End cover assembly, energy storage device and electric equipment

Abstract

According to the end cover assembly, the energy storage device and the electric equipment, the overcurrent capacity of the end cover assembly is improved, and the energy efficiency and the product competitiveness of the energy storage device are improved. The end cover assembly comprises an end cover, a lower insulating part, a pin, a pole and an overcurrent sheet; the end cover is provided with a first pole hole, and the first pole hole penetrates through the end cover along the thickness direction of the end cover; the upper insulating part and the lower insulating part are located on one side of the end cover in the thickness direction of the end cover, the lower insulating part is provided with a second pole hole, and the second pole hole penetrates through the lower insulating part in the thickness direction of the lower insulating part and is communicated with the first pole hole; the pin is located on the side, away from the end cover, of the lower insulating part, the pin is provided with a third pole hole, and the third pole hole penetrates through the pin in the thickness direction of the pin and is communicated with the second pole hole; the pole penetrates through the first pole hole, the second pole hole and the third pole hole and is fixedly connected with the pin; and the over-current sheet is mounted on one side, deviating from the end cover, of the lower insulating part, and is fixedly connected with the pins and the pole columns.

Description

Technical Field

[0001] The present application relates to the field of energy storage technology, and in particular to an end cover assembly, an energy storage device, and an electrical equipment. Background Art

[0002] As energy storage devices become increasingly widely used, people are placing higher demands on their energy density, performance, reliability, and cost. In existing energy storage devices, the current flow path from the cell assembly to the battery plate has poor current flow capacity from the pin to the terminal, resulting in low energy efficiency and reducing the competitiveness of energy storage devices. Summary of the Invention

[0003] The present application provides an end cover assembly, an energy storage device, and an electrical device, which increase the flow capacity of the end cover assembly and improve the energy efficiency and product competitiveness of the energy storage device.

[0004] The present application provides an end cap assembly, comprising an end cap, a lower insulating member, a pin, a pole and a current overflow plate;

[0005] The end cover is provided with a first pole hole, and the first pole hole penetrates the end cover along the thickness direction of the end cover;

[0006] The lower insulating member is located on one side of the end cover along the thickness direction of the end cover, and the lower insulating member is provided with a second pole hole, which passes through the lower insulating member along the thickness direction of the lower insulating member and is connected to the first pole hole;

[0007] The pin is located on a side of the lower insulating member away from the end cover, and the pin is provided with a third pole hole, the third pole hole passes through the pin along the thickness direction of the pin and is connected to the second pole hole;

[0008] The pole is passed through the first pole hole, the second pole hole and the third pole hole, and is fixedly connected to the pin;

[0009] The current-transmitting plate is installed on a side of the lower insulating member facing away from the end cover, and is fixedly connected to both the pin and the pole.

[0010] The pole includes a first surface, a second surface, and a first peripheral side surface. The first surface is located on the side of the end cover facing away from the lower insulating member. The second surface is located on the side of the lower insulating member facing away from the end cover and is disposed opposite to the first surface. The first peripheral side surface is connected between the first and second surfaces and is disposed opposite to the wall surface of the third pole hole.

[0011] The pole is provided with a first step groove, the first step groove is provided on the first peripheral side surface, the opening of the first step groove is located on the second surface, and the current-transmitting plate is installed in the first step groove.

[0012] In which, the pin is also provided with a second step groove, which is provided on the hole wall surface of the third pole hole and is arranged around the third pole hole. The opening of the second step groove is located on the surface of the pin away from the lower insulating member, and the current-transmitting plate is also installed in the second step groove.

[0013] The pole is further provided with a third step groove, which is provided on the first peripheral side surface, and the opening of the third step groove is located on the bottom wall surface of the first step groove.

[0014] The pin is further provided with a fourth step groove, which is provided on the hole wall surface of the third pole hole and surrounds the third pole hole. The opening of the fourth step groove is located on the bottom wall surface of the second step groove.

[0015] Wherein, the pin and the current-transmitting plate are integrally formed.

[0016] The pole is further provided with a clamping groove, the opening of which is located on the bottom wall of the second step groove, and the clamping groove is spaced apart from the first peripheral side surface;

[0017] The current-transmitting plate is provided with a clamping protrusion, which is provided on the surface of the current-transmitting plate facing the lower insulating member and is clamped in the clamping groove.

[0018] In which, the snap-fit protrusion includes a raised surface, a first side surface, a second side surface, a first chamfered surface and a second chamfered surface, the raised surface is the surface of the snap-fit protrusion facing the lower insulating member, the second side surface is located on the side of the first side surface away from the first peripheral side surface, and is arranged opposite to the first side surface, the first chamfered surface is connected between the raised surface and the first side surface, and the second chamfered surface is connected between the raised surface and the second side surface.

[0019] The area of the first surface is greater than the area of the second surface.

[0020] The present application also provides an energy storage device, which includes a shell, a battery cell assembly and the above-mentioned end cover assembly. The shell is provided with a receiving cavity and an opening. The receiving cavity is located on the inner side of the shell and contains electrolyte. The opening is located on the top side of the receiving cavity and is connected to the receiving cavity. The battery cell assembly is accommodated in the receiving cavity. The end cover assembly is installed on the shell, closes the opening, and is electrically connected to the battery cell assembly.

