Battery assembly and battery

Abstract

The utility model relates to the technical field of batteries, and discloses a battery assembly and a battery, and the battery assembly comprises a cover plate, lower plastic cement, an end plate and a stopper. The lower plastic is arranged on the inner side wall of the cover plate; the end plate is arranged on the inner side wall of the lower plastic; the end plate is provided with an inwards-concave containing groove. The stop piece is made of a high-temperature-resistant electrolyte-resistant material; the stop piece is arranged in the accommodating groove; a jacking part is arranged on one side, facing the cover plate, of the stop piece; and when the battery is in thermal runaway, the stop piece is suitable for abutting between the cover plate and the battery pole group, and the ejection part is suitable for ejecting the pressure relief structure. According to the battery assembly with the structure, when thermal runaway occurs in the battery, the stop piece is propped between the pole group and the cover plate, so that the pole group is prevented from moving to the cover plate to shield the pressure relief structure on the cover plate; when the pressure relief structure is slightly opened or is not opened, the stopping piece moves to the position below the pressure relief structure, the pressure relief structure is ejected by the ejection part, and the opening degree of the pressure relief structure is guaranteed, so that the exhaust efficiency is effectively guaranteed, and the safety of the battery is guaranteed.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, in particular to a battery assembly and a battery. Background Art

[0002] Lithium-ion batteries include cover, shell, pole group, end plate, side plate, bare cell insulation sheet, pole group, electrolyte and other components. The cover is integrated with an explosion-proof valve, and the side plate, bare cell insulation sheet, end plate and lower plastic constitute the insulation protection structure of the pole group, so that the battery cell can avoid short circuit and other problems caused by overlapping the pole group with the shell or cover during normal use.

[0003] The insulating protection structures of the electrode groups are all made of plastic and have poor high-temperature resistance. When the battery is in thermal runaway, its internal temperature rises rapidly, and the insulating protection structures such as the side panels, bare cell insulating sheets, end panels, and lower plastic will quickly melt and fail. At this time, there is only the electrode group inside the shell, and there is no obstruction between the electrode group and the cover. Under the action of high-temperature and high-pressure gas inside the shell, the electrode group will lose balance. Because the pressure at the explosion-proof valve of the cover is relatively low, the electrode group can easily move toward the explosion-proof valve, thereby blocking the explosion-proof valve, causing the explosion-proof valve to fail to open, and the battery cannot be depressurized in time, causing fire and explosion. Utility Model Content

[0004] In view of this, the utility model provides a battery assembly and a battery to solve the problem in the prior art that the explosion-proof valve cannot be opened due to the pole group blocking the explosion-proof valve when the battery is thermally runaway.

[0005] In a first aspect, the utility model provides a battery assembly, comprising:

[0006] A cover plate, on which a pressure relief hole and a pressure relief structure are provided;

[0007] A lower plastic, arranged on the inner side wall of the cover plate;

[0008] An end plate is arranged on the inner side wall of the lower plastic; the end plate is provided with a concave receiving groove;

[0009] The stopper is made of a high temperature resistant and electrolyte resistant material; the stopper is arranged in the receiving groove; the stopper is provided with an opening portion on the side facing the cover plate; when the battery thermally runs away, the stopper is suitable for abutting between the cover plate and the battery pole group, and the opening portion is suitable for opening the pressure relief structure.

[0010] Beneficial effect: A battery assembly of this structure is provided with a stopper on the end plate. The battery assembly is used in a battery. The battery assembly is mounted on a battery shell, and a pole group is arranged in the shell. When the battery has thermal runaway and the temperature inside the shell rises rapidly, the lower plastic and the end plate melt and fail at high temperature. Since the stopper is resistant to high temperature, the stopper can still maintain its original shape and strength at high temperature. The pole group moves toward the cover plate and the pressure relief structure under the action of the high temperature and high pressure gas inside the shell. The stopper is arranged between the cover plate and the pole group. The pole group first contacts the stopper and then drives the stopper to move toward the cover plate. The stopper abuts between the pole group and the cover plate to prevent the pole group from moving to the cover plate and blocking the pressure relief structure on the cover plate. During thermal runaway, the stopper will move horizontally a short distance along the length direction of the cover plate. The stopper is arranged near the pressure relief structure, and the horizontal distance from the stopper to the pressure relief structure is sufficient to allow it to move below the pressure relief structure during thermal runaway. When the pressure relief structure is opened slightly or not opened, the stopper moves to the bottom of the pressure relief structure, and the opening portion opens the pressure relief structure to ensure the opening degree of the pressure relief structure, so as to effectively ensure the exhaust efficiency and ensure the safety of the battery.

