Single cell

Abstract

The application discloses a single battery, comprising: a shell provided with a containing cavity; an electrode assembly assembled in the containing cavity, the electrode assembly leading out a tab; a top cover assembled on the shell to seal the containing cavity, the top cover comprising a top cover sheet and a pole post assembly penetrating through the top cover sheet, the tab being connected with the pole post assembly; and a suction cooling piece assembled on the tab for sucking electrolyte in the shell. The suction cooling piece sucks and stores the electrolyte injected into the shell, thereby gathering the electrolyte at the tab, cooling the tab with the electrolyte, avoiding high temperature near the tab to cause the active material in the region to precipitate lithium, age prematurely and the like, improving the cycle life of the battery, and the electrolyte can long-term soak the tab, so that the tab does not need to be continuously supplied with a cooling medium to cool the tab, the overall structure is simpler, and the cooling structure does not occupy a large space to reduce the energy density of the battery.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of power batteries, in particular to a single battery. BACKGROUND

[0002] At present, power battery enterprises are booming, and the production of batteries is gradually increasing. Improving the energy density of the battery and ensuring the competitiveness of the battery in the market are closely concerned by manufacturers. Among them, the square shell battery gradually occupies a leading position in the market due to the advantages of high grouping efficiency, large energy density, and fast production speed.

[0003] However, the mechanical parts of the square shell battery in the prior art have the defects of large heat generation and high temperature. In particular, the root area of the tab of the square shell battery has large heat generation and small heat capacity due to the thin thickness of the tab, which leads to high temperature at the tab root area under the conditions of fast charging and fast discharging of the battery, and drives the temperature of the nearby active material area to exceed the standard, thereby causing the active material in the area to easily lithiumize and age prematurely, affecting the cycle performance of the entire battery. SUMMARY

[0004] The technical problem to be solved by the present application is to overcome the defect of excessive temperature of the tab of the battery in the prior art during operation, and to provide a single battery.

[0005] The present application solves the above technical problems by the following technical scheme: a single battery, comprising:

[0006] a housing provided with a containing cavity;

[0007] an electrode assembly assembled in the containing cavity, the electrode assembly having a tab drawn out;

[0008] a top cover assembled on the housing to seal the containing cavity, the top cover comprising a top cover sheet and a pole assembly penetrating the top cover sheet, the tab being connected with the pole assembly;

[0009] an adsorption cooling part assembled on the tab for adsorbing and storing the electrolyte in the housing, thereby concentrating the electrolyte at the tab and cooling the tab with the electrolyte, avoiding the temperature of the area near the tab being too high to cause the active material in the area to lithiumize and age prematurely, and improving the cycle life of the battery.

[0010] In this scheme, the adsorption cooling part adsorbs and stores the electrolyte injected into the housing, thereby concentrating the electrolyte at the tab, cooling the tab with the electrolyte, avoiding the temperature of the area near the tab being too high to cause the active material in the area to lithiumize and age prematurely, and improving the cycle life of the battery. Moreover, the electrolyte can long-term soak the tab, and there is no need to continuously introduce a cooling medium to cool the tab, so that the overall structure is simpler, and the cooling structure does not occupy a large space to reduce the energy density of the battery.

[0011] Preferably, the adsorption cooling element is provided with a channel penetrating through the adsorption cooling element, the tab includes a root portion and a connecting portion connected in sequence, the connecting portion is arranged in the channel, and the connecting portion is connected with the pole column assembly.

[0012] In the scheme, the tab is arranged in the channel in the adsorption cooling element, the connecting portion in the channel can be soaked by the electrolyte of the adsorption cooling element, thereby increasing the contact area of the tab and the adsorption cooling element and improving the cooling effect on the tab, the adsorption cooling element can position the tab, and the tab is prevented from shaking in use and is limited to be inserted into the accommodating cavity.

[0013] Preferably, the extending direction of the channel is arranged at an angle with the thickness direction of the adsorption cooling element.

[0014] In the scheme, the extending path of the channel in the adsorption cooling element is lengthened, that is, the overall length of the channel is increased, the length of the connecting portion of the tab in the channel is increased, the contact area of the tab and the adsorption cooling element is increased, and the cooling effect is further improved.

