A battery

Abstract

An embodiment of the present application provides a battery, comprising: a first sealing film, a second sealing film, and a battery cell, wherein the first sealing film and the second sealing film cooperate to form a cavity, the battery cell is located in the cavity, the connection between the first sealing film and the second sealing film forms a top seal package, and the tab of the battery cell passes through the top seal package; the top seal package comprises a first top seal film and a second top seal film, the tab is located between the first top seal film and the second top seal film, and the shapes of the first top seal film and the second top seal film are both wavy. The wavy arrangement of the first and second top seal films increases the bonding area between the first and second top seal films, so that the top seal package has better sealing performance. The battery provided by the present application can increase the thickness of the top seal package and reduce the difficulty of the top seal package manufacturing process.

Description

Technical Field

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

[0002] Soft-pack lithium-ion batteries have the advantage of high energy density and are currently widely used in various fields.

[0003] The soft-pack lithium-ion battery includes a first sealing film, a second sealing film, and a battery cell. The battery cell is located in a cavity formed by the first sealing film and the second sealing film covering each other. To prevent the battery cell from contacting the external environment, the connection between the first sealing film and the second sealing film needs to be sealed to form a top seal package, wherein the tabs of the battery cell pass through the top seal package.

[0004] Currently, the process of sealing and forming a top-seal package based on relevant technologies is relatively difficult. Summary of the Invention

[0005] The purpose of the embodiments of the present application is to provide a battery for solving the problem of high difficulty in the process of sealing and forming a top seal package based on related technologies.

[0006] An embodiment of the present application provides a battery, comprising:

[0007] A first sealing film, a second sealing film, and a battery cell, wherein the first sealing film and the second sealing film cooperate to form a cavity, the battery cell is located in the cavity, the connection between the first sealing film and the second sealing film forms a top seal package, and the tab of the battery cell passes through the top seal package;

[0008] The top seal package includes a first top seal film and a second top seal film. The tab is located between the first top seal film and the second top seal film. The shapes of the first top seal film and the second top seal film are both wavy.

[0009] In some embodiments, the first top seal film includes a first positive electrode portion, a first shoulder portion, and a first negative electrode portion connected in sequence;

[0010] The second top seal film includes a second positive electrode portion, a second shoulder portion and a second negative electrode portion connected in sequence;

[0011] The first positive electrode portion and the second positive electrode portion are opposite to each other, the first negative electrode portion and the second negative electrode portion are opposite to each other, and the first shoulder portion and the second shoulder portion are bonded to each other;

[0012] The thickness of the top seal package corresponding to the first shoulder is smaller than the thickness of the top seal package corresponding to the first positive electrode portion, and the thickness of the top seal package corresponding to the first shoulder is smaller than the thickness of the top seal package corresponding to the first negative electrode portion.

[0013] In some embodiments, the first shoulder includes a first wave crest and a first wave valley, and the second shoulder includes a second wave crest and a second wave valley;

[0014] A thickness difference between the first corrugation peak and the first corrugation valley is greater than a thickness difference between the second corrugation peak and the second corrugation valley.

[0015] In some embodiments, a ratio of a thickness difference between the second wave crest and the second wave trough to a thickness difference between the first wave crest and the first wave trough is greater than or equal to 0.45 and less than or equal to 0.55.

[0016] In some embodiments, a thickness difference between the first wave crest and the first wave valley is greater than or equal to 20 micrometers and less than or equal to 60 micrometers.

[0017] In some embodiments, the top seal package corresponding to the first shoulder includes a first package high portion and a first package low portion, and the thickness of the first package high portion is greater than or equal to 285 micrometers and less than or equal to 315 micrometers.

[0018] In some embodiments, the thickness of the first package lower portion is greater than or equal to 255 micrometers and less than or equal to 285 micrometers.

[0019] In some embodiments, the tabs include a positive tab and a negative tab, and the positive tab and the negative tab are located on the same side of the battery cell;

[0020] The positive electrode tab is located between the first positive electrode portion and the second positive electrode portion, and the negative electrode tab is located between the first negative electrode portion and the second negative electrode portion.

[0021] In some embodiments, the top seal package corresponding to the first positive electrode portion includes a second package high portion and a second package low portion, and a thickness of the second package low portion is smaller than a thickness of the second package high portion.

[0022] In some embodiments, the thickness of the second package lower portion is greater than or equal to 765 micrometers and less than or equal to 815 micrometers; the thickness of the second package upper portion is greater than or equal to 835 micrometers and less than or equal to 885 micrometers.