[0011] In an optional embodiment, the stopper is located within a projection area of ​​the pressure relief structure on the end plate.

[0012] Beneficial effect: When the battery thermally runs away, under the action of the internal air pressure and the push of the electrode group, the stopper moves directly upward toward the bottom of the pressure relief structure. Under the action of the high-pressure airflow inside the shell, the top opening part pushes open the pressure relief structure, which can effectively ensure that the top opening part contacts the pressure relief structure, thereby ensuring the opening effect of the top opening part on the pressure relief structure.

[0013] In an optional embodiment, a side of the top opening facing the cover plate is provided with an edge structure or a spike structure.

[0014] Beneficial effect: It is easy to puncture the pressure relief structure through the edge structure or the spike structure to ensure the opening degree of the pressure relief structure, so as to ensure the pressure relief effect of the battery.

[0015] In an optional embodiment, the top opening portion is in the shape of an elongated strip.

[0016] Beneficial effect: When the stopper contacts the pressure relief structure, the contact area with the pressure relief structure is small, and the pressure on the pressure relief structure is strong so that the pressure relief structure can be quickly pushed open, thereby improving the pressure relief efficiency and ensuring the pressure relief effect.

[0017] In an optional implementation, the length of the top opening is A, the width of the notch of the pressure relief structure is B, and 0.3B≤A≤0.7B.

[0018] Beneficial effect: The width of the top opening and the notch of the pressure relief structure satisfies 0.3B≤A≤0.7B, so that the top opening can be completely located inside the notch of the pressure relief structure, so that the top opening can effectively push open the notch area of ​​the pressure relief structure under the action of air pressure.

[0019] In an optional implementation, the stopper is in the shape of a rectangular block, the length of the stopper is C, the width of the pressure relief hole is F, and C≥1.1F or C≥F+2.

[0020] Beneficial effects: preventing the stopper from flying out of the pressure relief hole under the action of high-pressure airflow, thereby ensuring safety; at the same time, ensuring that there is sufficient contact area between the stopper and the pressure relief mechanism, thereby preventing the stopper from being crushed and damaged under the action of high pressure.

[0021] In an optional embodiment, the width of the end plate is D, C≤0.9D or C≤D-1.

[0022] Beneficial effects: It is convenient to assemble the stopper in the receiving groove, while ensuring the wall thickness of the receiving groove and the overall strength of the end plate.

[0023] In an optional embodiment, the width of the stopper is E, and E≥4 mm.

[0024] Beneficial effect: The width of the stopper cannot be too small to ensure its blocking effect between the cover plate and the pole group, and prevent the pole group from tilting to one side and pressing the explosion-proof valve.

[0025] In an optional embodiment, the stopper is interference fit in the accommodating groove.

[0026] Beneficial effect: The stopper is easy and quick to assemble.

[0027] In a second aspect, the utility model further provides a battery, comprising any one of the battery components, shell and pole group described above, wherein the battery component is arranged at the opening of the shell, and the pole group is arranged inside the shell.

[0028] Beneficial effects: The battery shell has an opening, the cover is fixed on the opening, and the lower plastic and the end plate are arranged on the inner side of the cover in sequence. When the battery is in thermal runaway, the stopper abuts between the pole group and the cover to prevent the pole group from blocking the explosion-proof valve; during the thermal runaway process, when the explosion-proof notch is opened slightly or not opened, the push-opening part pushes open the explosion-proof valve to ensure the opening degree of the explosion-proof valve, so as to effectively ensure the exhaust efficiency and battery safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the specific implementation methods of the utility model or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0030] Figure 1 An exploded view of a battery assembly according to an embodiment of the utility model;

[0031] Figure 2 An exploded view of a battery assembly according to an embodiment of the utility model;

[0032] Figure 3 A top view of a battery assembly according to an embodiment of the utility model;

[0033] Figure 4 for Figure 3 AA section view;

[0034] Figure 5 for Figure 4 BB section view;

[0035] Figure 6 for Figure 1 A schematic diagram of the three-dimensional structure of the stop block;

[0036] Figure 7 It is a schematic diagram of the pressure relief structure in the figure;

[0037] Figure 8 for Figure 1 Schematic diagram of the middle cover;

[0038] Fig. 9 for Figure 1 Schematic diagram of the middle end cover.

