Uniformly heated square shell power cell

Abstract

The utility model provides a kind of even heating type square shell power cell, including shell, cover and bare cell, the positive, negative pole lug of bare cell is connected with the positive, negative pole post of cover, its stacking arrangement makes the surface area maximum face each other parallel;Heat partition plate along width direction is equipped in shell, and its at least opposite two ends are fixed with shell, and inside space is separated into several sub-cavities, bare cell is placed in sub-cavity and is in close contact with heat partition plate, and the bottom of heat partition plate and / or central region is equipped with overflow groove, adjacent overflow groove is arranged staggeredly to make electrolyte flow through adjacent sub-cavity to form arc flow path;The structure is in close contact with bare cell by heat partition plate and increases heat transfer area, cooperate electrolyte arc flow path, can quickly export heat to avoid local overheating, promote temperature balance, to improve cell thermal stability, prolong service life.

Description

Technical Field

[0001] This utility model relates to a square-shell power battery cell, and more particularly to a square-shell power battery cell with uniform heat distribution. Background Technology

[0002] With the rapid development of new energy vehicles and energy storage systems, prismatic power cells are widely used as key energy storage units. During charging and discharging, prismatic power cells generate a significant amount of heat due to internal electrochemical reactions and current conduction. If this heat cannot be dissipated promptly and evenly, it will lead to uneven temperature distribution within the cell. This will not only cause localized overheating, accelerating the degradation of active materials and shortening cell lifespan, but also increase performance differences between prismatic power cells, affecting the overall consistency of battery modules composed of these cells. In extreme cases, localized overheating may even induce thermal runaway, posing serious safety hazards.

[0003] Currently, common thermal management solutions mostly involve installing heat sinks, water-cooled plates, and other devices on the outside of the prismatic battery cell to dissipate heat. However, these external heat dissipation structures typically only cool the outer surface of the prismatic battery cell and are insufficient to effectively improve the internal heat distribution. Furthermore, traditional prismatic battery cells lack adequate design considerations for electrolyte flow paths, resulting in largely disordered electrolyte flow within the cell, failing to form efficient convective heat transfer channels and thus limiting the uniform transfer and diffusion of internal heat. Therefore, achieving efficient heat dissipation and heat equalization within the prismatic battery cell has become a pressing technological challenge. Utility Model Content

[0004] This utility model addresses at least one of the problems of square-shell battery cells in the prior art by providing a square-shell power battery cell, comprising a shell, a cover plate, and bare cells. The positive and negative tabs of the bare cells are connected to the positive and negative terminals of the cover plate. The bare cells are stacked such that the surfaces with the largest surface area are parallel to each other. A heat-spreading baffle is disposed inside the shell along its width direction. At least two opposite ends of the heat-spreading baffle are fixedly connected to the shell. The heat-spreading baffle divides the internal space of the shell into several sub-cavities. The bare cells are disposed in the sub-cavities and are in close contact with the heat-spreading baffle. Flow grooves are provided on the bottom and / or central regions of the heat-spreading baffles. The flow grooves of adjacent heat-spreading baffles are staggered, so that the electrolyte flows through the adjacent sub-cavities in an arc-shaped flow path.

[0005] In this invention, a heat-spreading baffle divides the internal space of the casing into several sub-cavities. The bare battery cell is in close contact with the heat-spreading baffle, greatly increasing the heat transfer area and allowing the heat from the battery cell to be quickly dissipated, preventing localized overheating and improving thermal stability. Simultaneously, the staggered flow channels of adjacent heat-spreading baffles guide the electrolyte to form an arc-shaped flow path, helping to carry away and disperse heat and promote temperature uniformity within the casing. The staggered arrangement of the flow channels provides an orderly and rational flow channel for the electrolyte, helping to maintain a uniform distribution of chemical substances, enhancing the battery cell's performance, and extending its service life.

[0006] Preferably, the cover plate is disposed at opposite ends of the housing, the flow channel is disposed in the central area of ​​the heat-spreading baffle, and the end of the heat-spreading baffle near the cover plate is lower than the outer wall of the housing, such that the distance between this end and the cover plate is greater than the distance between the housing and the cover plate.

[0007] In some blade-type prismatic cells, the length-to-width ratio of these cells is significantly larger, giving them an overall elongated shape. The cover plates are located at opposite ends of the casing, making it easier for heat to accumulate in the middle area of ​​the cell. The flow channel is placed in the central area of ​​the heat spreader, allowing the electrolyte to form a relatively uniform flow field distribution inside the casing during flow. This effectively improves the heat exchange efficiency inside the casing, reduces the temperature gradient, and improves the overall thermal balance performance.