[0021] Wherein, the energy storage device further includes a bus bar, which is located on the side of the end cover away from the lower insulating member and is fixedly connected to the pole column.

[0022] The present application also provides an electrical device, including the above-mentioned energy storage device, and the energy storage device is used to supply power to the electrical device.

[0023] By adding an overcurrent piece in the present application and fixedly connecting the overcurrent piece to the pin and the pole column, the number of overcurrent channels from the pin to the pole column is increased, thereby improving the overcurrent capacity of the end cover assembly, and further improving the energy efficiency and product competitiveness of the energy storage device. At the same time, the total leakage probability at the welding joints among the pin, the overcurrent piece, and the pole column can also be reduced, enhancing the airtightness of the end cover assembly and improving the safety performance of the energy storage device. Description of the Drawings

[0024] In order to more clearly illustrate the technical solutions of the present application, the drawings required for the embodiments of the present application will be described below.

[0025] Figure 1 is a schematic structural diagram of the energy storage device provided by the present application;

[0026] Figure 2 is Figure 1 the exploded structural diagram of the energy storage device shown;

[0027] Figure 3 is Figure 2 the schematic structural diagram of the end cover assembly in the energy storage device shown in the first embodiment;

[0028] Figure 4 is Figure 3 the exploded structural diagram of the end cover assembly shown;

[0029] Figure 5 is Figure 2 the schematic cross-sectional structural diagram of the end cover assembly and the bus bar after being cut along A-A;

[0030] Figure 6 is Figure 5 the enlarged schematic diagram of area a in the end cover assembly shown;

[0031] Figure 7 is Figure 5 the enlarged schematic diagram of area b in the schematic cross-sectional structural diagram of the end cover assembly and the bus bar shown;

[0032] Figure 8 is Figure 5 the structural diagram of area b in the schematic cross-sectional structural diagram of the end cover assembly and the bus bar shown from another angle;

[0033] Figure 9 is Figure 4Schematic diagram of the structure of the shown pins sectioned along B-B;

[0034] Figure 10 is Figure 4 Schematic diagram of the structure of the shown overcurrent chip;

[0035] Figure 11 is Figure 3 Schematic diagram of the sectional structure of the shown end cap assembly sectioned along C-C in the second embodiment;

[0036] Figure 12 is Figure 11 Schematic diagram of the structure of the pins and overcurrent chip in the shown end cap assembly;

[0037] Figure 13 is Figure 12 Schematic diagram of the structure of the shown pins and overcurrent chip sectioned along D-D;

[0038] Figure 14 is Figure 3 Schematic diagram of the sectional structure of the shown end cap assembly sectioned along C-C in the third embodiment;

[0039] Figure 15 is Figure 14 Schematic diagram of the structure of the pins and overcurrent chip in the shown end cap assembly;

[0040] Figure 16 is Figure 15 Schematic diagram of the structure of the shown pins and overcurrent chip sectioned along E-E;

[0041] Figure 17 is Figure 14 Enlarged schematic diagram of area c in the shown end cap assembly.

[0042] Reference numerals: energy storage device 1000, housing 2000, battery cell assembly 3000, end cover assembly 4000, tab 5000, receiving cavity 2001, opening 2002, end cover 100, explosion-proof valve 200, protective sheet 300, lower insulating member 400, terminal post 500, pin 610, current-limiting sheet 620, upper insulating member 700, sealing ring 800, top patch 900, fifth surface 101, sixth surface 102, third circumferential side surface 103, explosion-proof hole 110, first terminal post hole 120, ventilation hole 410, second terminal post hole 420, first surface 501, second surface 502, first circumferential side surface 503, first step groove 510, third step groove 520, third groove bottom wall surface 511, third groove side wall surface 512, fourth groove bottom wall surface 521, fourth groove side wall surface 522, connecting portion 611, clamping portion 612, third surface 611a, fourth surface 611b, second circumferential side surface 611c, third terminal post hole 10, second step groove 20, fourth step groove 30, first groove bottom wall 21, first groove side wall 22, second groove bottom wall surface 31, second groove side wall surface 32, seventh surface 621, eighth surface 622, fourth circumferential side surface 623, first through hole 630, first welding position 1, second welding position 2, third welding position 3, second through hole 910, fourth terminal post hole 920, fourth welding position 4, fifth welding position 5, sixth welding position 6, clamping protrusion 40, protrusion surface 41, first side surface 42, second side surface 43, first chamfered surface 44, second chamfered surface 45, clamping groove 530, fifth groove bottom wall surface 531, fifth groove side wall surface 532, sixth groove side wall surface 533. Detailed implementation manners

[0043] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts shall fall within the protection scope of the present application.

[0044] Please refer to Figures 1 to 3 , Figure 1 which is a schematic structural diagram of the energy storage device 1000 provided by the present application, Figure 2 is Figure 1 a schematic exploded structural diagram of the energy storage device 1000 shown in Figure 3 is Figure 2 a schematic structural diagram of the end cover assembly 4000 in the energy storage device 1000 shown in the first embodiment.

[0045] The present application provides an energy storage device 1000, which may include but is not limited to single cells, battery modules, battery packs, battery systems, etc. The actual application forms of the energy storage device provided in the present application may be, but are not limited to, the listed products, and may also be other application forms. The present application does not strictly limit the application forms of the energy storage device 1000. The present application takes the energy storage device 1000 as a square battery as an example for illustration.