[0015] Preferably, the included angle between the extending direction of the connecting portion in the channel and the extending direction of the channel is not greater than 10°.

[0016] In the scheme, when the included angle is not greater than 10°, the area of the connecting portion in the channel and the side wall of the channel is greatly increased, the cooling efficiency of the adsorption cooling element is improved relative to air cooling without abutting.

[0017] Preferably, the adsorption cooling element is provided with a cavity at one end of the channel close to the root portion, and the root portion is matched with the cavity and embedded in the cavity.

[0018] In the scheme, the cavity is arranged at the channel, so that the connecting portion can extend in the cavity and the channel in sequence, which facilitates the cooperation and installation of the adsorption cooling element and the tab, and the root portion of the tab generates a large amount of heat, and the temperature of the region is high. By embedding the root portion in the cavity of the adsorption cooling element, the adsorption cooling element is abutted with the root portion, thereby improving the cooling efficiency.

[0019] Preferably, the cavity is a V-shaped groove.

[0020] In the scheme, the middle of the root portion of the tab is more protruding, and the edge is low. The V-shaped groove-shaped cavity is convenient for cooperation with the root portion of the tab, the adsorption cooling element is more closely abutted with the root portion, and installation is facilitated.

[0021] Preferably, the connecting portion is reversely bent after penetrating out of the channel and arranged close to the adsorption cooling element.

[0022] In the scheme, the structure is arranged, the part of the connecting part bending can limit the adsorption cooling piece, the overall structure is more stable, and the fitting area of the tab (connecting part) and the adsorption cooling piece is increased.

[0023] Preferably, the adsorption cooling piece comprises at least two cooling units arranged in a split mode, and the at least two cooling units are spliced to form the adsorption cooling piece.

[0024] In the scheme, the structure is arranged, the cooling unit can be processed respectively, the processing efficiency is improved, and the adsorption cooling piece is convenient to install through the splicing mode.

[0025] Preferably, the number of the cooling units is two, the channel is arranged on one of the cooling units, the channel is in a rectangular structure along a cross section perpendicular to an extension direction of the channel, and the splicing direction of the cooling units is perpendicular to a length direction of the rectangular structure.

[0026] In the scheme, since the splicing direction is perpendicular to the length direction of the cross section of the channel, the extension part of the tab is more easily aligned with the channel when the cooling units are spliced along the splicing direction, so that the splicing of the cooling units is facilitated, and the channel is arranged on one of the cooling units, so that the cooling units are convenient to process.

[0027] Preferably, the number of the cooling units is two, the channel is arranged on one of the cooling units, the channel is in a rectangular structure along a cross section perpendicular to an extension direction of the channel, and the splicing direction of the cooling units is perpendicular to a length direction of the rectangular structure.

[0028] In the scheme, the structure is arranged, the shape of the connecting part of the tab can be adapted to the shape of the channel in advance when the cooling units are spliced, the shape of the connecting part does not need to be changed after splicing, the splicing step is simplified, and the installation efficiency is high.

[0029] The positive progress effect of the application is that the adsorption cooling piece absorbs and stores the electrolyte injected into the shell, so that the electrolyte is gathered at the tab, the tab is cooled by the electrolyte, the temperature near the tab is prevented from being too high to cause the active material in the region to lithiumize, age prematurely, etc., the cycle life of the battery is improved, the electrolyte can long-term soak the tab, a cooling medium does not need to be continuously introduced to cool the tab, the overall structure is simpler, the cooling structure occupies a large space, and the energy density of the battery is prevented from being reduced. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 It is a partial structure schematic view of the single battery of the embodiment 1 of the application.

[0031] Figure 2This is a partial cross-sectional view (a) of the cooling unit and electrode tabs according to Embodiment 1 of the present invention.

[0032] Figure 3 This is a partial cross-sectional view (II) of the cooling unit and electrode tabs according to Embodiment 1 of the present invention.