[0023] In some embodiments, the top seal package corresponding to the first negative electrode portion includes a third package high portion and a third package low portion, and a thickness of the third package low portion is smaller than a thickness of the third package high portion.

[0024] In some embodiments, the thickness of the third package lower portion is greater than or equal to 565 micrometers and less than or equal to 615 micrometers; the thickness of the third package upper portion is greater than or equal to 635 micrometers and less than or equal to 685 micrometers.

[0025] The above technical solution has the following advantages or beneficial effects:

[0026] The battery provided in the embodiment of the present application utilizes the wavy setting of the first top sealing film and the second top sealing film to increase the bonding area between the first top sealing film and the second top sealing film, and to increase the bonding effect between the first top sealing film and the second top sealing film, so that the top sealing package obtains better sealing performance. The battery provided in the embodiment of the present application can increase the thickness of the top sealing package. For example, the thickness of the top sealing package can be increased while the sealing performance of the top sealing package remains unchanged, so as to reduce the process difficulty of the top sealing package. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is one of the structural diagrams of a top seal package provided in an embodiment of the present application;

[0028] Figure 2 This is a schematic structural diagram of a battery provided in an embodiment of the present application;

[0029] Figure 3 This is a structural diagram of a welded part provided by the present application;

[0030] Figure 4 This is the second structural diagram of a top seal package provided in an embodiment of the present application;

[0031] Figure 5 This is a structural schematic diagram of a positive electrode seat provided in an embodiment of the present application. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0033] See also Figure 1 and Figure 2 , Figure 1 This is one of the structural diagrams of a top seal package provided in an embodiment of the present application. Figure 2 This is a schematic diagram of the structure of a battery provided in an embodiment of the present application. Figure 1 and Figure 2 As shown, the above battery includes:

[0034] A first sealing film, a second sealing film, and a battery cell, wherein the first sealing film and the second sealing film cooperate to form a cavity, the battery cell is located in the cavity, and the connection between the first sealing film and the second sealing film forms a top seal package 70, and the tab of the battery cell passes through the top seal package 70;

[0035] The top seal package 70 includes a first top seal film and a second top seal film. The tab is located between the first top seal film and the second top seal film. The shapes of the first top seal film and the second top seal film are both wavy.

[0036] As described above, the wavy setting of the first top sealing film and the second top sealing film is utilized to increase the bonding area between the first top sealing film and the second top sealing film, and to increase the bonding effect between the first top sealing film and the second top sealing film, so that the top sealing package 70 obtains better sealing performance. That is, the battery provided in the embodiment of the present application can increase the thickness of the top sealing package 70. For example, the thickness of the top sealing package 70 can be increased while the sealing performance of the top sealing package 70 remains unchanged, so as to reduce the process difficulty of the top sealing package 70.

[0037] It should be noted that if Figure 2 As shown, after the first sealing film and the second sealing film cooperate to form the aforementioned cavity for accommodating the battery cell, the connection between the two forms a top seal package 70 and a side seal package 80, wherein the connection portion penetrated by the battery cell's tab is the top seal package 70, and the connection portion not penetrated by the battery cell's tab is the side seal package 80.

[0038] The first top seal film can be understood as forming the first seal portion of the top seal package 70, and the second top seal film can be understood as forming the second seal portion of the top seal package 70. The shapes of the first and second top seal films are both wavy, which makes the shape of the top seal package 70 also wavy. In this case, it is preferred that the side seal package 80 also be wavy in shape to reduce the manufacturing process difficulty of the side seal package 80 while maintaining the sealing performance of the battery.

[0039] For example, the connection between the first sealing film and the second sealing film can be sealed by ultrasonic welding so that the shape of the top sealing package 70 and the shape of the side sealing package 80 are both wavy. The above-mentioned ultrasonic welding method can not only save the step of preheating the tab, but also improve the heat conduction efficiency of the welded parts, thereby achieving higher sealing efficiency.

[0040] Exemplarily, the first and second sealing films may be aluminum-plastic films, each comprising a base layer, an aluminum layer disposed on the base layer, and a polypropylene layer disposed on the aluminum layer. During the sealing process, the polypropylene layer of the first and second sealing films melt and adhere to each other to form the top seal package 70 and the side seal package 80. The base layer comprises at least one of a nylon material or a polyethylene terephthalate material.

[0041] like Figure 3As shown, the above-mentioned welding parts include an ultrasonic welding seat 92 and an ultrasonic welding head 91. The ultrasonic welding seat 92 and the ultrasonic welding head 91 both include a tooth portion and a gap portion. When the connection between the first sealing film and the second sealing film is placed on the ultrasonic welding seat 92 and the ultrasonic welding head 91, the vibration friction of the ultrasonic welding head 91 and the heating of the ultrasonic welding seat 92 are used to conduct heat to the above-mentioned connection, so that the polypropylene layer at the connection is quickly melted, and the top seal package 70 and the side seal package 80 are formed after cooling.