[0046] The energy storage device 1000 includes a housing 2000, a battery cell assembly 3000, an end cover assembly 4000, and a tab 5000. The housing 2000 is provided with a receiving cavity 2001 and an opening 2002. The receiving cavity 2001 is located inside the housing 2000 and houses an electrolyte. The opening 2002 is located on the top side of the receiving cavity 2001 and communicates with the receiving cavity 2001. Among them, the housing 2000 can be made of aluminum. For example, the housing 2000 can be an aluminum shell. The battery cell assembly is received in the receiving cavity. The battery cell assembly can be immersed in the electrolyte. The end cover assembly 4000 is installed on the housing 2000, closes the opening 2002, and is electrically connected to the battery cell assembly 3000. The tab 5000 is connected to the end cover assembly 4000 and is used to connect to another energy storage device 1000.

[0047] Please refer to Figures 4 to 7 , Figure 4 which Figure 3 is the exploded structural schematic diagram of the end cover assembly 4000 shown in Figure 5 which Figure 2 is the cross-sectional structural schematic diagram of the end cover assembly 4000 and the tab 5000 after being cut along A-A shown in Figure 6 which Figure 5 is the enlarged schematic diagram of area a in the end cover assembly 4000 shown in Figure 7 which Figure 5 is the enlarged schematic diagram of area b in the cross-sectional structural schematic diagram of the end cover assembly 4000 and the tab 5000 shown in

[0048] In this embodiment, the end cap assembly 4000 includes an end cap 100, an explosion-proof valve 200, a protection sheet 300, a lower insulating member 400, pins 610, a pole column 500, an overcurrent sheet 620, an upper insulating member 700, a sealing ring 800, and a top patch 900. The explosion-proof valve 200 and the protection sheet 300 are both installed on the end cap 100. In the thickness direction of the end cap assembly 4000, the lower insulating member 400 is installed on one side of the end cap 100. The pins 610 are located on the side of the lower insulating member 400 away from the end cap 100 and are electrically connected to the tabs of the battery cell assembly 3000. Among them, there are two pins 610. One pin 610 serves as the positive pin, and the other pin 610 serves as the negative pin. In the thickness direction of the end cap assembly 4000, the pole column 500 passes through the end cap 100, the lower insulating member 400, and the pins 610 and is connected to the pins 610. Among them, there are two pole columns 500. In the length direction of the end cap assembly 4000, the two pole columns 500 are arranged at intervals and are respectively connected to one pin 610. One pole column 500 is connected to the positive pin and serves as the positive pole column. The other pole column 500 is connected to the negative pin and serves as the negative pole column. The overcurrent sheet 620 is installed on the side of the lower insulating member 400 away from the end cap 100 and is fixedly connected to the pins 610 and the pole column 500. Among them, there are two overcurrent sheets 620, and each overcurrent sheet 620 is fixedly connected to one pin 610 and one pole column 500. One overcurrent sheet 620 is fixedly connected to the positive pin and the positive pole column, and the other overcurrent sheet 620 is fixedly connected to the negative pin and the negative pole column.

[0049] The upper insulating member 700 is installed between the pole column 500 and the end cap 100. Among them, there are two upper insulating members 700, and each upper insulating member 700 is installed between one pole column 500 and the end cap 100. One upper insulating member 700 serves as the positive insulating member and is installed between the positive pole column and the end cap 100. The other upper insulating member 700 serves as the negative insulating member and is installed between the negative pole column and the end cap 100. The sealing ring 800 is sleeved on the upper insulating member 700 and is clamped between the end cap 100 and the pins 610. Among them, there are two sealing rings 800, and each sealing ring 800 is sleeved on one upper insulating member 700 and is clamped between the end cap 100 and one pin 610. One sealing ring 800 serves as the positive sealing ring and is sleeved on the positive insulating member and is clamped between the end cap 100 and the positive connection piece. The other sealing ring 800 serves as the negative sealing ring and is sleeved on the negative insulating member and is clamped between the end cap 100 and the negative connection piece. The top patch 900 is located on the side of the end cap 100 away from the lower insulating member 400 and is pasted on the end cap 100.

[0050] Please continue to refer to Figure 4, in this embodiment, the end cover 100 can be a polished aluminum sheet made of aluminum. The end cover 100 includes a fifth surface 101, a sixth surface 102, and a third circumferential side surface 103. In the thickness direction of the end cover 100, the fifth surface 101 and the sixth surface 102 are arranged opposite to each other. The third circumferential side surface 103 is connected between the fifth surface 101 and the sixth surface 102.

[0051] The end cover 100 is provided with an explosion-proof hole 110 and a first pole hole 120. In the thickness direction of the end cover 100, both the explosion-proof hole 110 and the first pole hole 120 penetrate through the end cover 100. Specifically, both the explosion-proof hole 110 and the first pole hole 120 penetrate through the fifth surface 101 and the sixth surface 102. In the length direction of the end cover 100, the explosion-proof hole 110 is located in the middle of the end cover 100. The first pole hole 120 is arranged at an interval from the explosion-proof hole 110 for the pole 500 to pass through. Among them, there are two first pole holes 120. In the length direction of the end cover 100, the two first pole holes 120 are respectively located on opposite sides of the explosion-proof hole 110 and are both arranged with the explosion-proof hole 110. One first pole hole 120 is for the positive pole to pass through. The other first pole hole 120 is for the negative pole to pass through.