[0033] Figure 4 This is a schematic diagram (a) of the assembly of the cooling unit and the tab in Embodiment 1 of the present invention.

[0034] Figure 5 This is a schematic diagram (II) of the assembly of the cooling unit and the tab in Embodiment 1 of the present invention.

[0035] Figure 6 This is a schematic diagram (III) of the assembly of the cooling unit and the tabs in Embodiment 1 of the present invention.

[0036] Figure 7 This is a schematic diagram of the cooling unit in Embodiment 1 of the present invention (I).

[0037] Figure 8 for Figure 7 A schematic diagram of the assembled cooling unit.

[0038] Figure 9 This is a schematic diagram (II) of the cooling unit in Embodiment 1 of the present invention.

[0039] Figure 10 for Figure 9 A schematic diagram of the assembled cooling unit.

[0040] Figure 11 This is a schematic diagram (a) of the assembly of the cooling unit and the tabs in Embodiment 2 of the present invention.

[0041] Figure 12 This is a schematic diagram (II) of the assembly of the cooling unit and the tabs in Embodiment 2 of the present invention.

[0042] Explanation of reference numerals in the attached figures

[0043] Casing 1

[0044] Electrode 2

[0045] Root 21

[0046] Connecting part 22

[0047] pole assembly 3

[0048] Adsorption cooling component 4

[0049] Channel 41

[0050] Chamber 42

[0051] Cooling unit 43

[0052] seam 44

[0053] splicing direction A

[0054] Thickness direction B Detailed Implementation

[0055] The present invention will be further illustrated by way of embodiments below, but the present invention is not limited to the scope of the embodiments described herein.

[0056] Example 1

[0057] like Figures 1-10 As shown, this embodiment discloses a single battery, including: a housing 1 with a receiving cavity; an electrode assembly assembled in the receiving cavity, with tabs 2 extending from the electrode assembly; a top cover assembled on the housing 1 to seal the receiving cavity, the top cover including a top cover sheet and an electrode post assembly 3 passing through the top cover sheet, the tabs 2 being connected to the electrode post assembly 3; and an adsorption cooling element 4 assembled on the tabs 2 for adsorbing electrolyte in the housing 1.

[0058] In this embodiment, the adsorption cooling component 4 adsorbs and stores the electrolyte injected into the housing 1, thereby accumulating the electrolyte at the tab 2. The electrolyte is used to cool the tab 2, preventing the temperature near the tab 2 from becoming too high, which could lead to lithium plating and premature aging of the active material in that area, thus improving the cycle life of the battery. Moreover, the electrolyte can continuously wet the tab 2 without the need for a continuous cooling medium to cool the tab 2, making the overall structure simpler and avoiding the cooling structure occupying a large space, which would reduce the energy density of the battery.

[0059] Specifically, in this embodiment, the material of the adsorption cooling element 4 is the same as that of the lithium battery separator. Of course, in other alternative embodiments, other materials capable of absorbing and storing liquids, such as sponges, can also be used. The adsorption cooling element 4 is located in the upper half of the single battery cell. The adsorption cooling element 4 can absorb and store electrolyte in this upper half, allowing it to immerse the area for a long time. This compensates for the defect that when the single battery is cycled for a long time, the electrolyte flows to the lower half, causing the upper half to lack electrolyte and thus fail to cool.

[0060] like Figures 1-3 As shown, the adsorption cooling component 4 includes at least two separately arranged cooling units 43, which are spliced ​​together to form the adsorption cooling component 4. By separating the adsorption cooling component 4, the cooling units 43 can be processed individually, improving processing efficiency. Furthermore, the splicing method facilitates the installation of the adsorption cooling component 4. Of course, in other alternative embodiments, the adsorption cooling component 4 can also be integrally formed.