[0039] Description of reference numerals:

[0040] 1. Cover plate; 101. Pressure relief hole; 2. Pressure relief structure; 3. Lower plastic; 4. End plate; 401. Accommodating groove; 5. Stopper; 501. Top opening. DETAILED DESCRIPTION

[0041] In order to make the purpose, technical solution and advantages of the embodiment of the utility model clearer, the technical solution in the embodiment of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiment of the utility model. Obviously, the described embodiment is a part of the embodiment of the utility model, not all the embodiments. Based on the embodiment of the utility model, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the utility model.

[0042] The existing insulating protection structures of the battery pole group, such as the side plates, bare cell insulating sheets, end plates 4, and lower plastic 3, are all made of plastic. When the battery thermally runs away, the insulating protection structure melts and fails at high temperature. A pressure relief structure 2 is provided on the cover plate 1. The pressure at the pressure relief structure 2 is relatively low. Under the action of the internal high-temperature and high-pressure gas, the pole group moves toward the pressure relief structure 2, thereby blocking the pressure relief structure 2 and affecting the normal opening of the pressure relief structure 2.

[0043] Combine the following Figures 1 to 9 , describing an embodiment of the utility model.

[0044] According to an embodiment of the present utility model, on the one hand, a battery assembly is provided, such as Figures 1 to 5 As shown, it includes a cover plate 1, a lower plastic 3, an end plate 4 and a stopper 5.

[0045] Among them, the cover plate 1 is provided with a pressure relief hole 101 and a pressure relief structure 2; the lower plastic 3 is arranged on the inner wall of the cover plate 1; the end plate 4 is arranged on the inner wall of the lower plastic 3; the end plate 4 is provided with a concave receiving groove 401; the material of the stopper 5 is high temperature resistant and electrolyte resistant; the stopper 5 is arranged in the receiving groove 401; the side of the stopper 5 facing the cover plate 1 is provided with a top opening portion 501; when the battery is thermally runaway, the stopper 5 is suitable for abutting between the cover plate 1 and the battery pole group, and the top opening portion 501 is suitable for opening the pressure relief structure 2.

[0046] In the battery assembly of this structure, a stopper 5 is arranged on the end plate 4. The battery assembly is applied in the battery. The battery assembly is mounted on the shell of the battery. A pole group is arranged in the shell. When the battery has thermal runaway and the temperature inside the shell rises rapidly, the lower plastic 3 and the end plate 4 melt and fail at high temperature. Since the stopper 5 is resistant to high temperature, the stopper 5 can still maintain its original shape and strength at high temperature. The pole group moves toward the cover plate 1 and the pressure relief structure 2 under the action of the high temperature and high pressure gas inside the shell. The stopper 5 is arranged between the cover plate 1 and the pole group. The pole group first contacts the stopper 5 and then drives the stopper 5 to move toward the cover plate 1. The stopper 5 abuts between the pole group and the cover plate 1 to prevent the pole group from moving to the cover plate 1 to cover the pressure relief structure 2 on the cover plate 1. During the thermal runaway process, the stopper 5 will move horizontally for a short distance along the length direction of the cover plate 1. The stopper 5 is arranged near the pressure relief structure 2. The horizontal distance from the stopper 5 to the pressure relief structure 2 is sufficient to allow it to move below the pressure relief structure 2 during thermal runaway. When the pressure relief structure 2 is opened slightly or not opened, the stopper 5 moves to the bottom of the pressure relief structure 2, and the opening portion 501 opens the pressure relief structure 2 to ensure the opening degree of the pressure relief structure 2, so as to effectively ensure the exhaust efficiency and the battery safety.

