Inner polarity poles, battery cells, and battery modules

Abstract

This invention relates to an inner pole post, a battery cell, and a battery module, and belongs to the field of new energy. The inner pole post includes a pole post body, at least one pole post connecting projection, and at least one pole post tab, the pole post tab and pole post connecting projection being fixed to both sides of the pole post body, respectively. The battery cell includes an inner pole post. The battery module includes a battery cell. This invention enables precise mounting, reduces the difficulty of positioning, and improves assembly efficiency.

Description

Technical Field

[0001] This application claims the priority of Chinese Patent Application No. 202310170501.3, titled "Inner Terminal, Battery Cell and Battery Module", filed with the China National Intellectual Property Administration on February 27, 2023, the entire content of which is incorporated herein by reference.

[0002] The present invention relates to the field of battery manufacturing, and more specifically, to inner terminals, battery cells and battery modules.

Background Art

[0003] A battery cell generally includes a case, a top cover of the battery, and a wound core (or called a cell stack). The wound core is disposed inside the case, has an upper end opening at the upper end of the case, and after the terminal on the top cover of the battery is connected to the current collector of the wound core, the wound core is disposed in the case, and the top cover of the battery is sealed to the opening at the upper end of the case by laser welding, and the terminal formed on the top cover of the battery can be electrically connected to external electronic components to supply power.

[0004] Currently, it is difficult to identify the mounting positions of the terminal and the top cover, and the wound core and the terminal, and the assembly difficulty of the battery cell is also high. When welding the top cover to the case, high precision is required for the assembly of the case and the top cover, resulting in high costs.

Summary of the Invention

Problems to be Solved by the Invention

[0005] The main object of this application is to provide an internal pole, a battery cell, and a battery module, which aims to solve one or more of the following technical problems in the prior art: a battery cell generally includes a case, a top cover of the battery, and a core (or cell stack), the core being placed inside the case and having an upper end opening at the top of the case, the pole on the top cover of the battery being connected to the current collector of the core, the core being placed inside the case, the top cover of the battery being sealed by laser welding at the opening at the top of the case, and the pole formed on the top cover of the battery being electrically connected to external electronic components to supply power.

[0006] Currently, it is difficult to determine the mounting positions of the polar poles and top cover, and the winding core and polar poles, making the assembly of battery cells highly complex. When the top cover is welded to the case, high precision is required in assembling the case and top cover, which increases costs. [Means for solving the problem]

[0007] The main object of this application is to provide an internal pole, a battery cell and a battery module, which aims to solve one or more of the following technical problems in the prior art, namely, a battery cell generally includes a case, a top cover and a core (or cell stack), the core being placed inside the case and having an upper end opening at the top of the case, the pole on the top cover of the battery being connected to the current collector of the core, the core being placed inside the case, the top cover of the battery being sealed by laser welding at the opening at the top of the case, and the pole formed on the top cover of the battery being able to electrically connect to external electronic components and supply power.

[0008] Currently, it is difficult to determine the mounting positions of the polar poles and top cover, and the winding core and polar poles, making the assembly of battery cells highly complex. When the top cover is welded to the case, high precision is required in assembling the case and top cover, which increases costs.

[0009] To achieve the object of the above invention, this application provides an inner pole post comprising a pole post body, at least one pole post connecting projection, and at least one pole post tab, wherein the pole post tab and the pole post connecting projection are fixed to both sides of the pole post body, respectively.

[0010] The pole tabs on the inner poles are used to connect to the cell stack and conduct electricity. The placement of the pole tabs allows for the identification of the connection point between the cell stack and the inner poles, ensuring secure mounting. The pole connection projections protrude from the battery cell case and connect to external electronic components to supply power. Furthermore, the pole connection projections allow for precise positioning relative to the case, reducing the difficulty of positioning and improving assembly efficiency.

[0011] Based on the above technical solutions, the present invention can be further improved as follows.

[0012] Furthermore, the pole column connecting projection has an injection hole that penetrates the pole column body and the pole column connecting projection.

[0013] The electrolyte can be injected into the battery cell case via the injection port. Since the injection port is integrated into the electrode post connecting protrusion, there is no need to provide a separate injection port in the case, which ensures the structural strength of the case and simplifies its structure.

[0014] Furthermore, an inner pole column has a conductive sheet welded to each pole column tab, and a plating layer on the outside of each pole column tab and the corresponding conductive sheet.

[0015] By welding a conductive sheet to the pole tab and then plating it, costs are reduced, and overcurrent protection between the cell stack and the pole tab can be achieved.

[0016] Furthermore, there are multiple pole column tabs, and the multiple pole column tabs are divided into at least one group of tabs arranged sequentially in the Y direction, and at least two of the pole column tabs in each group of tabs are spaced apart along the Z direction, and two adjacent pole column tabs are offset in the Y direction.