[0061] like Figure 2 and Figure 3As shown, the adsorption cooling piece 4 is provided with a through channel 41 penetrating the adsorption cooling piece 4, the tab 2 comprises a root 21 and a connecting portion 22 connected in sequence, the connecting portion 22 is arranged in the channel 41, and the connecting portion 22 is connected with the pole assembly 3. The tab 2 is arranged in the channel 41 inside the adsorption cooling piece 4, and the connecting portion 22 in the channel 41 can be infiltrated by the electrolyte of the adsorption cooling piece 4, so as to increase the contact area of the tab 2 and the adsorption cooling piece 4 and improve the cooling effect of the tab 2. Moreover, the adsorption cooling piece 4 can position the tab 2, prevent the tab 2 from deviating or shaking in the use process, limit the tab 2 from being inserted into the accommodating cavity, and thus reduce the risk of positive and negative short circuit and thermal runaway. Of course, in other alternative embodiments, the adsorption cooling piece 4 can also not be provided with the channel 41, and the connecting portion 22 can be arranged to pass through the gap between the adsorption cooling piece 4 and the root 21.

[0062] As shown in Figure 2 , the extension direction of the channel 41 is arranged at an angle with the thickness direction of the adsorption cooling piece 4. This structure prolongs the extension path of the channel 41 inside the adsorption cooling piece 4, that is, increases the overall length of the channel 41, so that the length of the part of the connecting portion 22 of the tab 2 in the channel 41 is increased, the contact area of the tab 2 and the adsorption cooling piece 4 is increased, and the cooling effect is further improved. Of course, in other alternative embodiments, the extension direction of the channel 41 can also be parallel to the thickness direction of the adsorption cooling piece 4.

[0063] Specifically, in the present embodiment, the included angle between the extension direction of the connecting portion 22 in the channel 41 and the extension direction of the channel 41 is not greater than 10°. When the included angle is not greater than 10°, the area of the connecting portion 22 in the channel 41 and the side wall of the channel 41 is greatly increased, and the cooling efficiency of the adsorption cooling piece 4 is improved compared with the case that the adsorption cooling piece 4 and the connecting portion 22 are not matched and are cooled by air. The angle is 0°, that is, the extension direction of the connecting portion 22 at each position in the channel 41 is consistent with the extension direction of the channel 41.

[0064] As shown in Figure 2 and Figure 3 , the adsorption cooling piece 4 is provided with a cavity 42 at one end of the channel 41 close to the root 21, and the root 21 is matched with the cavity 42 and embedded in the cavity 42. The cavity 42 is arranged at the channel 41, so that the connecting portion 22 can extend in the cavity 42 and the channel 41 in sequence, which facilitates the cooperation and installation of the adsorption cooling piece 4 and the tab 2. Moreover, the root 21 of the tab 2 generates a large amount of heat, and the temperature of this area is relatively high. By embedding the root 21 in the cavity 42 of the adsorption cooling piece 4, the adsorption cooling piece 4 is matched with the root 21, so as to improve the cooling efficiency. Of course, in other alternative embodiments, the adsorption cooling piece 4 can also not be provided with the cavity 42, that is, the bottom surface of the adsorption cooling piece 4 is matched with the root 21.

[0065] AsFigures 1-3 As shown in the embodiment, the connecting portion 22 reversely bends after passing through the passage 41 and is arranged close to the adsorption cooling member 4. The bent portion of the connecting portion 22 can position the adsorption cooling member 4, making the overall structure more stable, further preventing the tab 2 from being inserted into the accommodating cavity, and increasing the fitting area of the tab 2 (the connecting portion 22) and the adsorption cooling member 4.

[0066] Specifically, as shown in Figure 7 and Figure 8 , the cavity 42 is a V-shaped groove. The middle of the root 21 of the tab 2 is more protruding, and the edge is low. The V-shaped groove-shaped cavity 42 is convenient to cooperate with the root 21 of the tab 2, the adsorption cooling member 4 is more closely fitted with the root 21, and is also convenient to install. Of course, in other alternative embodiments, the cavity 42 can also be square or the like

[0067] As shown in Figure 9 and Figure 10 , the passage 41 is arranged on one of the cooling units 43. The passage 41 has a rectangular structure in a cross section perpendicular to the extension direction of the passage 41, and the splicing direction of the cooling unit 43 is perpendicular to the length direction of the rectangular structure. Since the splicing direction is perpendicular to the length direction of the cross section of the passage 41, the extension portion of the tab 2 is easier to align with the passage 41 when the cooling unit 43 is spliced in the splicing direction, thereby facilitating the splicing of the cooling unit 43. Moreover, the passage 41 is arranged on one of the cooling units 43, thereby facilitating the machining of the cooling unit 43.

