Battery pack and electric device

Abstract

The application provides a battery pack and an electric device, the battery pack comprising at least a battery group and a heat exchange plate, the battery group comprising at least one battery column, the battery column comprising a plurality of battery monomers arranged along a first direction; the bottom surface of the battery monomer is provided with an explosion-proof valve; the heat exchange plate is arranged at the bottom of the battery group and exchanges heat with the battery monomer, the heat exchange plate is provided with at least one flow channel, the flow channel extends along the first direction and internally circulates heat exchange liquid to exchange heat with the battery monomer; wherein the flow channel has a first section and a second section, the projection of the explosion-proof valve along a second direction is completely located in the projection of the first section along the second direction, the second direction is perpendicular to the first direction and perpendicular to the height direction of the battery monomer; the maximum width of the first section along the second direction is A mm, the maximum width of the second section along the second direction is B mm, and A / B satisfies 0.1<=A / B<=0.3.

Description

Technical Field

[0001] This application relates to the field of batteries, specifically to a battery pack and an electrical device. Background Technology

[0002] During use, batteries may experience thermal runaway due to overcharging, short circuits, or high-temperature environments. When a battery experiences thermal runaway, it generates a large amount of high-temperature, high-pressure gas. The accumulation of this gas inside the battery can lead to explosions. Therefore, battery casings are often equipped with explosion-proof valves. When the internal pressure of the battery reaches the valve's pressure relief capacity, the valve promptly connects to the outside environment and releases pressure.

[0003] To prevent the high-temperature, high-pressure gas ejected from the explosion-proof valve from directly impacting electrical components and causing problems such as short circuits and insulation failure, batteries with explosion-proof valves located at the bottom have been developed. Because the explosion-proof valve is located at the bottom, the ejected fluids can be discharged downwards, avoiding direct contact with electrical components, thus achieving thermoelectric separation and improving the overall safety of the battery pack.

[0004] In existing battery packs, because the explosion-proof valve occupies the bottom space of the battery cell, and the heat exchange plate is also located at the bottom of the battery pack, it is easy to affect the heat exchange between the battery cell and the heat exchange plate. The battery cell cannot operate within the appropriate temperature range, which affects the performance of the battery pack. Utility Model Content

[0005] In view of this, the present application aims to provide a battery pack and electrical equipment to solve the technical problem that in existing battery packs, when the explosion-proof valve occupies the bottom space of the battery cell and the heat exchange plate is also set at the bottom of the battery pack, the heat exchange between the battery cell and the heat exchange plate is easily affected, the battery cell cannot work within the appropriate temperature range, and the working performance of the battery pack is affected.

[0006] The first aspect of this application provides a battery pack, comprising: A battery pack, comprising at least two battery cells, wherein at least two battery cells arranged along a first direction form a battery array; an explosion-proof valve is provided on the bottom surface of each battery cell; A heat exchange plate is disposed at the bottom of the battery pack and is configured to exchange heat with the individual battery cells. The heat exchange plate has at least one flow channel extending along a first direction and through which heat exchange liquid flows to exchange heat with the individual battery cells. The flow channel has a first section and a second section. The projection of the explosion-proof valve along the second direction is completely within the projection of the first section along the second direction, and the projection of the explosion-proof valve along the second direction is completely outside the projection of the second section along the second direction. The second direction is perpendicular to the first direction and perpendicular to the height direction of the battery cell. The maximum width of the first segment in the second direction is A mm, and the maximum width of the second segment in the second direction is B mm, where A / B satisfies 0.1≤A / B≤0.3.

[0007] Another aspect of this application provides an electrical device including the aforementioned battery pack.

[0008] In the battery pack of this application embodiment, when the maximum width A mm of the first section in the second direction and the maximum width B mm of the second section in the second direction satisfy 0.1≤A / B≤0.3, not only can the heat exchange efficiency between the first section and the bottom surface of the battery cell be guaranteed, but the dead zone ratio in the second section can also be reduced, thereby improving the heat exchange efficiency between the second section and the bottom surface of the battery cell. Furthermore, the total heat exchange area between the flow channel and the battery cell can be effectively guaranteed, thereby ensuring the overall heat exchange efficiency between the flow channel and the battery cell. Attached Figure Description

[0009] It should be understood that the following figures only show some embodiments of this application and should not be regarded as a limitation on the scope.

[0010] It should be understood that the same or similar reference numerals are used in the accompanying drawings to denote the same or similar elements.

[0011] It should be understood that the accompanying drawings are only schematic, and the dimensions and scales of the elements in the drawings are not necessarily precise.

[0012] Figure 1 This is a perspective view of the battery pack according to an embodiment of this application.

[0013] Figure 2 This is another cross-sectional schematic diagram of the battery pack according to an embodiment of this application.

[0014] Figure 3 This is another perspective view of the battery pack according to an embodiment of this application.

[0015] Figure 4 This is a partial bottom view of the battery pack according to an embodiment of this application.

[0016] Figure 5 This is a partial bottom view of the battery pack according to an embodiment of this application.

[0017] Attached image labels: 10. Box body; 11. Base plate; 12. Frame; 20. Battery pack; 2. Battery cell; 21. Housing; 22. Cover plate; 23. Explosion-proof valve; 28. Battery row; 30. Heat exchange plate; 32. Flow channel; 321. First section; 322. Second section; 323. Blocking area.

[0018] X - First direction; Y - Second direction; Z - Height direction. Detailed Implementation

[0019] Numerous specific details are set forth below to provide an understanding of the structure, function, and use of the embodiments described and illustrated in the specification and figures. It is to be understood that the embodiments described and illustrated herein are non-limiting examples, and thus it will be appreciated that the particular structural and functional details disclosed herein are representative and exemplary. Variations and changes may be made to these embodiments without departing from the scope of the claims.