[0017] At least two pole column tabs are spaced apart along the Z direction, and in this way, when at least two cell stacks are sequentially connected to at least two pole column tabs, a stacked structure along the Z direction can be formed, facilitating the installation and positioning of the cell stacks. By staggering two adjacent pole column tabs in the Y direction, each cell stack is welded to the pole column tab with sufficient working space.

[0018] The present invention further provides a battery cell comprising a case, an outer pole, and an inner pole, wherein the inner pole is mounted inside the case, and the pole connecting projection penetrates the case and is fixedly connected to the outer pole located outside the case to conduct electricity.

[0019] The pole post connecting projections penetrate the case and conduct electricity to the outer pole posts, which then connect to external electronic components to supply power. The pole post connecting projections allow for precise positioning relative to the case, reducing the difficulty of positioning and improving assembly efficiency.

[0020] Furthermore, the battery cell further includes a rubber nail and a sealing top cover, wherein one of the pole-connecting projections in the inner pole has a liquid injection hole that penetrates the pole body and the pole-connecting projection, the rubber nail is attached to one end of the liquid injection hole facing the outside of the case, and the sealing top cover is fixedly connected to the pole-connecting projection and restricts the rubber nail.

[0021] The rubber nail seals the injection hole to prevent leakage, and the sealing top cover restricts the rubber nail.

[0022] Furthermore, the battery cell further includes a cell stack assembly, the cell stack assembly is mounted within the case, the cell stack assembly includes at least one cell stack, the inner terminal is located at an end of the case, and a current collector of the cell stack is connected in a one-to-one correspondence with a terminal tab of the inner terminal.

[0023] The inner terminal is located at an end of the case, the cell stack is horizontally disposed within the case, and the mounting position is determined by the terminal tab.

[0024] Furthermore, the battery cell further includes a pressure plate, the case includes a base case and an upper cover, the upper cover has a pressure relief groove, an upper wall of the base case is open, the upper cover closes the opening and is fixedly connected to the base case, the pressure plate is located between the upper cover and a connection portion of a current collector corresponding to the uppermost terminal tab, the pressure plate has an avoidance groove, and the pressure relief groove is correspondingly located within the avoidance groove. When the cell stack expands, the pressure relief groove on the upper surface of the case functions as an expansion space for the battery cell to prevent excessive air pressure within the case. The pressure plate can support the upper cover, thereby preventing the area of the case corresponding to the inner terminal on the upper cover from being deformed when the battery cell is manufactured (formation process) and the inside of the case is in a negative pressure state. The pressure plate is used to limit the position of the inner terminal. The inner terminal is provided at an end of the base case rather than on the upper cover, the upper wall of the base case is open, the cell stack assembly is mounted into the base case from the opening, and the mounting operation is convenient.

[0025] Furthermore, the terminal tab is plate-shaped, the base case is in the shape of a rectangular parallelepiped whose upper wall is the largest surface in terms of area, and the terminal tab is parallel to the upper cover.

[0026] The cell stack assembly is mounted into the base case from above, and the operation is simple and has a low difficulty level.

[0027] Furthermore, there are two inner terminal posts, namely a positive inner terminal post and a negative inner terminal post respectively, and there are two outer terminal posts, namely a positive outer terminal post and a negative outer terminal post respectively. The terminal post connection protrusion of the positive inner terminal post penetrates through the case and is connected to the positive outer terminal post to conduct electricity, and the terminal post connection protrusion of the negative inner terminal post penetrates through the case and is connected to the negative outer terminal post to conduct electricity.

[0028] Furthermore, the battery cell further includes an inner insulating member, a positive terminal post conductive plastic member, and a negative outer insulating member. The number of the inner insulating members is two, and the two inner insulating members are respectively fixed between the positive inner terminal post and the inner wall of the case and between the negative inner terminal post and the inner wall of the case. The positive terminal post conductive plastic member is fixed between the positive outer terminal post and the outer wall of the case, and the negative outer insulating member is fixed between the negative outer terminal post and the outer wall of the case.

[0029] The inner insulating member partitions the inner terminal post and the case. The inner terminal post and the outer terminal post are only connected by the terminal post connection protrusion to avoid electrical leakage from the case. The positive outer plastic member is a weakly conductive plastic. The positive outer terminal post is conductive with the case, and the case has a weak positive charge, thus enhancing the corrosion resistance of the case and extending its service life. The negative outer insulating member insulates the negative outer terminal post from the case and prevents the negative outer terminal post from being conductive with the case.

[0030] Furthermore, the case is provided with a rupture mark.