[0068] Specifically, in the embodiment, the joint gap 44 formed after the splicing of the two cooling units 43 is parallel to the length direction of the rectangular structure, and the joint gap 44 is perpendicular to the splicing direction A. In other alternative embodiments, the joint gap 44 can also have an included angle of 0° to 90° with the splicing direction A, that is, the joint gap 44 is inclined.

[0069] Embodiment 2

[0070] The structure of the adsorption cooling member 4 of the embodiment is basically the same as that of Embodiment 1, and the differences will be described.

[0071] As shown in Figure 11 and Figure 12 , the passage 41 is arranged on two of the cooling units 43. The passage 41 has a rectangular structure in a cross section perpendicular to the extension direction of the passage 41, and the splicing direction of the cooling unit 43 is parallel to the length direction of the rectangular structure. The shape of the connecting portion 22 of the tab 2 can be adapted to the shape of the passage 41 in advance when the cooling unit 43 is spliced, and the shape of the connecting portion 22 does not need to be changed after splicing, thereby simplifying the splicing steps and improving the installation efficiency.

[0072] Specifically, in the present embodiment, the joint (not shown in the drawings) formed after the two cooling units are spliced is perpendicular to the length direction of the rectangular structure, and the joint is perpendicular to the splicing direction A. In other alternative embodiments, the joint can also form an angle of 0° to 90° with the splicing direction A, that is, the joint is inclined.

[0073] Although the specific embodiments of the present application are described above, those skilled in the art should understand that this is only an example, the protection scope of the present application is defined by the appended claims. Those skilled in the art can make various changes or modifications to these embodiments without departing from the principles and essence of the present application, and these changes and modifications all fall within the protection scope of the present application.

Claims

1. A single-cell battery, characterized in that, include: The housing has a receiving cavity; An electrode assembly is assembled within the receiving cavity, and the electrode assembly has tabs extending out from it. A top cover is fitted onto the housing to seal the receiving cavity. The top cover includes a top cover plate and an electrode assembly passing through the top cover plate. The electrode tab is connected to the electrode assembly. An adsorption cooling element is assembled on the tab and is used to adsorb the electrolyte in the housing. The adsorption cooling element has a channel that runs through it. The tab includes a root and a connecting part connected in sequence. The connecting part passes through the channel and is connected to the electrode assembly.

2. The single-cell battery as described in claim 1, characterized in that, The extension direction of the channel is set at an angle to the thickness direction of the adsorption cooling element.

3. The single-cell battery as described in claim 1, characterized in that, The angle between the extension direction of the connecting part within the channel and the extension direction of the channel is no greater than 10°.

4. The single-cell battery as described in claim 1, characterized in that, The adsorption cooling element has a chamber at one end of the channel near the root, and the root is matched with the chamber and embedded in the chamber.

5. The single-cell battery as described in claim 4, characterized in that, The chamber is a V-shaped groove.

6. The single-cell battery as described in claim 1, characterized in that, The connecting part extends out of the channel, bends in the opposite direction, and is positioned close to the adsorption and cooling component.

7. The single-cell battery as described in claim 1, characterized in that, The adsorption cooling element includes at least two separately arranged cooling units, and the at least two cooling units are spliced ​​together to form the adsorption cooling element.

8. The single-cell battery as described in claim 7, characterized in that, The number of cooling units is two, and the channel is opened on one of the cooling units. The cross-section of the channel along the extension direction perpendicular to the channel is rectangular, and the splicing direction of the cooling units is perpendicular to the length direction of the rectangular structure.

9. The single-cell battery as described in claim 7, characterized in that, The number of cooling units is two, and the channel is separately opened on the two cooling units. The cross-section of the channel along the extension direction perpendicular to the channel is rectangular, and the splicing direction of the cooling units is parallel to the length direction of the rectangular structure.

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