[0052] In the thickness direction of the end cover assembly 4000, the explosion-proof valve 200 covers the opening of the explosion-proof hole 110 on the sixth surface 102. The protection sheet 300 covers the opening of the explosion-proof hole 110 on the fifth surface 101 and protects the explosion-proof valve 200.

[0053] The lower insulating part 400 is located on the side of the sixth surface 102 away from the fifth surface 101. The lower insulating part 400 is provided with a ventilation hole 410 and a second pole hole 420. Both the ventilation hole 410 and the second pole hole 420 penetrate through the lower insulating part 400 along the thickness direction of the lower insulating part 400. In the length direction of the lower insulating part 400, the ventilation hole 410 is located in the middle of the lower insulating part 400 and is correspondingly arranged with the explosion-proof valve 200. It should be noted that the corresponding arrangement of the ventilation hole 410 and the explosion-proof valve 200 means that the positive projection of the explosion-proof valve 200 on the lower insulating part 400 will at least partially cover the ventilation hole 410.

[0054] The second pole hole 420 is located on one side of the ventilation hole 410 and is arranged at an interval from the ventilation hole 410. Among them, there are two second pole holes 420. In the length direction of the lower insulating part 400, the two second pole holes 420 are respectively located at opposite ends of the ventilation hole. Specifically, one second pole hole 420 is located on one side of the ventilation hole 410 and is communicated with one first pole hole 120 for the positive pole to pass through. The other second pole hole 420 is located on the other side of the ventilation hole 410 and is communicated with the other first pole hole 120 for the negative pole to pass through.

[0055] Please refer to Figure 8 andFigure 9 , Figure 8 is Figure 5 a schematic structural view of area b in another angle in the cross-sectional structural view of the end cap assembly 4000 and the tab 5000 shown, Figure 9 is Figure 4 a schematic structural view of the pin 610 shown cut along the B-B.

[0056] Each pin 610 is fixedly connected to one end of a pole 500. Each pin 610 includes a connecting portion 611 and a clamping portion 612. The connecting portion 611 is fixedly connected to the pole 500. Specifically, the connecting portion 611 includes a third surface 611a, a fourth surface 611b, and a second circumferential side surface 611c. The third surface 611a abuts against the lower insulating member 400 and has the same orientation as the fifth surface 101. In the thickness direction of the connecting portion 611, the fourth surface 611b is disposed opposite to the third surface 611a. The second circumferential side surface 611c is connected between the third surface 611a and the fourth surface 611b.

[0057] The connecting portion 611 is provided with a third pole hole 10, a second stepped groove 20, and a fourth stepped groove 30. In the thickness direction of the connecting portion 611, the third pole hole 10 penetrates through the third surface 611a and the fourth surface 611b, is spaced from the second circumferential side surface 611c, and communicates with the second pole hole 420.

[0058] The opening of the second stepped groove 20 is located on the surface of the pin 610 facing away from the lower insulating member 400, that is, on the fourth surface 611b. The second stepped groove 20 is provided on the hole wall surface of the third pole hole 10 and is recessed from the fourth surface 611b towards the third surface 611a. The second stepped groove 20 includes a first groove bottom wall 21 and a first groove side wall 22. The first groove bottom wall 21 is disposed opposite to the opening of the second stepped groove 20, is located between the third surface 611a and the fourth surface 611b, and is connected to the inner hole wall of the third pole hole 10. The first groove side wall 22 is connected between the first groove bottom wall 21 and the fourth surface 611b. Exemplarily, the second stepped groove 20 is annular and is disposed around the third pole hole 10.

[0059] The opening of the fourth stepped groove 30 is located on the first groove bottom wall surface 21. The fourth stepped groove 30 is provided on the hole wall surface of the third pole hole 10 and is recessed from the first groove bottom wall surface 21 towards the third surface 611a. The fourth stepped groove 30 includes a second groove bottom wall surface 31 and a second groove side wall surface 32. The second groove bottom wall surface 31 is disposed opposite to the opening of the fourth stepped groove 30 and is connected to the hole wall surface of the third pole hole 10. The second groove side wall surface 32 is connected between the second groove bottom wall surface 31 and the first groove bottom wall surface 21. Exemplarily, the fourth stepped groove 30 can be annular and is disposed around the third pole hole 10.

[0060] The clamping portion 612 is fixedly connected to one end of the connecting portion 611 away from the third pole hole. One end of the clamping portion 612 away from the connecting portion 611 is electrically connected to the tab of the battery cell assembly 3000. Exemplarily, the pin 610 is L-shaped, and the included angle between the clamping portion 612 and the connecting portion 611 is 90 degrees.

[0061] Please continue to refer to Figure 5 As shown in the figure, along the thickness direction of the end cover assembly 4000, each pole 500 passes through a first pole hole 120, a second pole hole 420, and a third pole hole 10. Each pole 500 includes a first surface 501, a second surface 502, and a first circumferential side surface 503. The first surface 501 is located on the side of the end cover 100 away from the lower insulating member 400 and faces the same direction as the fifth surface 101. The second surface 502 is located on the side of the lower insulating member 400 away from the end cover 100 and is opposite to the first surface 501. The first circumferential side surface 503 is connected between the first surface 501 and the second surface 502 and is relatively disposed with the hole wall surfaces of the first pole hole 120, the second pole hole 420, and the third pole hole 10.