[0031] When the pressure inside the case is too high, the case breaks from the position of the rupture mark to release the pressure, thereby eliminating the need for welding a rupture disk to the case and achieving low cost.

[0032] The present invention further provides a battery module including the battery cell.

Effects of the Invention

[0033] The pole tabs of the inner poles according to the present invention are used to conduct electricity by connecting to the cell stack. By installing the pole tabs, the connection position between the cell stack and the inner poles can be identified, enabling reliable mounting. The pole connection projections protrude from the battery cell case and are used to supply power to external electronic components. Furthermore, the relative position of the pole connection projections can be accurately identified with respect to the case, reducing the difficulty of positioning and improving assembly efficiency. The electrolyte can be injected into the battery cell case through the electrolyte injection hole. Since the electrolyte injection hole is integrated into the pole connection projection, there is no need to provide a separate electrolyte injection hole in the case, ensuring the structural strength of the case and simplifying the case structure. By welding a conductive sheet to the pole tabs and plating them, costs are reduced and overcurrent between the cell stack and the pole tabs can be protected. At least two pole tabs are installed spaced apart along the Z direction. In this way, when at least two cell stacks are sequentially connected to at least two pole tabs, a stacked structure along the Z direction can be formed, making it easier to install and position the cell stacks. The two adjacent pole column tabs are positioned offset in the Y direction, ensuring that each cell stack is welded to the pole column tab with sufficient working space. The pole column connecting protrusions allow for precise positioning relative to the case, reducing the difficulty of positioning and improving assembly efficiency. Rubber nails seal the injection holes to prevent leakage, and the sealing top cover restricts the rubber nails.

[0034] The inner poles are located at the ends of the case, and the cell stack is positioned laterally within the case, with the mounting position determined by pole tabs. When the cell stack expands, the pressure relief grooves on the top surface of the case function as expansion spaces for the battery cells, preventing excessive air pressure within the case. The pressure plate supports the top cover, preventing negative pressure from forming inside the case during the manufacturing (chemical process) of the battery cells, and thus preventing deformation of the area corresponding to the top cover of the inner poles. The pressure plate is used to restrict the position of the inner poles. The inner poles are located at the ends of the base case rather than on the top cover, and the top wall of the base case is open, allowing the cell stack assembly to be installed inside the base case through the opening, making installation convenient. The cell stack assembly is installed inside the base case from the top, making the operation simple and easy. The inner insulating material separates the inner poles from the case, and the inner and outer poles are conductive only through the pole connection protrusions, preventing electrical leakage from the case. The positive electrode outer plastic component is made of a weakly conductive plastic, and the positive electrode outer pole is electrically connected to the case, causing the case to carry a weak positive charge. This enhances the corrosion resistance of the case and extends its service life. The negative electrode outer insulating component insulates the negative electrode outer pole from the case, preventing electrical contact between the negative electrode outer pole and the case. If the pressure inside the case becomes too high, the case will rupture at the location of the rupture mark to release the pressure, thus eliminating the need to weld a rupture disc to the case and resulting in a lower cost. [Brief explanation of the drawing]

[0035] [Figure 1] This is a perspective view of the inner pole column according to the present invention. [Figure 2] This is an exploded perspective view of the battery cell according to the present invention. [Figure 3] Figure 2 is a magnified view of a portion of the battery cell. [Figure 4] This is a front view of the battery cell according to the present invention. [Figure 5] This is a plan view of a battery cell according to the present invention. [Figure 6] Figure 5 is a left side view of the battery cell. [Figure 7]Figure 5 is a partially enlarged view of the cross-section of the battery cell along the D direction. The components represented by each symbol in the drawing are shown below. 100, Inner pole column; 101, Policing column body; 102, Policing column connecting projection; 103, Policing column tab; 104, Injection hole; 105, Positive inner pole column; 106, Negative inner pole column; 107, Conductive sheet; 200, Cell stack; 300, Case; 301, Base case; 302, Top cover; 303, Pressure relief groove; 400, Outer pole column; 401, Positive outer pole column; 402, Negative outer pole column; 500, Inner insulating member; 501, Positive inner insulating member; 502, Negative inner insulating member; 503, Restricting projection; 601, Positive pole column conductive plastic member; 602, Negative outer insulating member; 603, Rib; 700, Rubber nail; 800, Sealing top cover; 900, Pressure plate; 901, Separator; 1000, Mylar film. [Modes for carrying out the invention]

[0036] The principles and features of the present invention are described below, but the examples given are merely for interpretation purposes and do not limit the scope of the present invention. Example 1

[0037] As shown in Figure 1, this embodiment provides an inner pole post, the inner pole post 100 comprising a pole post body 101, at least one pole post connecting projection 102, and at least one pole post tab 103, the pole post tab 103 and the pole post connecting projection 102 being fixed to both sides of the pole post body 101, respectively.