[0020] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0021] like Figures 1 to 5 As shown in the figure, this application embodiment provides a battery pack, including a battery pack 20 and a heat exchange plate 30. The battery pack 20 includes at least one battery column 28, and the battery column 28 includes at least two battery cells 2, and the at least two battery cells 2 arranged along a first direction form a battery column 28.

[0022] It is understood that the battery pack in this embodiment is a complete functional unit that can directly output electrical energy, consisting of a battery pack 20, a battery management system, a thermal management system, an electrical connection system, structural components, and protective components, all housed within a housing 10 and sealed by a cover plate 22. The battery pack 20 is formed by multiple battery cells 2 connected in series and / or parallel. The electrical connection system includes high-voltage connectors, low-voltage connectors, and wiring harnesses. The structural components include a housing and a support frame. The battery pack in this embodiment, as a rechargeable battery, can be a power source for new energy vehicles. The battery pack in this embodiment may also include an isolation plate, with both the battery cells 2 and the isolation plate located within the housing 10. The isolation plate is located on the side of the battery cell 2 away from the bottom plate 11 of the housing 10, separating the battery cell 2 from other components located above it.

[0023] The housing 10 in this embodiment can be a closed or semi-closed structure made of materials such as metal or plastic. It serves as the physical carrier of the battery pack 20, and its design and manufacturing must meet the safety, reliability, and functionality requirements of the battery pack under different usage scenarios. The housing 10 provides installation space for the battery pack 20, battery management system, cooling system, electrical connection components, etc., and through reasonable structural design, fixes these components inside the housing 10 to ensure that they maintain a relatively stable position during battery pack operation, avoiding damage to components or loosening of connections due to vibration, impact, or other factors.

[0024] The housing 10 may include a lower housing 10 and an upper housing 10. The lower housing 10 includes a base plate 11 and a frame 12 connected to and surrounding the base plate 11. The upper housing 10 is connected to the frame 12 and has a cover plate 22 opposite to the base plate 11. The upper housing 10 and the lower housing 10 together enclose a receiving cavity. The frame 12 and the base plate 11 can be integrally formed or formed by separate processing and then fixed connection. Specifically, the frame 12 and the base plate 11 are fixedly connected by welding, riveting, screwing, etc. When the housing 10 is a cube, the frame 12 of the lower housing 10 generally has four side plates, which surround the periphery of the base plate 11. In other embodiments, the shape of the housing 10 can also be a cylinder or other shapes. The frame 12 mainly serves to support, protect, and connect. The frame 12 can be formed by splicing multiple beams together. The frame 12 can be rectangular, circular, polygonal, etc., and is not limited here. The beam of frame 12 can be a solid structure or contain cavities. The base plate 11 is the main load-bearing component of the battery pack, used to support and fix the battery pack 20, battery management system, cooling system and other components inside the battery pack. The casing 10 can be cast from materials such as steel and aluminum alloy, or lightweight materials such as glass fiber reinforced composite material and carbon fiber reinforced composite material.

[0025] Multiple battery cells 2 with similar capacity and internal resistance are connected in series or parallel to form a battery pack 20. Each battery cell 2 can store chemical energy and controllably convert it into electrical energy. In a recyclable battery, the active materials can be reactivated by charging after discharge for continued use. Each battery cell 2 includes at least a housing 21 and a cover plate 22 fixedly connected to each other, as well as a cell and electrolyte. The housing 21 and cover plate 22 together house the cell and electrolyte. The cover plate 22 may have at least one positive electrode post and at least one negative electrode post for electrical connection to the outside. The cell includes one or more electrode assemblies, which are formed by stacking or winding positive electrode plates, negative electrode plates, and a separator. The separator is located between adjacent positive and negative electrode plates to insulate them. At least one end of the electrode assembly has a tab, and one end of an adapter plate is electrically connected to the tab, while the other end is electrically connected to the post. It is understood that the battery cell 2 in this application embodiment can be a lithium-ion battery, sodium-ion battery, sodium-lithium-ion battery, lithium metal battery, sodium metal battery, lithium-sulfur battery, magnesium-ion battery, nickel-metal hydride battery, nickel-cadmium battery, lead-acid battery, etc., and is not limited herein.

[0026] An explosion-proof valve 23 refers to a component or part that can be actuated to release internal pressure or temperature when the internal pressure or temperature of a single battery cell 2 reaches a predetermined threshold. During battery use, the explosion-proof valve 23 is mainly used to allow gas to escape from the battery and reduce internal pressure in the event of thermal runaway or other situations, preventing excessive pressure buildup that could cause deformation or explosion. The material of the explosion-proof valve 23 is not limited, including but not limited to aluminum, steel, and alloys. The shape of the explosion-proof valve 23 is not limited, such as square, oblong, elliptical, racetrack-shaped, etc. The type of explosion-proof valve 23 is not limited, such as a notched explosion-proof valve 23, which can be formed by stamping or laser etching.

[0027] Since an explosion-proof valve 23 is installed on the bottom surface of the battery cell 2, when the internal pressure of the battery reaches the pressure relief strength of the explosion-proof valve 23, the explosion-proof valve 23 will connect with the outside and release pressure in time; the ejected material and other fluids from the explosion-proof valve 23 will be discharged downwards to avoid direct contact with the electrical components above the battery cell 2, so as to achieve thermal and electrical separation and improve the overall safety of the battery pack.

[0028] The heat exchange plate 30 is disposed at the bottom of the battery pack 20 and is configured to exchange heat with the battery cell 2; specifically, the heat exchange plate 30 is attached to the bottom surface of the battery cell 2 and can heat and / or cool the battery cell 2 as needed.