[0042] like Figure 4 As shown, the above-mentioned wavy shape can be understood as the surface array of the top seal package 70 is provided with multiple concave areas 61 and convex areas 62, wherein the concave areas 61 are areas corresponding to the teeth of the aforementioned ultrasonic welding seat 92 (or ultrasonic welding head 91), and the convex areas 62 are areas corresponding to the gaps of the aforementioned ultrasonic welding seat 92 (or ultrasonic welding head 91).

[0043] like Figure 5 As shown, the tooth portion and the gap portion of the ultrasonic welding head 91 are both in a first trapezoid, and the two are inverted to each other, the first side length a of the first trapezoid is greater than or equal to 80 microns, and less than or equal to 200 microns; the second side length b of the first trapezoid is greater than or equal to 100 microns, and less than or equal to 200 microns; the height h of the first trapezoid is greater than or equal to 20 microns, and less than or equal to 60 microns.

[0044] like Figure 1 As shown, the tabs of the battery cell are surrounded by tab glue 50. The tab glue 50 can insulate the tabs and the top seal package 70 on the one hand, and on the other hand, it can reduce the probability of a gap between the tabs and the top seal package 70 while ensuring that the tabs can smoothly pass through the top seal package 70, thereby further improving the sealing performance of the top seal package 70.

[0045] Optionally, the first top sealing film includes a first positive electrode portion 31, a first shoulder portion 32 and a first negative electrode portion 33 connected in sequence;

[0046] The second top sealing film includes a second positive electrode portion 41, a second shoulder portion 42 and a second negative electrode portion 43 connected in sequence;

[0047] The first positive electrode portion 31 and the second positive electrode portion 41 are opposite to each other, the first negative electrode portion 33 and the second negative electrode portion 43 are opposite to each other, and the first shoulder portion 32 and the second shoulder portion 42 are bonded to each other;

[0048] The thickness of the top seal package 70 corresponding to the first shoulder 32 is smaller than the thickness of the top seal package 70 corresponding to the first positive electrode portion 31 , and the thickness of the top seal package 70 corresponding to the first shoulder 32 is smaller than the thickness of the top seal package 70 corresponding to the first negative electrode portion 33 .

[0049] As described above, the thickness of the top seal package 70 corresponding to the first shoulder 32 is limited to adapt to the situation where there are two or more tabs, and the thickness of the top seal package 70 between two adjacent tabs is reduced to further improve the sealing performance of the top seal package 70.

[0050] like Figure 1 As shown, Figure 1 The portion corresponding to the middle shoulder seal area is the top seal package 70 portion corresponding to the first shoulder 32. Figure 1 The portion corresponding to the middle positive electrode sealing area is the top seal package 70 portion corresponding to the first positive electrode portion 31. Figure 1 The portion corresponding to the middle negative electrode seal area is the portion of the top seal package 70 corresponding to the first negative electrode portion 33. The thickness of the top seal package 70 corresponding to the first shoulder portion 32 can be understood as the average thickness of the portion corresponding to the shoulder seal area. Similarly, the thickness of the top seal package 70 corresponding to the first positive electrode portion 31 can be understood as the average thickness of the portion corresponding to the positive electrode seal area, and the thickness of the top seal package 70 corresponding to the first negative electrode portion 33 can be understood as the average thickness of the portion corresponding to the negative electrode seal area.

[0051] Taking the case where there are two tabs as an example, in this example, the two tabs are a positive tab 10 and a negative tab 20, respectively. The positive tab 10 is located between the first positive electrode portion 31 and the second positive electrode portion 41, and the negative tab 20 is located between the first negative electrode portion 33 and the second negative electrode portion 43. The aforementioned wavy top seal package 70 can, on the one hand, prevent the top seal package 70 from having an excessively thick adhesive layer (referring to a polypropylene layer) in the portion between the two adjacent tabs. On the other hand, it can also reduce the probability of the tabs being affected by the aforementioned welds and being damaged in the event of tab misalignment. Tab misalignment can be understood as a situation where the positive tab 10 is partially or completely located between the first shoulder 32 and the second shoulder 42, or where the negative tab 20 is partially or completely located between the first shoulder 32 and the second shoulder 42.

[0052] Optionally, the first shoulder 32 includes a first wave crest and a first wave trough, and the second shoulder 42 includes a second wave crest and a second wave trough;

[0053] A thickness difference between the first corrugation peak and the first corrugation valley is greater than a thickness difference between the second corrugation peak and the second corrugation valley.

