) being located on at least a portion of the connecting air channels (114), the air outlet (111) being a second air outlet, the extending direction of the second air outlet being arranged in parallel with the width direction; wherein, the box structure (10) and the plurality of battery cells (40) are projected onto the same horizontal plane from top to bottom, and the projection of the second air outlet at least partially overlaps with the projection of the plurality of positioning protrusions (212).

6. The battery box according to claim 1, characterized in that: The bottom plate structure (20) has a plurality of positioning grooves (211) arranged at intervals on a side facing the accommodating cavity (30), and the plurality of positioning grooves (211) correspond to the plurality of battery cells (40) one by one to fix and support the battery cells (40); the battery cells (40) located in different positioning grooves (211) are arranged at intervals to form the heat dissipation gap (41); the outer periphery of the battery cell (40) is coated with a heat-conducting metal layer, and the positioning groove (211) is also used to receive the melted heat-conducting metal layer on the battery cell (40) located in the positioning groove (211); and / or the width of the heat dissipation gap (41) is not less than 2 mm and not more than 6 mm.

7. The battery box according to claim 1, characterized in that: The bottom plate structure (20) includes an upper plate body (21), a middle plate body (22) and a lower plate body (23); the middle plate body (22) is fixedly arranged at the lower part of the upper plate body (21); the middle plate body (22) is hollowed out and is used to support and carry the upper plate body (21); the lower plate body (23) is arranged at the lower part of the middle plate body (22) and is used to protect and carry the upper plate body (21) and the middle plate body (22).

8. The battery box according to claim 7, characterized in that: The middle plate body (22) comprises a first support beam (221), a second support beam (222) and a plurality of branch beams (223); the middle portion of the first support beam (221) is fixedly connected to the middle portion of the second support beam (222), and the extension direction of the first support beam (221) and the extension direction of the second support beam (222) form an angle to form an X-shaped cross structure; the X-shaped cross structure has four hollow spaces, and at least one branch beam (223) is provided in each of the hollow spaces; the two ends of the branch beam (223) are fixedly connected to the first support beam (221) and the second support beam (222), respectively.

9. The battery box according to claim 8, characterized in that: A plurality of branch beams (223) are provided in each of the hollow spaces; the plurality of branch beams (223) located in the same hollow space are equidistant and arranged in parallel; wherein the extension direction of the first support beam (221) is not perpendicular to the extension direction of the second support beam (222); the box structure (10) has a width direction and a length direction that are horizontal and perpendicular to each other; the extension direction of the first support beam (221) and the extension direction of the second support beam (222) respectively have an angle with the length direction, and the extension direction of the branch beam (223) is parallel to the width direction.

10. The battery box according to claim 7, characterized in that: The upper plate (21) is made of an aluminum alloy material; and / or the middle plate (22) is made of a titanium alloy material; and / or the lower plate (23) is made of an aluminum alloy material, and the lower plate (23) seals the hollow space of the middle plate (22).

11. The battery box according to claim 1, characterized in that: The battery box further includes an air intake fan (50), the air intake fan (50) being in communication with the air flow channel (11) and configured to drive air flow into the air flow channel (11) and flow along the air flow channel (11); And / or, the battery box further comprises an air outlet fan, the box structure (10) further comprises an air outlet channel connected to the accommodating cavity (30), and the air outlet fan is connected to the air outlet channel and is used to drive airflow from the air outlet channel out of the accommodating cavity (30).

12. The battery box according to claim 11, characterized in that: Under the condition that the battery box includes the air inlet fan (50) and the air outlet fan, the air flow channel (11) is arranged at the upper part of the box structure (10), the air inlet fan (50) is arranged at the inlet of the air flow channel (11), and the inlet is located at one end of the box structure (10); the air outlet channel is arranged at the bottom of the box structure (10), the air outlet fan is arranged at the outlet of the air outlet channel, and the outlet is located at the other end of the box structure (10).

13. A battery pack, characterized in that: The battery pack comprises the battery box according to any one of claims 1 to 12, and further comprises a plurality of battery cells (40).

14. The battery pack according to claim 13, wherein: The bottom plate structure (20) has a plurality of positioning grooves (211) arranged at intervals on one side facing the accommodating cavity (30). The plurality of battery cells (40) are matched with the plurality of positioning grooves (211) in a one-to-one correspondence; the outer periphery of the battery cell (40) is coated with a heat-conducting metal layer, and the heat-conducting metal layer of at least a portion of the battery cell (40) is located in the heat dissipation gap (41), and the heat-conducting metal layer is used for heat exchange.

15. The battery pack according to claim 14, characterized in that: The outer periphery of the heat-conducting metal layer is covered with a packaging flexible film; the heat-conducting metal layer melts at a temperature higher than the melting temperature; the heat-conducting metal layer is fixed on the outer periphery of the battery core (40) at a temperature not higher than the melting temperature; wherein the leakage temperature is higher than the melting temperature; when the temperature of the heat-conducting metal layer is higher than the melting temperature and not higher than the leakage temperature, the heat-conducting metal layer in a molten state is received inside the packaging flexible film; when the temperature of the heat-conducting metal layer is higher than the leakage temperature, the heat-conducting metal layer in a molten state flows out of the packaging flexible film, and at this time, the positioning groove (211) receives the melted heat-conducting metal layer.

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