[0029] The heat exchange plate 30 is a component for regulating battery temperature. The heat exchange plate 30 has internal heat exchange channels for circulating heat exchange media. These media can be gases such as air, liquids such as water, alcohols, refrigerants, and oils, or solids such as thermally conductive adhesives and solder paste. The heat exchange channels have inlets and outlets for the heat exchange media. The media enters the heat exchange channel through the inlet, exchanges heat with the battery cell 2, and then exits through the outlet, thus achieving heat exchange with the battery cell 2. The heat exchange plate 30 can be made of a material with high thermal conductivity, such as copper; alternatively, it can have heat pipes that can rapidly transfer heat through convection; or it can have channels that connect to heating or cooling devices, with liquid media flowing within these channels for efficient heat exchange. The heat exchange plate 30 may include a heating element and an electrical connector. The heating element can be a heating wire, a heating film, or a heating plate; this application does not impose any limitations on these components. The heat exchange plate 30 can be made of metal materials, such as aluminum alloy or magnesium alloy; or it can be made of plastic.

[0030] like Figures 3 to 4 As shown, the heat exchange plate 30 has at least one flow channel 32 extending along a first direction and through which a heat exchange liquid flows to exchange heat with the battery cells 2. Therefore, the heat exchange plate 30 can utilize the heat exchange liquid flowing within the flow channel 32 for heat exchange, ensuring that the battery cells 2 operate within their optimal operating range. Since the flow channel 32 extends along the first direction, the heat exchange liquid within the same flow channel 32 can simultaneously exchange heat with multiple battery cells 2 arranged along the first direction, thereby ensuring the heat exchange efficiency between the heat exchange plate 30 and the battery cells 2 of the battery pack 20. It is understood that the heat exchange liquid can be water, oil, an aqueous solution of ethylene glycol, etc., and is not limited thereto.

[0031] Among them, such as Figure 4 As shown, the flow channel 32 has a first section 321 and a second section 322. The projection of the explosion-proof valve 23 along the second direction is completely within the projection of the first section 321 along the second direction, and the projection of the explosion-proof valve 23 along the second direction is completely outside the projection of the second section 322 along the second direction. The second direction is perpendicular to the first direction and perpendicular to the height direction of the battery cell 2. That is, the first section 321 completely covers the area where the explosion-proof valve 23 of the battery cell 2 is located in the extension direction of the flow channel 32, and the second section does not correspond to the area where the explosion-proof valve 23 of the battery cell 2 is located in the extension direction of the flow channel 32.

[0032] Understandably, since the first section 321 completely covers the area where the explosion-proof valve 23 of the battery cell 2 is located in the extension direction of the flow channel 32, the explosion-proof valve 23 needs to occupy some space. Therefore, the width of the first section 321 in the second direction needs to be reduced to leave room for the explosion-proof valve 23. Compared with the first section 321, the width of the second section 322 in the second direction can be set to be larger, thereby increasing the heat exchange area between the flow channel 32 and the battery cell 2 and improving the heat exchange efficiency between the flow channel 32 and the battery cell 2.

[0033] like Figure 1 and Figure 2 As shown, the battery pack in this embodiment may further include a housing 10, which forms a receiving cavity for placing the battery pack 20. The housing 10 includes a bottom plate 11 and a frame 12, and a heat exchange plate 30 is disposed above the bottom plate 11.

[0034] Specifically, such as Figure 4 As shown, in the battery pack of this application embodiment, the maximum width of the first segment 321 in the second direction is A mm, the maximum width of the second segment 322 in the second direction is B mm, and A / B satisfies 0.1≤A / B≤0.3.

[0035] When the ratio A / B of the maximum width A mm of the first section 321 in the second direction and the maximum width B mm of the second section 322 in the second direction is less than 0.1, the width of the first section 321 is too small. This not only easily affects the heat exchange efficiency between the first section 321 and the bottom surface of the battery cell 2, but also, when the heat exchange liquid flows from the first section 321 to the second section 322, in the second direction, only the heat exchange liquid in the vicinity of the line connecting the inlet and outlet of the second section 322 flows relatively quickly. However, at the edge of the second section 322, because it is far from the inlet or outlet of the second section 322, the flow rate of the liquid is extremely low, making it difficult to participate in the exchange of the mainstream, thus forming a dead zone. The temperature of the heat exchange liquid in the dead zone tends to be the same as the temperature of the bottom surface of the battery cell 2, and heat easily accumulates in the dead zone, resulting in extremely low heat exchange efficiency.

[0036] When the ratio A / B of the maximum width A mm of the first section 321 in the second direction and the maximum width B mm of the second section 322 in the second direction is greater than 0.3, the width of the first section 321 is too large, and the width of the second section 322 will be restricted. This will result in the total heat exchange area between the flow channel 32 and the battery cell 2 being restricted, and will also affect the heat exchange efficiency between the flow channel 32 and the battery cell 2.

[0037] Therefore, when the maximum width A mm of the first section 321 in the second direction and the maximum width B mm of the second section 322 in the second direction satisfy 0.1 ≤ A / B ≤ 0.3, not only can the heat transfer efficiency between the first section 321 and the bottom surface of the battery cell 2 be guaranteed, but the dead zone ratio in the second section 322 can also be reduced, thereby improving the heat transfer efficiency between the second section 322 and the bottom surface of the battery cell 2. Furthermore, the total heat transfer area between the flow channel 32 and the battery cell 2 can be effectively guaranteed, thus ensuring the overall heat transfer efficiency between the flow channel 32 and the battery cell 2. In specific embodiments, the ratio of A / B can be 0.1, 0.12, 0.2, 0.25, 0.3, etc., which will not be elaborated further here.