[0062] In this embodiment, the area of the first surface 501 is larger than the area of the second surface 502. During the assembly process of the end cover assembly 4000, the pole 500 is assembled in a front-facing manner. That is, the pole 500 is installed from the end cover 100 towards the lower insulating member 400. Among them, the pole 500 will sequentially pass through the first pole hole 120 of the end cover 100, the second pole hole 420 of the lower insulating member 400, and the third pole hole 10 of the pin 610.

[0063] The pole 500 is provided with a first step groove 510 and a third step groove 520. The opening of the first step groove 510 is located on the second surface 502. The first step groove 510 is provided on the first circumferential side surface 503 and is recessed from the second surface 502 towards the first surface 501. The first step groove 510 includes a third groove bottom wall surface 511 and a third groove side wall surface 512. The third groove bottom wall surface 511 is opposite to the opening of the first step groove 510 and is located between the first surface 501 and the second surface 502. The third groove side wall surface 512 is connected between the third groove bottom wall surface 511 and the second surface 502. Exemplarily, the first step groove 510 is annular.

[0064] The opening of the third stepped groove 520 is located on the bottom wall surface 511 of the third groove. The third stepped groove 520 is provided on the first circumferential side surface 503, and is recessed from the bottom wall surface 511 of the third groove towards the first surface 501, and communicates with the first stepped groove 510. The third stepped groove 520 includes a fourth bottom wall surface 521 and a fourth side wall surface 522. The fourth bottom wall surface 521 is disposed opposite to the opening of the third stepped groove 520 and is connected to the first circumferential side surface 503. The fourth side wall surface 522 is connected between the fourth bottom wall surface 521 and the bottom wall surface 511 of the third groove. Exemplarily, the third stepped groove 520 is annular and surrounds the third pole hole 10.

[0065] Please continue to refer to Figure 8 and Figure 10 , Figure 10 is Figure 4 the structural schematic diagram of the current-carrying sheet 620 shown.

[0066] The current-carrying sheet 620 is installed in the second stepped groove 20 and the first stepped groove 510, and is fixedly connected to both the first side wall surface 22 of the pin 610 and the third side wall surface 512 of the pole 500. Specifically, the current-carrying sheet 620 includes a seventh surface 621, an eighth surface 622, and a fourth circumferential side surface 623. The seventh surface 621 is the surface of the current-carrying sheet 620 facing the lower insulating member 400. The seventh surface 621 is disposed opposite to the first bottom wall surface 21. Along the thickness direction of the current-carrying sheet 620, the eighth surface 622 is disposed opposite to the seventh surface 621. The fourth circumferential side surface 623 is connected between the seventh surface 621 and the eighth surface 622. The fourth circumferential side surface 623 faces the first side wall surface 22 and is fixedly connected to the first side wall surface 22.

[0067] The current-carrying sheet 620 is provided with a first through hole 630. The first through hole 630 penetrates the current-carrying sheet 620 along the thickness direction of the current-carrying sheet 620 and communicates with the third pole hole 10. The hole wall surface of the first through hole 630 is disposed opposite to the fourth circumferential side surface 623 and is fixedly connected to the third side wall surface 512 of the first stepped groove 510.

[0068] During the assembly process of the end cap assembly 4000, first, the hole wall surface of the third pole hole 10 and the first circumferential side surface 503 of the pole 500 are welded by means of seam welding to form a welding position 1, so as to realize the fixed connection between the pin 610 and the pole 500. It should be noted that since slag protrusions will be generated when welding the hole wall surface of the third pole hole 10 and the first circumferential side surface 503, the slag protrusions will be received in the third stepped groove 520 and the fourth stepped groove 30 to ensure that the slag protrusions do not protrude from the seventh surface 621 towards the eighth surface 622, and to prevent the slag protrusions from affecting the assembly between the current-carrying sheet 620 and the pin 610 and the pole 500.

[0069] After the current-carrying chip 620 is installed in the second step groove 20 and the first step groove 510, first, the fourth circumferential side surface 623 of the current-carrying chip 620 and the first groove side wall surface 22 of the second step groove 20 are welded by seam welding to form a second welding position 2, so as to realize the fixed connection between the current-carrying chip 620 and the pin 610. Finally, the hole wall surface of the first through hole 630 and the third groove side wall surface 512 of the first step groove 510 are welded by seam welding to form a third welding position 3, so as to realize the fixed connection between the current-carrying chip 620 and the terminal post 500.

[0070] In this embodiment, the current generated by the battery cell assembly 3000 can directly guide from the pin 610 to the terminal post 500 through the first welding position 1, or can first guide from the pin 610 to the current-carrying chip 620 through the second welding position 2, and then guide to the terminal post 500 through the third welding position 3. That is, there are two overcurrent channels for the current generated by the battery cell assembly 3000 from the pin 610 to the terminal post 500, which enhances the overcurrent capacity of the end cap assembly 4000 and improves the energy efficiency and product competitiveness of the energy storage device 1000.