[0047] Optionally, in one embodiment, the stopper 5 is located in the projection area of ​​the pressure relief structure 2 on the end plate 4, that is, Figure 4As shown, the stopper 5 is located at the lower side of the pressure relief structure 2. When the battery thermally runs away, under the action of the internal air pressure and the push of the electrode group, the stopper 5 moves directly upward toward the bottom of the pressure relief structure 2. Under the action of the high-pressure airflow inside the shell, the opening portion 501 opens the pressure relief structure 2, which can effectively ensure that the opening portion 501 contacts the pressure relief structure 2, thereby ensuring the opening effect of the opening portion 501 on the pressure relief structure 2.

[0048] In other embodiments, the stopper 5 may also be located on the left or right side of the projection area of ​​the pressure relief structure 2 on the end plate 4, and the horizontal distance from the stopper 5 to the pressure relief structure 2 is sufficient to ensure that when the battery thermally runs away, the stopper 5 can move to the bottom of the pressure relief structure 2 and make the opening portion 501 contact and push open the pressure relief structure 2.

[0049] Alternatively, if Figure 6 As shown, the top opening 501 is provided with an edge structure or a spike structure on one side facing the cover plate 1, so as to facilitate piercing the pressure relief structure 2 through the edge structure or the spike structure, thereby ensuring the opening degree of the pressure relief structure 2 and ensuring the pressure relief effect of the battery.

[0050] For example, Figure 6 As shown, in one embodiment, the longitudinal section of the top opening 501 is trapezoidal, or in other embodiments, the top opening 501 is a pointed cone structure with a triangular longitudinal section.

[0051] like Figure 6 As shown, in one embodiment, the opening portion 501 is in the shape of an elongated strip, and when it contacts the pressure relief structure 2, the contact area with the pressure relief structure 2 is small. The pressure exerted on the pressure relief structure 2 is strong so as to quickly open the pressure relief structure 2, thereby improving the pressure relief efficiency and ensuring the pressure relief effect.

[0052] Optionally, the push-up portion 501 extends along the length direction of the stopper 5 , and the push-up portion 501 is located in the middle of a side of the stopper 5 facing the cover plate 1 .

[0053] Preferably, in one embodiment, Figure 6 and Figure 7 As shown, the length of the top opening 501 is A, the width of the notch of the pressure relief structure 2 is B, and 0.3B≤A≤0.7B. The top opening 501 moves to the bottom of the pressure relief structure 2, and the top opening 501 extends along the width direction of the notch of the pressure relief structure 2. The top opening 501 and the width of the notch of the pressure relief structure 2 satisfy 0.3B≤A≤0.7B, that is, the length of the top opening 501 is less than the width of the notch of the pressure relief structure 2, so that the top opening 501 can be completely located inside the notch of the pressure relief structure 2, so that the top opening 501 can effectively push open the notch area of ​​the pressure relief structure 2 under the action of air pressure.

[0054] like Figure 6 and Figure 8As shown, the stopper 5 is in the shape of a rectangular block, the length of the stopper 5 is C, the width of the pressure relief hole 101 is F, C≥1.1F or C≥F+2. The notched area of ​​the pressure relief structure 2 is located within the pressure relief hole 101 of the cover plate 1, and the area outside the notch of the pressure relief structure 2 abuts and is fixed on the cover plate 1. The long side of the stopper 5 extends along the width direction of the notched area. When the battery is thermally runaway, the two ends of the long side of the stopper 5 abut on both sides of the width direction of the pressure relief mechanism, C≥1.1F or C≥F+2, that is, the length of the stopper 5 is greater than the pressure relief hole 101 and the notch width, preventing the stopper 5 from flying out of the pressure relief hole 101 under the action of high-pressure airflow, ensuring safety; at the same time, C≥1.1F or C≥F+2 can ensure that there is enough contact area between the stopper 5 and the pressure relief mechanism to prevent the stopper 5 from being crushed and damaged under the action of high pressure.

[0055] Optionally, in one embodiment, the cover plate 1 is a rectangular cover plate 1, and correspondingly, the lower plastic 3 and the end plate 4 are both rectangular. The pressure relief hole 101 is in the shape of a waist hole, and the pressure relief structure 2 is an explosion-proof valve, which is provided with explosion-proof notches, and the explosion-proof valve is fixed on the inner side wall of the cover plate 1. The cover plate 1 is also provided with a pole.

[0056] In other embodiments, the cover plate 1 may also be a circular cover plate 1, and the corresponding battery assembly is used in a cylindrical battery.