[0038] Specifically, in one embodiment of this application, the maximum width A mm of the first segment 321 in the second direction satisfies 10 mm ≤ A mm ≤ 80 mm. When the maximum width A mm of the first segment 321 in the second direction is less than 10 mm, the width of the first segment 321 is too small, which can easily affect the heat exchange efficiency between the first segment 321 and the bottom surface of the battery cell 2, and also increase the flow resistance of the liquid flowing through the first segment 321, thereby reducing the flow velocity of the heat exchange liquid in the flow channel 32 and affecting the heat exchange efficiency. When the maximum width A mm of the first segment 321 in the second direction is greater than 80 mm, the width of the first segment 321 is too large, and the distance between the first segment 321 and the explosion-proof valve 23 is too close. When any battery cell 2's explosion-proof valve 23 sprays fluid downwards, the side wall of the flow channel 32 is prone to breakage, heat exchange liquid leakage, etc., affecting the continued normal operation of other battery cells 2.

[0039] Therefore, when the maximum width A mm of the first section 321 in the second direction satisfies 10 mm ≤ A mm ≤ 80 mm, it not only ensures the heat exchange efficiency between the first section 321 and the bottom surface of the battery cell 2, and reduces the flow resistance of the liquid flowing through the first section 321 to increase the flow velocity of the heat exchange liquid in the flow channel 32, thus affecting the heat exchange efficiency, it also avoids situations such as the side wall of the flow channel 32 breaking and the heat exchange liquid leaking when the explosion-proof valve 23 sprays fluid downwards, ensuring that other battery cells 2 continue to work normally and improving the working safety of the battery pack in this embodiment. In specific embodiments, the value of the maximum width A mm of the first section 321 in the second direction can be 10 mm, 30 mm, 50 mm, 60 mm, 80 mm, etc., which will not be elaborated here.

[0040] like Figure 4As shown in one embodiment of this application, the maximum width Bmm of the second segment 322 in the second direction satisfies 50mm ≤ Bmm ≤ 100mm. When the maximum width Bmm of the second segment 322 in the second direction is less than 50mm, the width of the second segment 322 is too small, which can easily affect the heat exchange efficiency between the second segment 322 and the bottom surface of the battery cell 2. When the maximum width Bmm of the second segment 322 in the second direction is greater than 100mm, a large dead zone is easily formed at the edge of the second segment 322. The heat of the heat exchange liquid in the dead zone tends to accumulate in the dead zone, which can negatively impact the heat exchange efficiency between the second segment 322 and the bottom surface of the battery cell 2. Therefore, when the maximum width Bmm of the second segment 322 in the second direction satisfies 50mm ≤ Bmm ≤ 100mm, not only can the heat exchange area between the first segment 321 and the bottom surface of the battery cell 2 be guaranteed, but the dead zone formed at the edge of the second segment can also be reduced, thus improving the heat exchange efficiency between the second segment 322 and the bottom surface of the battery cell 2 from two aspects. The maximum width B mm of the second section 322 in the second direction can be 50mm, 60mm, 80mm, 90mm, 100mm, etc., which will not be elaborated here.

[0041] Furthermore, such as Figure 4 As shown, in one embodiment of this application, a flow guide is provided in the second section 322. The flow guide is configured to allow the heat exchange liquid flowing into the second section 322 to flow to the two end edge regions of the second section 322 in the second direction, and / or to allow the heat exchange liquid in the two end edge regions of the second section 322 in the second direction to flow out of the second section 322.

[0042] It is understood that a flow guide is provided in the second section 322. The flow guide can cause the heat exchange liquid flowing into the second section 322 to flow to the two edge regions of the second section 322 in the second direction, or can cause the heat exchange liquid in the two edge regions of the second section 322 in the second direction to flow out of the second section 322, or can have both of the above functions at the same time.

[0043] Since the guide can allow the heat exchange liquid flowing into the second section 322 to flow to the two edge regions of the second section 322 in the second direction, or allow the heat exchange liquid in the two edge regions of the second section 322 in the second direction to flow out of the second section 322, the dead zone formed in the second section 322 can be effectively reduced and the heat exchange efficiency between the second section 322 and the bottom surface of the battery cell 2 can be improved without significantly affecting the heat exchange area between the second section 322 and the bottom surface of the battery cell 2.

[0044] In one embodiment of this application, the flow guide includes a flow guide plate configured to form an angle with the first direction, so that the heat exchange liquid moves along the flow guide plate. That is, during the operation of the battery pack in this embodiment, the heat exchange liquid moves along the flow channel 32. When it encounters the flow guide plate forming an angle with the first direction, it can move along the flow guide plate, thereby flowing to the two end edge regions of the second section 322 in the second direction, or the heat exchange liquid in the two end edge regions of the second section 322 in the second direction flows out of the second section 322 along the flow guide plate. This allows the heat exchange liquid in the two end edge regions of the second section 322 in the second direction to fully participate in the circulation flow, preventing the formation of dead zones, thereby improving the heat exchange efficiency between the second section 322 and the bottom surface of the battery cell 2.

[0045] like Figure 4 As shown, in one embodiment of this application, the flow guide includes a blocking area 323, which together with the outer edge of the flow channel 32 forms the flow channel 32; the projection of the blocking area 323 in the first direction at least partially coincides with the projection of at least one of the inlet and outlet of the second segment 322 in the first direction.

[0046] By setting a blocking region 323 inside the flow channel 32, since the projection of the blocking region 323 in the first direction at least partially coincides with the projection of at least one of the inlet and outlet of the second section 322 in the first direction, the blocking region 323 can prevent the heat exchange liquid in the flow channel 32 from passing directly from the inlet to the outlet, so that the heat exchange liquid moves around the blocking region 323. Therefore, during the movement of the heat exchange liquid along the flow channel 32, it can be guided by the blocking region 323, thereby flowing to the two end edge regions of the second section 322 in the second direction, or the heat exchange liquid in the two end edge regions of the second section 322 in the second direction can flow out of the second section 322 under the guiding effect of the blocking region 323. This allows the heat exchange liquid in the two end edge regions of the second section 322 in the second direction to fully participate in the circulation flow, preventing the formation of dead zones, thereby improving the heat exchange efficiency between the second section 322 and the bottom surface of the battery cell 2.