[0071] In addition, assume that the air leakage probability of any welding position is a. That is, the air leakage ratios of the first welding position 1, the second welding position 2, and the third welding position 3 are all a. Then the probability that the first welding position 1 and the second welding position 2 leak air simultaneously is P1, P1 = a * a, and the probability that the first welding position 1 and the third welding position 3 leak air simultaneously is P2, P2 = a * a. In this embodiment, when the first welding position 1 and the second welding position 2 leak air simultaneously, or when the first welding position 1 and the third welding position 3 leak air simultaneously, the airtightness between the pin 610 and the terminal post 500 will fail. Therefore, the total air leakage probability between the pin 610, the current-carrying chip 620, and the terminal post 500 is P, P = P1 + P2 = 2 * a * a = 2a 2 . Under this setting, the total air leakage probability between the pin 610, the current-carrying chip 620, and the terminal post 500 can be greatly reduced, the airtightness of the end cap assembly 4000 is improved, and the safety performance of the energy storage device 1000 is ensured. Among them, the air leakage probability a of any welding position is about one ten-thousandth.

[0072] Please continue to refer to Figure 7, each upper insulating member 700 is disposed around a pole column 500 and passes through a first pole column hole 120 and a second pole column hole 420. Each sealing ring 800 is sleeved on an upper insulating member 700, passes through a first pole column hole 120 and a second pole column hole 420, and is clamped between the sixth surface 102 of the end cover 100 and the third surface 611a of a pin 610. The arrangement of the sealing ring 800 can not only seal the gap between the upper insulating member 700 and the lower insulating member 400 to ensure good airtightness of the end cover assembly 4000, but also insulate the end cover 100 from the pole column 500.

[0073] Please continue to refer to Figure 4 and Figure 8 , the top patch 900 is pasted on the fifth surface 101. The top patch 900 is provided with a second through hole 910 and a fourth pole column hole 920. Both the second through hole 910 and the fourth pole column hole 920 penetrate the top patch 900 along the thickness direction of the top patch 900. Along the length direction of the top patch 900, the second through hole 910 is located in the middle of the top patch 900 and exposes the protection sheet 300. The fourth pole column hole 920 is located on one side of the second through hole 910 and is spaced apart from the second through hole 910. Among them, there are two fourth pole column holes 920. The two fourth pole column holes 920 are respectively located on opposite sides of the second through hole 910 and are respectively communicated with a first pole column hole 120. Specifically, one fourth pole column hole 920 is communicated with a first pole column hole 120 for the positive pole column to pass through. The other fourth pole column hole 920 is communicated with the other first pole column hole 120 for the negative pole column to pass through.

[0074] Please continue to refer to Figure 5 and Figure 7 , one end of the bus bar 5000 in the energy storage device 1000 is fixedly connected to the first surface 501 of the pole column 500, and the other end of the bus bar 5000 is connected to another energy storage device 1000 to realize the parallel or series connection of multiple energy storage devices 1000.

[0075] Please refer to Figures 11 to 13 , Figure 11 is Figure 3 the schematic cross-sectional structure diagram of the end cover assembly 4000 shown in the second embodiment after being cut along C-C, Figure 12 is Figure 11 the schematic structure diagram of the pin 610 and the current-carrying sheet 620 in the end cover assembly 4000 shown, Figure 13 is Figure 12 the schematic structure diagram of the pin 610 and the current-carrying sheet 620 after being cut along D-D shown.

[0076] The difference between this embodiment and the first embodiment is that the fourth step groove 30 is not provided on the pin 610, the third step groove 520 is not provided on the pole column 500, and the pin 610 and the current-carrying piece 620 are integrally formed, which can reduce the number of parts of the energy storage device 1000. At the same time, the number of welding times for the assembly between the pin 610, the current-carrying piece 620 and the pole column 500 can be reduced, which is beneficial to improving the assembly efficiency and the airtightness of the energy storage device 1000.

[0077] During the assembly process of the end cover assembly 4000, first, the hole wall surface of the third pole column hole 10 and the first circumferential side surface 503 of the pole column 500 are welded by penetration welding to form the fourth welding position 4, so as to realize the fixed connection between the pin 610 and the pole column 500. Secondly, the seventh surface 621 and the first groove bottom wall surface 21 of the pole column 500 are welded by penetration welding to form the fifth welding position 5, so as to realize the fixed connection between the current-carrying piece 620 and the pole column 500. Finally, the hole wall surface of the first through hole 630 and the first groove side wall surface 22 of the pole column 500 are welded by slit welding to form the sixth welding position 6, further strengthening the connection between the current-carrying piece 620 and the pole column 500.

[0078] Preferably, any two of the fourth welding position 4, the fifth welding position 5 and the sixth welding position 6 are selected for welding, which can ensure enhanced current-carrying capacity while reducing the welding penetration depth, avoid the generation of welding pinholes and explosion points, and improve the airtightness and safety performance of the energy storage device 1000. At this time, there are two current-carrying channels from the pin 610 to the pole column 500. For example, when welding at the fourth welding position 4 and the fifth welding position 5, the current can directly pass from the pin 610 through the fourth welding position 4 to the pole column 500, or the current can pass from the pin 610 through the current-carrying piece 620 and then through the fifth welding position 5 to the pole column 500. Therefore, this embodiment can improve the current-carrying capacity between the pin 610 and the pole column 500, and improve the energy efficiency and product competitiveness of the energy storage device 1000. In addition, the two welding positions can reduce the total probability of air leakage between the pin 610, the current-carrying piece 620 and the pole column 500. At this time, the total probability of air leakage P between the pin 610, the current-carrying piece 620 and the pole column 500 is P = a * a = a 2 。