[0008] Preferably, the cover plate is disposed at one end of the housing, the flow channel is disposed at the bottom area of ​​the heat-spreading baffle, and the end of the heat-spreading baffle near the cover plate is lower than the outer wall of the housing, such that the distance between this end and the cover plate is greater than the distance between the housing and the cover plate.

[0009] In most prismatic battery cells, the length-to-width ratio is closer, giving them an overall square shape, with the cover plate located at one end of the casing. A flow channel is positioned at the bottom of the heat spreader, allowing the electrolyte to form a main flow channel along the bottom of the casing. During flow, the electrolyte makes full contact with the bottom area of ​​the casing, enhancing heat exchange at the bottom and effectively improving the heat dissipation uniformity of the entire cell. Furthermore, the end of the heat spreader near the cover plate is lower than the outer wall of the casing; this space acts as a fluid confluence and buffer zone, promoting fluid dispersion and recirculation at the end, which helps reduce heat accumulation at the end and thus reduces localized temperature rise.

[0010] Preferably, the flow channels on the heat spreader are staggered along the thickness direction between adjacent heat spreaders, allowing the fluid to connect sequentially in a Z-shaped path between adjacent sub-cavities. This results in the electrolyte flowing through adjacent sub-cavities in an arc-shaped flow path, more ideally achieving an S-shaped flow path. This design significantly extends the fluid flow path inside the cell, increasing the contact time between the fluid and each region, and expanding the heat exchange area. This enables sufficient heat exchange and diffusion within the cell, effectively improving the uniformity of temperature distribution.

[0011] Preferably, the heat-spreading partition is provided with a first heat-conducting channel and a second heat-conducting channel. The first heat-conducting channel is open at both ends, and the second heat-conducting channel is closed at both ends. Both the first heat-conducting channel and the second heat-conducting channel extend along the height direction of the square-shell battery cell.

[0012] In this design, the first heat conduction channel forms a continuous heat conduction path along the height of the prismatic cell, enabling rapid transfer of localized heat to the cover plate or bottom. The partially enclosed cavity of the second heat conduction channel acts as a thermal buffer and peak clipping mechanism during charging, discharging, or fast charging. In terms of thermal management, the use of a heat-spreading separator with both the first and second heat conduction channels significantly reduces the thermal resistance between bare cell layers, improves the internal temperature distribution of the cell, and reduces the temperature difference between the center and edges, as well as between the top and bottom, creating a combined effect of rapid heat conduction and release, thus achieving a more uniform thermal field. This uniform thermal field helps improve reaction consistency, reduces localized polarization and lithium deposition, thereby extending cycle life and improving capacity retention.

[0013] Preferably, the heat spreader includes a ceramic dielectric coating area and a blank area. The ceramic dielectric coating area is disposed on the outer and upper surfaces of the heat spreader near the tab, and the blank area is disposed on the outer surface of the heat spreader away from the tab.

[0014] The ceramic dielectric coating exhibits good breakdown resistance and thermal conductivity, effectively isolating the potential difference between the heat spreader and adjacent bare cell electrodes or metal casings. Placing the ceramic dielectric coating area on the outer and upper surfaces of the heat spreader near the tabs effectively isolates the high-potential region at the tabs, preventing leakage or short circuit risks caused by metal conduction. The blank area minimizes interfacial thermal resistance and enhances heat dissipation, achieving a balance between insulation, leakage prevention, and heat dissipation performance in the heat spreader.

[0015] Preferably, the heat-spreading baffle is provided with a first heat-conducting channel and / or a second heat-conducting channel near the tab at its end, and the area near the center of the heat-spreading baffle is a solid structure, with the solid structure spaced apart from the first or second heat-conducting channel.