[0047] Furthermore, such as Figure 4As shown, the projected area of ​​the blocking region 323 along the height direction accounts for 20% to 50% of the area of ​​the second section 322. When the projected area of ​​the blocking region 323 along the height direction accounts for less than 20% of the area of ​​the second section 322, the flow guiding effect of the blocking region 323 is poor, and some dead zones are still formed within the second section 322. It is understood that the heat exchange fluid is only provided in the portion of the second section 322 excluding the blocking region 323. Therefore, when the projected area of ​​the blocking region 323 along the height direction accounts for more than 50% of the area of ​​the second section 322, the area of ​​the portion of the second section 322 containing the heat exchange fluid is small, reducing the heat exchange efficiency between the second section 322 and the bottom surface of the battery cell 2.

[0048] Therefore, when the projected area of ​​the blocking region 323 along the height direction accounts for 20% to 50% of the area of ​​the second section 322, the flow guiding effect of the blocking region 323 can be guaranteed, the formation of dead zones in the second section 322 can be minimized, and the area of ​​the second section 322 containing heat exchange liquid can be effectively guaranteed, thereby improving the heat exchange efficiency between the second section 322 and the bottom surface of the battery cell 2. In specific embodiments, the percentage of the projected area of ​​the blocking region 323 along the height direction to the area of ​​the second section 322 can be selected from specific values ​​such as 20%, 30%, 35%, 45%, and 50%, and is not limited here.

[0049] like Figure 4 As shown, in one embodiment of this application, at least two blocking regions 323 are provided within the flow guide, and the area of ​​all blocking regions 323 is not exactly the same. By providing at least two blocking regions 323 with different area sizes within the flow guide, the overall flow guiding effect of the blocking regions 323 can be effectively improved while limiting the total area of ​​each blocking region 323. This ensures that the heat exchange liquid in the edge region of the second section 322 can also fully participate in the circulation flow, preventing the formation of dead zones and improving the heat exchange efficiency between the second section 322 and the bottom surface of the battery cell 2.

[0050] Furthermore, such as Figure 4 As shown, in one embodiment of this application, the projections of all blocking regions 323 along the first direction do not completely overlap. When the projections of the blocking regions 323 along the first direction completely overlap, after the heat exchange liquid moves around the blocking region 323 near the inlet of the second section 322, the blocking region 323 on the rear side has difficulty in guiding the flow, and a dead zone is easily formed between adjacent blocking regions 323. Therefore, when the projections of all blocking regions 323 along the first direction do not completely overlap, it can be effectively ensured that the blocking region 323 on the rear side of the heat exchange liquid flow direction can also play a guiding role, and the formation of a dead zone between adjacent blocking regions 323 can be avoided.

[0051] like Figure 4 As shown, the distance between all blocking zones 323 and the edge of the second section 322 is k mm, where k mm satisfies 3 mm ≤ k mm ≤ 15 mm. When the distance k mm between all blocking zones 323 and the edge of the second section 322 is less than 3 mm, the resistance to the heat exchange liquid flowing through the gap between the blocking zones 323 and the edge of the second section is relatively large, affecting the flow velocity of the heat exchange liquid in the flow channel 32. When the distance k mm between all blocking zones 323 and the edge of the second section 322 is greater than 15 mm, a partial dead zone may still form at the edge of the second section 322, making it difficult to completely avoid the formation of dead zones.

[0052] Therefore, when the distance between all the blocking zones 323 and the edge of the second section 322 is k mm, and k mm satisfies 3 mm ≤ k mm ≤ 15 mm, not only is the resistance to the heat exchange liquid flowing through the gap between the blocking zone 323 and the edge of the second section small, but the impact on the flow velocity of the heat exchange liquid in the flow channel 32 is also small, and the formation of dead zones at the edge of the second section 322 can be completely avoided. In specific embodiments, the distance k mm between the blocking zone 323 and the edge of the second section 322 can be selected from specific values ​​such as 3 mm, 5 mm, 8 mm, 10 mm, and 15 mm. The distances between each blocking zone 323 and the edge of the second section 322 can be the same or not exactly the same, and no restriction is imposed here.

[0053] Specifically, such as Figure 4 As shown, in one embodiment of this application, the shape of the blocking region 323 includes at least one of a circle, an ellipse, and a polygon. A blocking region 323 that is circular, elliptical, or polygonal can effectively prevent the heat exchange liquid in the flow channel 32 from passing directly from the inlet to the outlet, thus playing a guiding role. It is understood that the blocking region 323 can be at least one of a circle, an ellipse, or a polygon, and can also be other shapes, which are not limited herein.

[0054] like Figure 2 As shown, in one embodiment of this application, for at least one battery cell 2, the projection of the first section 321 of at least one flow channel 32 along the height direction of the battery cell 2 at least partially overlaps with the projection of the bottom surface of the battery cell 2 along the height direction, and the overlapping area is a defined heat exchange area; the width of the defined heat exchange area along the second direction is M mm, the width of the bottom surface of the battery cell 2 along the second direction is N mm, and M / N satisfies 0.1≤M / N≤0.5.

[0055] It is understood that the aforementioned defined heat exchange area is the area where the first section 321 and the bottom surface of the battery cell 2 are directly in contact with each other, and the first section 321 of the flow channel 32 directly exchanges heat with the bottom surface of the battery cell 2 through the defined heat exchange area.