[0079] In some other embodiments, welding can be performed simultaneously at the fourth welding position 4, the fifth welding position 5, and the sixth welding position 6 to maximize the current-carrying capacity of the end cap assembly 4000 without increasing the diameter of the terminal post 500. Specifically, the current can flow from the pin 610 to the terminal post 500 through the fourth welding position 4, or the current can flow from the pin 610 through the current-carrying sheet 620 and then to the terminal post 500 through the fifth welding position 5 or the sixth welding position 6. At this time, there are three current-carrying channels from the pin 610 to the terminal post 500, which improves the current-carrying capacity between the pin 610 and the terminal post 500 and enhances the energy efficiency and product competitiveness of the energy storage device 1000. In addition, this embodiment can also reduce the total probability of air leakage between the pin 610, the current-carrying sheet 620, and the terminal post 500. Among them, the total probability of air leakage P between the pin 610, the current-carrying sheet 620, and the terminal post 500 is P = a * a * a = a 3 .

[0080] Please refer to Figures 14 to 16 , Figure 14 which Figure 3 is a schematic cross-sectional structure diagram of the end cap assembly 4000 shown after being cut along C-C in the third embodiment, Figure 15 and Figure 14 is a schematic structure diagram of the pin 610 and the current-carrying sheet 620 in the end cap assembly 4000 shown, Figure 16 and Figure 15 is a schematic structure diagram of the pin 610 and the current-carrying sheet 620 shown after being cut along E-E.

[0081] The difference between this embodiment and the second embodiment is that the terminal post 500 is further provided with a clamping groove 530, and the current-carrying sheet 620 is provided with a clamping protrusion 40, and the clamping protrusion 40 is installed in the clamping groove 530. Specifically, the opening of the clamping groove 530 is located on the bottom wall surface of the first step groove 510, that is, on the third bottom wall surface 511. The clamping groove 530 is recessed from the third bottom wall surface 511 towards the first surface 501. The clamping groove 530 includes a fifth bottom wall surface 531, a fifth groove side wall surface 532, and a sixth groove side wall surface 533. The fifth bottom wall surface 531 is opposite to the opening of the clamping groove 530 and is located between the third bottom wall surface 511 and the first surface 501. Both the fifth groove side wall surface 532 and the sixth groove side wall surface 533 are arranged around the third bottom wall surface 511. The fifth groove side wall surface 532 is connected between the third bottom wall surface 511 and the fifth bottom wall surface 531. The sixth groove side wall surface 533 is connected between the fifth bottom wall surface 531 and the third groove side wall surface 512.

[0082] Please refer to Figure 17 together with Figure 17 which Figure 14 is an enlarged schematic diagram of the area c in the end cap assembly 4000 shown.

[0083] The snap projection 40 is provided on the surface of the current-carrying sheet 620 facing the lower insulating member 400 and is snapped into the snap groove 530. Specifically, the snap projection 40 is provided on the seventh surface 621, protrudes from the seventh surface 621 towards the third surface 611a, and is located between the hole wall surface of the third pole hole 10 and the first circumferential side surface 503. The snap projection 40 includes a protruding surface 41, a first side surface 42, a second side surface 43, a first chamfered surface 44, and a second chamfered surface 45. The protruding surface 41 is the surface of the snap projection 40 facing the lower insulating member 400. The second side surface 43 is located on the side of the first side surface 42 away from the first circumferential side surface 503, is arranged opposite to the first side surface 42, and faces the pole 500. The first chamfered surface 44 is connected between the protruding surface 41 and the first side surface 42, and the included angle with the protruding surface 41 is an obtuse angle. The second chamfered surface 45 is connected between the protruding surface 41 and the second side surface 43, and the included angle with the protruding surface 41 is an obtuse angle. The design of the second chamfered surface 45 and the first chamfered surface 44 facilitates the insertion of the snap projection 40 into the snap groove 530 of the pole 500. Exemplarily, the snap projection 40 is annular and is arranged around the center of the pole 500.

[0084] In this embodiment, by providing the snap projection 40, the strength of the current-carrying sheet 620 is enhanced. At the same time, the snap projection 40 cooperates with the snap groove 530 to limit the snap projection 40 in the snap groove 530. When welding at the fourth welding position 4 and the fifth welding position 5, the degree of warping of the end of the current-carrying sheet 620 near the sixth welding position 6 due to excessive welding heat can be reduced, avoiding the influence of the welding process on the assembly stability between the current-carrying sheet 620 and the pole 500, further improving the assembly stability between the current-carrying sheet 620 and the pole 500, and improving the safety performance of the energy storage device 1000. In addition, when the end of the current-carrying sheet 620 near the sixth welding position 6 warps, since the snap projection 40 is limited in the snap groove 530, the snap projection 40 of the current-carrying sheet 620 will be in closer contact with the groove side wall and the groove bottom wall of the snap groove 530. Therefore, it is not necessary to weld at the sixth welding position 6, and a good current-carrying effect can be achieved through the close cooperation between the snap projection 40 and the snap groove 530, which helps to reduce the manufacturing cost of the energy storage device 1000.