[0054] Through the above arrangement, under the premise of ensuring the sealing performance of the top seal package 70 portion corresponding to the first shoulder 32, the thickness adaptability of the top seal package 70 portion corresponding to the first shoulder 32 is increased, so as to further reduce the probability of the tab being affected by the aforementioned welding parts and being damaged when the tab is misaligned.

[0055] A ratio of a thickness difference between the second wave crest and the second wave trough to a thickness difference between the first wave crest and the first wave trough is greater than or equal to 0.45 and less than or equal to 0.55.

[0056] For example, the ultrasonic welding seat 92 may include three parts, a positive electrode seat 93, a shoulder seat 94 and a negative electrode seat 95, which are connected in sequence. The structural parameters of the teeth (and gaps) of the positive electrode seat 93 and the negative electrode seat 95 are shown in the above example (referring to Figure 5 In the structure shown, the teeth and the gap portions are both in the form of a first trapezoid, and the first side length a of the first trapezoid is between 80 microns and 200 microns; the second side length b of the first trapezoid is between 100 microns and 200 microns; the height h of the first trapezoid is between 20 microns and 60 microns). The structural parameters of the teeth (and gap portions) of the ultrasonic welding head 91 are the same as the structural parameters of the teeth (and gap portions) of the positive electrode seat 93, and will not be repeated here. The ratio of the structural parameters of the teeth (and gap portions) of the shoulder seat 94 to the structural parameters of the teeth (and gap portions) of the positive electrode seat 93 is greater than or equal to 0.45 and less than or equal to 0.55. For example, the teeth of the shoulder seat 94 are in the form of a second trapezoid, and the first side length a' of the second trapezoid is between 36 microns and 110 microns.

[0057] As mentioned above, by adjusting the structure of the ultrasonic welding seat 92 and the ultrasonic welding head 91, the ratio of the thickness difference between the second wave peak and the second wave valley to the thickness difference between the first wave peak and the first wave valley can be controlled in the range of 0.45 to 0.55, so as to reduce the probability of the tab being affected by the aforementioned welding parts and being damaged when the tab is misaligned.

[0058] Optionally, the thickness difference between the first wave crest and the first wave valley is greater than or equal to 20 microns and less than or equal to 60 microns.

[0059] As mentioned above, the thickness difference between the first wave crest and the first wave trough is the height h corresponding to the tooth portion (or gap portion) of the positive electrode seat 93. By controlling the thickness difference between the first wave crest and the first wave trough, on the one hand, the problem of poor structural stability of the top seal package 70 caused by excessive thickness difference can be avoided. On the other hand, the role of the wave-shaped setting in reducing the difficulty of the process can be fully utilized.

[0060] Optionally, the top seal package 70 corresponding to the first shoulder 32 includes a first package high portion and a first package low portion, and the thickness of the first package high portion is greater than or equal to 285 microns and less than or equal to 315 microns.

[0061] Optionally, the thickness of the lower portion of the first package is greater than or equal to 255 microns and less than or equal to 285 microns.

[0062] like Figure 1As shown, the thickness of the first package high portion can be understood as the thickness between the thickest point of the first shoulder 32 and the thickest point of the second shoulder 42 (i.e., the thickness between the first wave peak and the second wave peak). By controlling the thickness of the first package high portion, the top seal package 70 can still maintain better sealing performance and structural stability while reducing the process difficulty of the top seal package 70.

[0063] Optionally, the tabs include a positive tab 10 and a negative tab 20, and the positive tab 10 and the negative tab 20 are located on the same side of the battery cell;

[0064] The positive electrode tab 10 is located between the first positive electrode portion 31 and the second positive electrode portion 41 , and the negative electrode tab 20 is located between the first negative electrode portion 33 and the second negative electrode portion 43 .

[0065] Optionally, the top seal package 70 corresponding to the first positive electrode portion 31 includes a second package high portion and a second package low portion, and the thickness of the second package low portion is smaller than the thickness of the second package high portion.

[0066] Furthermore, the thickness of the second package lower portion is greater than or equal to 765 micrometers and less than or equal to 815 micrometers; the thickness of the second package upper portion is greater than or equal to 835 micrometers and less than or equal to 885 micrometers.

[0067] like Figure 1 As shown, the thickness of the second package high part can be understood as the thickness between the thickest point of the first positive electrode part 31 and the thickest point of the second positive electrode part 41, and the thickness of the second package low part can be understood as the thickness between the thinnest point of the first positive electrode part 31 and the thinnest point of the second positive electrode part 41. By controlling the thickness of the second package high part and the second package low part, the top seal package 70 can still maintain better sealing performance and structural stability while reducing the process difficulty of the top seal package 70.