[0016] The tab area of ​​a battery cell is typically where current is most concentrated and heat generation is most significant. Placing heat conduction channels close to the tabs can significantly shorten the heat transfer path from the heat source to the heat conduction channels, allowing localized heat to be conducted more quickly, thereby effectively reducing the temperature rise of the tabs and the busbar area. The central part of the heat spreader is designed as a solid structure, which can establish a stable heat transfer path between the heat conduction channels, ensuring overall temperature uniformity. Attached Figure Description

[0017] Figure 1This is a three-dimensional schematic diagram of a heat-equalizing square-shell power battery cell provided by this utility model;

[0018] Figure 2 This is a partial three-dimensional schematic diagram of a heat-equalizing square-shell power battery cell provided by this utility model;

[0019] Figure 3 This is a partial three-dimensional schematic diagram of a heat-equalizing square-shell power battery cell provided by this utility model;

[0020] Figure 4 This is a three-dimensional schematic diagram of another type of homogeneous heat-generating square-shell power battery cell provided by this utility model;

[0021] Figure 5 This is a front view of another type of homogeneous heat-generating square-shell power battery cell provided by this utility model;

[0022] Figure 6 This is a partial three-dimensional schematic diagram of another type of homogeneous heat-generating square-shell power battery cell provided by this utility model;

[0023] Figure 7 This is a partial three-dimensional schematic diagram of another type of homogeneous heat-generating square-shell power battery cell provided by this utility model;

[0024] Figure 8 This is a schematic diagram of another heat-equalizing partition provided by this utility model;

[0025] Among them, 1. shell, 2. cover plate, 3. bare battery cell, 4. heat dissipation plate, 41. flow channel, 42. first heat conduction channel, and 43. second heat conduction channel. Detailed Implementation

[0026] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Example 1

[0028] like Figure 1-3As shown, this embodiment provides a heat-equalizing prismatic power battery cell, including a housing 1, a cover plate 2, and bare cells 3. The positive and negative terminals of the cover plate 2 are on the same side. The positive and negative terminals of the bare cells 3 are connected to the positive and negative terminals of the cover plate 2. The bare cells 3 are stacked so that the surfaces with the largest surface area are parallel to each other. A heat-equalizing partition 4 extending along the width direction is provided inside the housing 1. The two ends of the heat-equalizing partition 4 are fixedly connected to the housing 1, dividing the internal space into multiple sub-cavities. The bare cells 3 are disposed in the sub-cavities and are in close contact with the heat-equalizing partition 4, which significantly increases the heat transfer area in a limited space, allowing the heat generated by the cell to be efficiently conducted to the housing 1 and avoiding local overheating.

[0029] There are two heat-spreading baffles 4, and a flow channel 41 is provided in the bottom area. The flow channels 41 of adjacent heat-spreading baffles 4 are staggered along the width direction, so that the electrolyte forms an arc-shaped flow path between adjacent sub-cavities. This structure can guide the electrolyte to circulate in an orderly manner inside the cell, prolong the fluid residence time and enhance the turbulent mixing effect, thereby improving the fluid heat exchange efficiency, promoting the balanced diffusion of heat in each area, and effectively reducing the temperature difference between different areas.

[0030] By combining the heat-spreading baffles 4 arranged in staggered flow channels 41 with the tightly fitted bare battery cells 3, the battery cell achieves a synergistic effect of heat conduction and convection cooling. On the one hand, the heat-spreading baffles 4 significantly improve the thermal conductivity of solids; on the other hand, the flow of electrolyte in the staggered channels forms dynamic cooling and heat dispersion, taking into account multiple effects such as temperature uniformity, heat dissipation, and chemical reaction uniformity, thereby improving the cycle stability and service life of the battery cell.

[0031] Example 2

[0032] like Figures 4-7 As shown, unlike Embodiment 1, this embodiment provides a heat dissipation structure suitable for blade-type prismatic battery cells. Cover plates 2 are disposed at opposite ends of the housing 1, and heat dissipation baffles 4 are arranged along the length of the housing 1. The end of the baffle near the cover plate 2 is lower than the outer wall of the housing 1, creating a large gap between this end and the cover plate 2. A flow channel 41 is formed in the central region of the heat dissipation baffle 4, creating a flow guiding structure within the housing 1. During flow, the electrolyte can pass through the central region and adjacent heat dissipation baffles 4, achieving connectivity and circulation, thereby establishing an orderly fluid channel within the battery cell.

[0033] For long, strip-shaped blade cells with a large length-to-width ratio, this structure can significantly improve the problem of heat accumulation in the central region. By arranging flow channels 41 in the central region, the electrolyte forms a relatively uniform flow field distribution inside the cell, extending the contact path between the fluid and the heating surface and improving heat exchange efficiency; at the same time, the recessed baffle design at the ends forms a flow guiding and buffering space, reducing flow resistance and local temperature difference.