[0085] In this application, by adding a current-carrying sheet 620 and fixedly connecting the current-carrying sheet 620 to the pin 610 and the pole 500, the number of current-carrying channels from the pin 610 to the pole 500 is increased, thereby improving the current-carrying capacity of the end cover assembly 4000, and thus improving the energy efficiency and product competitiveness of the energy storage device 1000. At the same time, the total leakage probability at the welding joints among the pin 610, the current-carrying sheet 620, and the pole 500 can also be reduced, enhancing the airtightness of the end cover assembly 4000 and improving the safety performance of the energy storage device 1000.

[0086] The present application further provides an electrical equipment, such as an energy storage cabinet, a new energy vehicle, etc. The electrical equipment includes the energy storage device 1000 in the above embodiments. Since the specific structure and technical effects of the energy storage device 1000 have been described in detail above, they will not be elaborated here. The electrical equipment provided in this embodiment improves the performance and use safety and reliability of the electrical equipment by providing the above energy storage device 1000.

[0087] The above are only the optional embodiments of the present application. The description of the above embodiments is only used to help understand the core idea of the present application, and does not limit the patent scope of the present application. At the same time, for those of ordinary skill in the art, according to the inventive concept of the present application, the equivalent structural transformations made by using the specification and drawings of the present application, or the direct / indirect application in other related technical fields all fall within the patent protection scope of the present application.

Claims

1. An end cap assembly, characterized in that, It includes an end cap, a lower insulating part, pins, a pole column and an overcurrent sheet; The end cap is provided with a first pole column hole which penetrates the end cap along the thickness direction of the end cap; Along the thickness direction of the end cap, the lower insulating part is located on one side of the end cap. The lower insulating part is provided with a second pole column hole which penetrates the lower insulating part along the thickness direction of the lower insulating part and is communicated with the first pole column hole; The pins are located on the side of the lower insulating part away from the end cap. The pins are provided with third pole column holes which penetrate the pins along the thickness direction of the pins and are communicated with the second pole column holes; The pole column is inserted into the first pole column hole, the second pole column hole and the third pole column hole and is fixedly connected with the pins; The overcurrent sheet is installed on the side of the lower insulating part away from the end cap and is fixedly connected with both the pins and the pole column; 2. The end cap assembly according to claim 1, wherein The pole column includes a first surface, a second surface and a first circumferential side surface. The first surface is located on the side of the end cap away from the lower insulating part. The second surface is located on the side of the lower insulating part away from the end cap and is arranged opposite to the first surface. The first circumferential side surface is connected between the first surface and the second surface and is arranged opposite to the wall surface of the third pole column hole; The pole column is provided with a first step groove which is arranged on the first circumferential side surface. The opening of the first step groove is located on the second surface. The overcurrent sheet is installed in the first step groove; 3. The end cap assembly according to claim 2, wherein, The pins are further provided with a second step groove which is arranged on the wall surface of the third pole column hole and surrounds the third pole column hole. The opening of the second step groove is located on the surface of the pins away from the lower insulating part. The overcurrent sheet is also installed in the second step groove; 4. The end cap assembly according to claim 3, characterized in that, The pole column is further provided with a third step groove which is arranged on the first circumferential side surface. The opening of the third step groove is located on the bottom wall surface of the first step groove; 5. The end cap assembly according to claim 3, characterized in that, The pins are further provided with a fourth step groove which is arranged on the wall surface of the third pole column hole and surrounds the third pole column hole. The opening of the fourth step groove is located on the bottom wall surface of the second step groove; 6. The end cap assembly according to claim 2, wherein, The pins and the overcurrent sheet are integrally formed; 7. The end cap assembly according to any one of claims 2 to 6, characterized in that, The pole column is further provided with a clamping groove. The opening of the clamping groove is located on the bottom wall surface of the second step groove. The clamping groove is arranged at an interval from the first circumferential side surface; The overcurrent sheet is provided with a clamping protrusion which is arranged on the surface of the overcurrent sheet facing the lower insulating part and is clamped in the clamping groove; 8. The end cap assembly according to claim 7, characterized in that, The clamping protrusion includes a protrusion surface, a first side surface, a second side surface, a first chamfered surface and a second chamfered surface. The protrusion surface is the surface of the clamping protrusion facing the lower insulating part. The second side surface is located on the side of the first side surface away from the first circumferential side surface and is arranged opposite to the first side surface. The first chamfered surface is connected between the protrusion surface and the first side surface. The second chamfered surface is connected between the protrusion surface and the second side surface; 9. The end cap assembly according to claim 2, wherein, The area of the first surface is larger than the area of the second surface.

10. An energy storage device, characterized in that, The energy storage device includes a shell, a battery cell assembly and an end cover assembly according to any one of claims 1 to 9, the shell is provided with a receiving cavity and an opening, the receiving cavity is located on the inner side of the shell and contains electrolyte, the opening is located on the top side of the receiving cavity and is connected to the receiving cavity, the battery cell assembly is received in the receiving cavity, the end cover assembly is installed on the shell, closes the opening, and is electrically connected to the battery cell assembly.

11. The energy storage device according to claim 10, characterized in that, The energy storage device further includes a tab, which is located on a side of the end cover away from the lower insulating member and is fixedly connected to the pole.

12. An electrical device, characterized in that, The energy storage device comprises the energy storage device according to claim 10 or 11, wherein the energy storage device is used to supply power to the electrical equipment.

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