[0068] Optionally, the top seal package 70 corresponding to the first negative electrode portion 33 includes a third package high portion and a third package low portion, and the thickness of the third package low portion is smaller than the thickness of the third package high portion.

[0069] Furthermore, the thickness of the third package lower portion is greater than or equal to 565 micrometers and less than or equal to 615 micrometers; the thickness of the third package upper portion is greater than or equal to 635 micrometers and less than or equal to 685 micrometers.

[0070] like Figure 1As shown, the thickness of the third package high part can be understood as the thickness between the thickest point of the first negative electrode part 33 and the thickest point of the second negative electrode, and the thickness of the third package low part can be understood as the thickness between the thinnest point of the first negative electrode part 33 and the thinnest point of the second negative electrode part 43. By controlling the thickness of the third package high part and the third package low part, the top seal package 70 can still maintain better sealing performance and structural stability while reducing the process difficulty of the top seal package 70.

[0071] The embodiments of the present application are described above in conjunction with the accompanying drawings, but the present application is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of this application, ordinary technicians in this field can also make many forms without departing from the purpose of this application and the scope of protection of the claims, all of which are within the protection of this application.

Claims

1. A battery, characterized in that: include: A first sealing film, a second sealing film, and a battery cell, wherein the first sealing film and the second sealing film cooperate to form a cavity, the battery cell is located in the cavity, the connection between the first sealing film and the second sealing film forms a top seal package, and the tab of the battery cell passes through the top seal package; The top seal package includes a first top seal film and a second top seal film, the tab is located between the first top seal film and the second top seal film, and the shapes of the first top seal film and the second top seal film are both wavy; The first top seal film includes a first positive electrode portion, a first shoulder portion and a first negative electrode portion connected in sequence; The second top seal film includes a second positive electrode portion, a second shoulder portion and a second negative electrode portion connected in sequence; The first positive electrode portion and the second positive electrode portion are opposite to each other, the first negative electrode portion and the second negative electrode portion are opposite to each other, and the first shoulder portion and the second shoulder portion are bonded to each other; The thickness of the top seal package corresponding to the first shoulder is smaller than the thickness of the top seal package corresponding to the first positive electrode portion, and the thickness of the top seal package corresponding to the first shoulder is smaller than the thickness of the top seal package corresponding to the first negative electrode portion; The first shoulder includes a first wave crest and a first wave valley, and the second shoulder includes a second wave crest and a second wave valley; the ratio of the thickness difference between the second wave crest and the second wave valley to the thickness difference between the first wave crest and the first wave valley is greater than or equal to 0.45 and less than or equal to 0.

55.

2. The battery according to claim 1, characterized in that A thickness difference between the first wave crest and the first wave valley is greater than or equal to 20 micrometers and less than or equal to 60 micrometers.

3. The battery according to claim 2, characterized in that The top seal package corresponding to the first shoulder portion includes a first package high portion and a first package low portion, and a thickness of the first package high portion is greater than or equal to 285 micrometers and less than or equal to 315 micrometers.

4. The battery according to claim 3, characterized in that The thickness of the first package lower portion is greater than or equal to 255 micrometers and less than or equal to 285 micrometers.

5. The battery according to claim 1, characterized in that The tabs include a positive tab and a negative tab, and the positive tab and the negative tab are located on the same side of the battery cell; The positive electrode tab is located between the first positive electrode portion and the second positive electrode portion, and the negative electrode tab is located between the first negative electrode portion and the second negative electrode portion.

6. The battery according to claim 5, characterized in that The top seal package corresponding to the first positive electrode portion includes a second package high portion and a second package low portion, and the thickness of the second package low portion is smaller than the thickness of the second package high portion.

7. The battery according to claim 6, characterized in that The thickness of the second package lower portion is greater than or equal to 765 micrometers and less than or equal to 815 micrometers; the thickness of the second package upper portion is greater than or equal to 835 micrometers and less than or equal to 885 micrometers.

8. The battery according to claim 5, characterized in that The top seal package corresponding to the first negative electrode portion includes a third package high portion and a third package low portion, and a thickness of the third package low portion is smaller than a thickness of the third package high portion.

9. The battery according to claim 8, characterized in that The thickness of the third package lower portion is greater than or equal to 565 micrometers and less than or equal to 615 micrometers; the thickness of the third package upper portion is greater than or equal to 635 micrometers and less than or equal to 685 micrometers.

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