[0056] When the ratio M / N between the width M mm of the heat exchange area along the second direction and the width N mm of the bottom surface of the battery cell 2 along the second direction is less than 0.1, the width of the heat exchange area is too small, which can easily affect the heat exchange efficiency between the first section 321 and the bottom surface of the battery cell 2, and thus affect the overall heat exchange efficiency between the flow channel 32 and the battery cell 2. When the ratio M / N between the width M mm of the heat exchange area along the second direction and the width N mm of the bottom surface of the battery cell 2 along the second direction is greater than 0.5, the width of the heat exchange area is too large, which not only affects the area that the explosion-proof valve 23 can be arranged in, but also makes the distance between the first section 321 and the explosion-proof valve 23 too close. When the explosion-proof valve 23 of any battery cell 2 sprays fluid downward, the side wall of the flow channel 32 is prone to breakage and heat exchange liquid leakage, which can affect the normal operation of other battery cells 2.

[0057] Therefore, when the ratio M / N between the width M mm of the heat exchange area along the second direction and the width N mm of the bottom surface of the battery cell 2 along the second direction satisfies 0.1 ≤ M / N ≤ 0.5, it not only ensures the heat exchange efficiency between the first section 321 and the bottom surface of the battery cell 2, and reduces the flow resistance of the liquid flowing through the first section 321 to increase the flow velocity of the heat exchange liquid in the flow channel 32, thus affecting the heat exchange efficiency, it also leaves space for the arrangement of the explosion-proof valve 23, avoiding situations such as the side wall of the flow channel 32 breaking or the heat exchange liquid leaking when the explosion-proof valve 23 sprays fluid downwards, ensuring that other battery cells 2 continue to work normally, and improving the working safety of the battery pack in this embodiment. In specific embodiments, the above ratio M / N can be 0.1, 0.15, 0.2, 0.3, 0.5, etc., which will not be elaborated here.

[0058] like Figure 2 As shown, in one embodiment of this application, for at least one battery cell 2, the projections of the first sections 321 of two adjacent flow channels 32 arranged along the second direction along the height direction of the battery cell 2 at least partially coincide with the projection of the bottom surface of the battery cell 2 along the height direction. That is, for this battery cell 2, there are two adjacent first sections 321 of the flow channels 32 that can exchange heat with the bottom surface of the battery cell 2. In this case, the defined heat exchange area includes the sum of the overlapping areas of the first sections 321 of the two flow channels 32 and the bottom surface of the battery cell 2, and its width M mm is the sum of the widths of the two parts.

[0059] In another embodiment of this application, for at least one battery cell 2, the projection of the first section 321 of only one flow channel 32 along the height direction of the battery cell 2 at least partially coincides with the projection of the bottom surface of the battery cell 2 along the height direction.

[0060] That is, for the battery cell 2, only the first section 321 of the flow channel 32 can exchange heat with the bottom surface of the battery cell 2. In this case, the width of the heat exchange area M mm is defined as the width of the area.

[0061] Furthermore, such as Figure 2 As shown, in one embodiment of this application, the width M mm of the heat exchange area along the second direction is defined as 3 mm ≤ M mm ≤ 15 mm. When the width M mm of the heat exchange area along the second direction is less than 3 mm, the width of the heat exchange area is too small, which can easily affect the heat exchange efficiency between the first section 321 and the bottom surface of the battery cell 2, and thus affect the overall heat exchange efficiency between the flow channel 32 and the battery cell 2. When the width M mm of the heat exchange area along the second direction is greater than 15 mm, the width of the heat exchange area is too large, which not only affects the area that the explosion-proof valve 23 can be arranged in, but also makes the distance between the first section 321 and the explosion-proof valve 23 too close. When the explosion-proof valve 23 of any battery cell 2 sprays fluid downward, the side wall of the flow channel 32 is prone to breakage and heat exchange liquid leakage, which can affect the normal operation of other battery cells 2.

[0062] Therefore, when the width M mm of the heat exchange area along the second direction is limited to 3 mm ≤ M mm ≤ 15 mm, it not only ensures the heat exchange efficiency between the first section 321 and the bottom surface of the battery cell 2, and reduces the flow resistance of the liquid flowing through the first section 321 to increase the flow velocity of the heat exchange liquid in the flow channel 32, thus affecting the heat exchange efficiency, but also provides space for the arrangement of the explosion-proof valve 23, avoiding situations such as the side wall of the flow channel 32 breaking or the heat exchange liquid leaking when the explosion-proof valve 23 sprays fluid downwards, ensuring that other battery cells 2 continue to work normally, and improving the working safety of the battery pack in this embodiment. In specific embodiments, the value of the width M mm of the heat exchange area along the second direction can be 3 mm, 5 mm, 10 mm, 12 mm, 15 mm, etc., which will not be elaborated here.

[0063] like Figure 2 As shown, in one embodiment of this application, the width N mm of the bottom surface of the battery cell 2 along the second direction satisfies 30 mm ≤ N mm ≤ 55 mm.

[0064] When the width N mm of the bottom surface of the battery cell 2 along the second direction is less than 30 mm, the width N mm of the bottom surface of the battery cell 2 is too small. Not only is it difficult to arrange the explosion-proof valve 23, but it will also affect the heat exchange area between the first section 321 and the second section 322 of the flow channel 32 and the bottom surface of the battery cell 2, thereby affecting the overall heat exchange efficiency between the flow channel 32 and the battery cell 2.

[0065] When the width N mm of the bottom surface of the battery cell 2 along the second direction is greater than 55 mm, the width N mm of the bottom surface of the battery cell 2 is too large, and the bottom surface width occupied by a single battery cell 2 is large, thereby reducing the total number of battery cells 2 that can be arranged in the battery pack of this application embodiment.