[0057] like Fig. 9 As shown, in one embodiment, the width of the end plate 4 is D, C≤0.9D or C≤D-1, and the length of the stop member 5 is smaller than the width of the end plate 4 and satisfies this dimensional relationship, so that the stop member 5 can be assembled in the receiving groove 401 while ensuring the wall thickness of the receiving groove 401 and the overall strength of the end plate 4.

[0058] like Figure 6 As shown, in one embodiment, the width of the stopper 5 is E, E≥4mm, and the width of the stopper 5 cannot be too small to ensure its blocking effect between the cover plate 1 and the pole group to prevent the pole group from tilting to one side and pressing the explosion-proof valve.

[0059] In the present invention, the length A of the top opening 501 , the notch width B of the pressure relief structure 2 , the length C of the stopper 5 , the width D of the end plate 4 and the width F of the pressure relief hole 101 are all measured in millimeters.

[0060] Optionally, in one embodiment, the stopper 5 is interference-fitted in the receiving groove 401. The assembly of the stopper 5 is simple, fast and efficient. Figure 6 As shown, interference ribs are respectively arranged on the surrounding side walls of the stopper 5 , and at least two interference ribs are arranged on each side wall of the stopper 5 .

[0061] In other embodiments, interference ribs may be provided on the inner wall of the receiving groove 401 ; and the stop block may be bonded or integrally injection molded on the end plate 4 .

[0062] Optionally, the stopper 5 is made of any material that is resistant to high temperatures and electrolytes, such as ceramics or aluminum alloy.

[0063] According to an embodiment of the present invention, on the other hand, a battery is provided, comprising the above-mentioned battery assembly, a shell and a pole group, wherein the battery assembly is arranged at the opening of the shell, and the pole group is arranged inside the shell.

[0064] The battery housing has an opening, the cover plate 1 is fixed on the opening, and the lower plastic 3 and the end plate 4 are sequentially arranged on the inner side of the cover plate 1. When the battery is in thermal runaway, the stopper 5 abuts between the pole group and the cover plate 1 to prevent the pole group from blocking the explosion-proof valve; during the thermal runaway process, when the explosion-proof notch is opened slightly or not opened, the push-opening part 501 pushes the explosion-proof valve to ensure the opening degree of the explosion-proof valve, so as to effectively ensure the exhaust efficiency and the battery safety.

[0065] Although the embodiments of the present invention are described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A battery assembly, It is characterized in that include: A cover plate, on which a pressure relief hole and a pressure relief structure are provided; A lower plastic, arranged on the inner side wall of the cover plate; An end plate is arranged on the inner side wall of the lower plastic; the end plate is provided with a concave receiving groove; The stopper is made of a high temperature resistant and electrolyte resistant material; the stopper is arranged in the receiving groove; the stopper is provided with an opening portion on the side facing the cover plate; when the battery thermally runs away, the stopper is suitable for abutting between the cover plate and the battery pole group, and the opening portion is suitable for opening the pressure relief structure.

2. The battery assembly according to claim 1, It is characterized in that The stopper is located within a projection area of ​​the pressure relief structure on the end plate.

3. The battery assembly according to claim 1 or 2, It is characterized in that The side of the top opening facing the cover plate is provided with an edge structure or a spike structure.

4. The battery assembly according to claim 1 or 2, It is characterized in that The top opening portion is in the shape of an elongated strip.

5. The battery assembly according to claim 4, It is characterized in that The length of the top opening is A, the width of the notch of the pressure relief structure is B, and 0.3B≤A≤0.7B.

6. The battery assembly according to claim 1 or 2, It is characterized in that The stopper is in a rectangular block shape, the length of the stopper is C, the width of the pressure relief hole is F, and C≥1.1F or C≥F+2.

7. The battery assembly according to claim 6, It is characterized in that The width of the end plate is D, C≤0.9D or C≤D-1.

8. The battery assembly according to claim 6, It is characterized in that The width of the stopper is E, E≥4mm.

9. The battery assembly according to claim 1 or 2, It is characterized in that The stopper is interference-fitted in the accommodating groove.

10. A battery, It is characterized in that It comprises the battery assembly, shell and pole group according to any one of claims 1 to 9, wherein the battery assembly is arranged at the opening of the shell, and the pole group is arranged inside the shell.

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