[0034] Example 3

[0035] like Figure 8 As shown, the difference between this embodiment and Embodiment 1 is that a first heat-conducting channel 42 and a second heat-conducting channel 43 are provided inside the heat-spreading partition 4. The first heat-conducting channel 42 is open at both ends, forming a continuous heat-conducting path along the height direction of the prismatic battery cell, which can quickly conduct local heat to the cover plate 2 or the bottom during the operation of the battery cell; the second heat-conducting channel 43 is closed at both ends and has a hollow internal structure, which is used to absorb instantaneous heat under high-power conditions such as charging, discharging or fast charging, and plays a role in heat buffering and peak reduction. Both the first heat-conducting channel 42 and the second heat-conducting channel 43 extend along the height direction of the battery cell, so that heat can be efficiently transferred and diffused in the vertical direction.

[0036] By incorporating a combination of open and closed heat-conducting channels, the heat-spreading plate 4 achieves a synergistic function of heat conduction and heat storage. On one hand, the open channels reduce the thermal resistance between the three layers of the bare battery cell, enabling rapid heat conduction and dissipation; on the other hand, the closed channels provide temporary heat storage and slow release, mitigating temperature fluctuations. This composite heat-conducting structure significantly improves the internal temperature distribution of the battery cell, reducing the temperature difference between the center and the edges, and between the upper and lower ends, thus forming a stable and uniform thermal field.

[0037] The embodiments described above are merely illustrative of several implementations of this utility model, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model patent should be determined by the appended claims.

Claims

1. A heat-equalizing square-shell power battery cell, comprising a shell, a cover plate, and bare cells, wherein the positive and negative tabs of the bare cells are connected to the positive and negative terminals of the cover plate, and the bare cells are stacked such that the surfaces with the largest surface area are parallel to each other, characterized in that... The housing is provided with a heat-spreading baffle along the width direction. At least two opposite ends of the heat-spreading baffle are fixedly connected to the housing. The heat-spreading baffle divides the internal space of the housing into several sub-cavities. The bare battery cell is disposed in the sub-cavities and is in close contact with the heat-spreading baffle. The bottom area and / or central area of ​​the heat-spreading baffle is provided with flow channels. The flow channels of adjacent heat-spreading baffles are staggered, so that the electrolyte flows through the adjacent sub-cavities to form an arc-shaped flow path.

2. The heat-equalizing prismatic power cell according to claim 1, characterized in that, The cover plate is disposed at opposite ends of the shell, the flow channel is disposed in the central area of ​​the heat-spreading baffle, and the end of the heat-spreading baffle near the cover plate is lower than the outer wall of the shell, such that the distance between this end and the cover plate is greater than the distance between the shell and the cover plate.

3. The heat-equalizing prismatic power cell according to claim 1, characterized in that, The cover plate is disposed at one end of the shell, and the flow channel is disposed at the bottom area of ​​the heat-spreading baffle. The end of the heat-spreading baffle near the cover plate is lower than the outer wall of the shell, such that the distance between this end and the cover plate is greater than the distance between the shell and the cover plate.

4. The heat-equalizing prismatic power cell according to claim 2 or 3, characterized in that, The flow channels on the heat-spreading baffles are staggered along the thickness direction between adjacent heat-spreading baffles, so that the fluid is connected sequentially in a Z-shaped path between adjacent sub-cavities, and the electrolyte flows through the adjacent sub-cavities to form an arc-shaped flow path.

5. The heat-equalizing prismatic power cell according to claim 1, characterized in that, The heat-spreading partition is provided with a first heat-conducting channel and a second heat-conducting channel. The first heat-conducting channel is open at both ends, and the second heat-conducting channel is closed at both ends. Both the first heat-conducting channel and the second heat-conducting channel extend along the height direction of the square-shell battery cell.

6. The heat-equalizing prismatic power cell according to claim 5, characterized in that, The heat spreader includes a ceramic dielectric coating area and a blank area. The ceramic dielectric coating area is disposed on the outer and upper surfaces of the heat spreader near the tab, and the blank area is disposed on the outer surface of the heat spreader away from the tab.

7. The heat-equalizing prismatic power cell according to claim 5, characterized in that, The heat-spreading baffle is provided with a first heat-conducting channel and / or a second heat-conducting channel near the tab at its end, and the area near the center of the heat-spreading baffle is a solid structure, with the solid structure spaced apart from the first or second heat-conducting channel.

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