[0066] Therefore, when the width N mm of the bottom surface of the battery cell 2 along the second direction satisfies 30 mm ≤ N mm ≤ 55 mm, it not only facilitates the arrangement of the explosion-proof valve 23 on the bottom surface of the battery cell 2, but also ensures the heat exchange area between the first section 321 and the second section 322 of the flow channel 32 and the bottom surface of the battery cell 2, thereby ensuring the overall heat exchange efficiency between the flow channel 32 and the battery cell 2. In a specific embodiment, the value of the width N mm of the bottom surface of the battery cell 2 along the second direction can be 30 mm, 35 mm, 40 mm, 42 mm, 55 mm, etc., which will not be elaborated here.

[0067] like Figure 2 As shown, in one embodiment of this application, along the second direction, the distance between the heat exchange area and the explosion-proof valve 23 is defined as D mm, where D mm satisfies 3 mm ≤ D mm ≤ 15 mm.

[0068] When the distance between the heat exchange area and the explosion-proof valve 23 is less than 3 mm (D mm), the distance between the first section 321 and the explosion-proof valve 23 is too close. When any battery cell 2's explosion-proof valve 23 sprays fluid downwards, the sidewall of the flow channel 32 is prone to breakage and heat exchange liquid leakage, affecting the normal operation of other battery cells 2. When the distance between the heat exchange area and the explosion-proof valve 23 is greater than 15 mm (D mm), the width of the heat exchange area is limited, which can easily affect the heat exchange efficiency between the first section 321 and the bottom surface of the battery cell 2, and thus affect the overall heat exchange efficiency between the flow channel 32 and the battery cell 2.

[0069] Therefore, when the distance D mm between the heat exchange area and the explosion-proof valve 23 satisfies 3mm ≤ D mm ≤ 15mm, not only is space provided for the arrangement of the explosion-proof valve 23, preventing situations such as breakage of the sidewall of the flow channel 32 or leakage of the heat exchange liquid when the explosion-proof valve 23 sprays fluid downwards, thus ensuring the continued normal operation of other battery cells 2 and improving the working safety of the battery pack in this embodiment, but it also ensures the heat exchange efficiency between the first section 321 and the bottom surface of the battery cell 2, improving the overall heat exchange efficiency between the flow channel 32 and the battery cell 2. In specific embodiments, the value of the distance D mm between the heat exchange area and the explosion-proof valve 23 can be 3mm, 5mm, 10mm, 12mm, 15mm, etc., which will not be elaborated here.

[0070] like Figure 5As shown, in one embodiment of this application, for at least one battery cell 2, the projection of at least one flow channel 32 along the height direction of the battery cell 2 at least partially overlaps with the projection of the bottom surface of the battery cell 2 along the height direction, and the overlapping area is the total heat transfer area; the area of ​​the total heat transfer area is S mm. 2 The bottom surface area of ​​battery cell 2 is T mm. 2 S / T satisfies 0.4≤S / T≤0.8.

[0071] It is understandable that the above-mentioned total heat exchange area is the area where the flow channel 32 and the bottom surface of the battery cell 2 are directly in contact with each other, and the flow channel 32 exchanges heat directly with the bottom surface of the battery cell 2 through the total heat exchange area.

[0072] The total heat exchange area is S mm 2 The bottom surface area T mm of battery cell 2 2 When the ratio is less than 0.4, the total heat exchange area is too small, which can easily affect the heat exchange efficiency between the flow channel 32 and the bottom surface of the battery cell 2; when the total heat exchange area S mm 2 The bottom surface area T mm of battery cell 2 2 When the ratio is greater than 0.8, the total heat exchange area is too large, which not only affects the area that can be arranged for the explosion-proof valve 23, but also makes the distance between the flow channel 32 and the explosion-proof valve 23 too close. When the explosion-proof valve 23 of any battery cell 2 sprays fluid downward, the side wall of the flow channel 32 is prone to breakage and heat exchange liquid leakage, which affects the normal operation of other battery cells 2.

[0073] Therefore, in a total heat exchange area of ​​S mm 2 The bottom surface area of ​​battery cell 2 is T mm. 2 When the S / T ratio satisfies 0.4 ≤ S / T ≤ 0.8, not only can the heat exchange efficiency between the flow channel 32 and the bottom surface of the battery cell 2 be guaranteed, but space can also be provided for the arrangement of the explosion-proof valve 23. This avoids situations such as the side wall of the flow channel 32 breaking or the heat exchange liquid leaking when the explosion-proof valve 23 sprays fluid downwards, ensuring that other battery cells 2 continue to work normally and improving the working safety of the battery pack in this embodiment. In specific embodiments, the above ratio S / T can be 0.4, 0.5, 0.55, 0.6, 0.8, etc., which will not be elaborated here.

[0074] This application also provides an electrical device that includes at least one of the aforementioned battery packs. It is understood that this electrical device can be any type of electrical device, such as an electric vehicle, an appliance with a battery pack, or an energy storage device, and is not limited thereto.

[0075] It should be noted that the elements described in the above specific embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, this application will not describe the various possible combinations separately.

[0076] It should be understood that multiple components and / or parts can be provided by a single integrated component or part. Alternatively, a single integrated component or part can be divided into multiple separate components and / or parts. The use of the public designation "a" or "an" to describe a component or part does not imply the exclusion of other components or parts.

[0077] It should be understood that while terms such as "first" or "second" may be used in this application to describe various elements, these elements are not limited by these terms; these terms are merely used to distinguish one element from another. The terminology used in one or more embodiments of this application is for the purpose of describing particular embodiments only and is not intended to limit the scope of one or more embodiments of this application. The singular forms "a," "the," and "the" as used in one or more embodiments of this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term "and / or" as used in one or more embodiments of this application refers to and includes any or all possible combinations of one or more associated listed items.

[0078] In this document, terms such as "up," "down," "front," "back," "left," and "right" are used only to indicate the relative positional relationship between related parts, and not to define the absolute position of these related parts. Terms such as "equal" and "same" are not strict mathematical and / or geometric limitations, and also include errors that are understandable to those skilled in the art and permissible in manufacturing or use. Unless otherwise stated, numerical ranges in this document include not only the entire range within its two endpoints, but also several subranges contained therein.

[0079] The basic principles of this application have been described above with reference to specific embodiments. However, it should be noted that the advantages, benefits, and effects mentioned in this application are merely examples and not limitations, and should not be considered as essential features of the embodiments of this application. Furthermore, the specific details disclosed above are for illustrative and facilitative purposes only, and are not limitations. These details do not limit the application to the necessity of employing the aforementioned specific details for implementation.

[0080] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A battery pack, characterized in that, include: The battery pack (20) includes at least two battery cells (2), and at least two battery cells (2) arranged along a first direction form a battery column (28); an explosion-proof valve (23) is provided on the bottom surface of the battery cell (2). A heat exchange plate (30) is disposed at the bottom of the battery pack (20) and exchanges heat with the battery cell (2). The heat exchange plate (30) is provided with at least one flow channel (32), which extends along a first direction and is filled with heat exchange liquid to exchange heat with the battery cell (2). The flow channel (32) has a first section (321) and a second section (322). The projection of the explosion-proof valve (23) along the second direction is completely within the projection of the first section (321) along the second direction, and the projection of the explosion-proof valve (23) along the second direction is completely outside the projection of the second section (322) along the second direction. The second direction is perpendicular to the first direction and perpendicular to the height direction of the battery cell (2). The first segment (321) has a maximum width of A mm in the second direction, and the second segment (322) has a maximum width of B mm in the second direction. A / B satisfies 0.1≤A / B≤0.

3.

2. The battery pack according to claim 1, characterized in that, The maximum width A mm of the first segment (321) in the second direction satisfies 10 mm ≤ A mm ≤ 80 mm.

3. The battery pack according to claim 1, characterized in that, The maximum width B mm of the second section (322) in the second direction satisfies 50 mm ≤ B mm ≤ 100 mm.

4. The battery pack according to claim 1, characterized in that, For at least one of the battery cells (2), the projection of the first section (321) of at least one of the flow channels (32) along the height direction of the battery cell (2) at least partially overlaps with the projection of the bottom surface of the battery cell (2) along the height direction, and the overlapping area is a defined heat exchange area. The width of the defined heat exchange area along the second direction is M mm, and the width of the bottom surface of the battery cell (2) along the second direction is N mm, where M / N satisfies 0.1≤M / N≤0.

5.

5. The battery pack according to claim 4, characterized in that, For at least one of the battery cells (2), the projection of the first section (321) of two adjacent flow channels (32) arranged along the second direction along the height direction of the battery cell (2) is at least partially coincident with the projection of the bottom surface of the battery cell (2) along the height direction.

6. The battery pack according to claim 4, characterized in that, For at least one of the battery cells (2), the projection of the first section (321) of only one of the flow channels (32) along the height direction of the battery cell (2) at least partially coincides with the projection of the bottom surface of the battery cell (2) along the height direction.

7. The battery pack according to claim 4, characterized in that, The width M mm of the defined heat exchange area along the second direction satisfies 3 mm ≤ M mm ≤ 15 mm.

8. The battery pack according to claim 4, characterized in that, The width N mm of the bottom surface of the battery cell (2) along the second direction satisfies 30 mm ≤ N mm ≤ 55 mm.

9. The battery pack according to claim 4, characterized in that, Along the second direction, the distance between the defined heat exchange area and the explosion-proof valve (23) is D mm, where D mm satisfies 3 mm ≤ D mm ≤ 15 mm.

10. The battery pack according to claim 4, characterized in that, For at least one of the battery cells (2), the projection of at least one of the flow channels (32) along the height direction of the battery cell (2) at least partially coincides with the projection of the bottom surface of the battery cell (2) along the height direction, and the overlapping area is the total heat exchange area; the area of ​​the total heat exchange area is S mm. 2 The bottom surface area of ​​the battery cell (2) is T mm. 2 S / T satisfies 0.4≤S / T≤0.

8.

11. The battery pack according to any one of claims 1 to 10, characterized in that, The second section (322) is provided with a flow guide, which is configured to allow heat exchange liquid flowing into the second section (322) to flow to the two end edge regions of the second section (322) in the second direction, and / or allow heat exchange liquid in the two end edge regions of the second section (322) in the second direction to flow out of the second section (322).

12. The battery pack according to claim 11, characterized in that, The flow guide includes a flow guide plate configured to form an angle with the first direction, so that the heat exchange liquid moves along the flow guide plate.

13. The battery pack according to claim 11, characterized in that, The flow guide includes a blocking area (323), which together with the outer edge of the flow channel (32) forms the flow channel (32). The projection of the blocking area (323) in the first direction at least partially coincides with the projection of at least one of the entrance and exit of the second segment (322) in the first direction.

14. The battery pack according to claim 13, characterized in that, The projected area of ​​the blocking area (323) along the height direction accounts for 20% to 50% of the area of ​​the second section (322).

15. The battery pack according to claim 13, characterized in that, The guide member is provided with at least two blocking areas (323), and the area of ​​all the blocking areas (323) is not exactly the same.

16. The battery pack according to claim 13, characterized in that, The projections of all the blocking areas (323) along the first direction do not completely overlap.

17. The battery pack according to claim 13, characterized in that, The distance between all the blocking areas (323) and the edge of the second segment (322) is k mm, where k mm satisfies 3 mm ≤ k mm ≤ 15 mm.

18. The battery pack according to claim 13, characterized in that, The shape of the blocking area (323) includes at least one of the following: circle, ellipse, and polygon.

19. An electrical appliance, characterized in that, Includes the battery pack according to any one of claims 1 to 18.

Images