[0038] The pole tabs 103 of the inner pole post 100 are used to conduct electricity by connecting to the cell stack 200. The placement of the pole tabs 103 allows for the identification of the connection position between the cell stack 200 and the inner pole post 100, ensuring secure mounting. The pole connection projections 102 protrude from the battery cell case 300 and are used to supply power by connecting to external electronic components. Furthermore, the pole connection projections 102 allow for precise identification of their relative position to the case 300, reducing the difficulty of positioning and improving assembly efficiency.

[0039] Specifically, the pole column tab 103 extends outward from the pole column body 101 in the X direction and has a tab surface for conducting electricity by being connected to the current collector of the cell stack 200.

[0040] Here, the number of pole column connecting protrusions 102 can be one or more. In one specific example, as shown in Figures 2 and 3, the number of pole column connecting protrusions 102 is two. Of course, in other examples, the number of pole column connecting protrusions 102 may be three or four or more.

[0041] Here, there may be one or more pole column tabs 103. If there are multiple pole column tabs 103, the following arrangement may be made: the multiple pole column tabs 103 may be divided into at least one group of tabs arranged sequentially in the Y direction, at least two of the pole column tabs 103 in each group of tabs may be spaced apart along the Z direction, and two adjacent pole column tabs 103 may be offset in the Y direction. At least two pole column tabs 103 may be spaced apart along the Z direction, and in this way, when at least two cell stacks 200 are sequentially connected to at least two pole column tabs 103, a stacked structure along the Z direction can be formed, making it easier to install and position the cell stacks 200. By offsetting two adjacent pole column tabs 103 in the Y direction, each cell stack 200 is welded to the pole column tabs 103 with sufficient working space.

[0042] Optionally, the inner pole post 100 may be integrally molded, or the pole post tab 103 and pole post connecting projection 102 may be manufactured separately and then fixed to the pole post body 101.

[0043] The material of the inner pole column 100 can be optionally carbon steel or another metal; if carbon steel is chosen, the material cost will be lower.

[0044] The pole column body 101 may optionally be plate-shaped or block-shaped. Example 2

[0045] As shown in Figure 1, this embodiment provides an inner pole post, the inner pole post 100 comprising a pole post body 101, at least one pole post connecting projection 102, and at least one pole post tab 103, the pole post tab 103 and the pole post connecting projection 102 being fixed to both sides of the pole post body 101, respectively.

[0046] The pole tabs 103 of the inner pole post 100 are used to conduct electricity by connecting to the cell stack 200. The placement of the pole tabs 103 allows for the identification of the connection position between the cell stack 200 and the inner pole post 100, ensuring secure mounting. The pole connection projections 102 protrude from the battery cell case 300 and are used to supply power by connecting to external electronic components. Furthermore, the pole connection projections 102 allow for precise identification of their relative position to the case 300, reducing the difficulty of positioning and improving assembly efficiency.

[0047] Specifically, the pole column tab 103 extends outward from the pole column body 101 in the X direction and has a tab surface for conducting electricity by being connected to the current collector of the cell stack 200.

[0048] Here, the number of pole column connecting protrusions 102 can be one or more. In one specific example, as shown in Figures 2 and 3, the number of pole column connecting protrusions 102 is two. Of course, in other examples, the number of pole column connecting protrusions 102 may be three or four or more.

[0049] Here, there may be one or more pole column tabs 103. If there are multiple pole column tabs 103, the multiple pole column tabs 103 are divided into at least one group of tabs arranged sequentially in the Y direction, and at least two of the pole column tabs 103 in each group of tabs are spaced apart along the Z direction, and two adjacent pole column tabs 103 are offset in the Y direction. At least two pole column tabs 103 are spaced apart along the Z direction, and in this way, when at least two cell stacks 200 are sequentially connected to at least two pole column tabs 103, a stacked structure along the Z direction can be formed, making it easier to install and position the cell stacks 200. By offsetting two adjacent pole column tabs 103 in the Y direction, each cell stack 200 is welded to the pole column tabs 103 with sufficient working space.

[0050] Optionally, the inner pole post 100 may be integrally molded, or the pole post tab 103 and pole post connecting projection 102 may be manufactured separately and then fixed to the pole post body 101. Optionally, the material of the inner pole post 100 may be carbon steel or another metal; if carbon steel is selected, the material cost will be lower.

[0051] The pole column body 101 may optionally be plate-shaped or block-shaped.

[0052] Furthermore, the pole column connecting projection 102 has an injection hole 104 that penetrates the pole column body 101 and the pole column connecting projection 102.

[0053] The electrolyte can be injected into the battery cell case 300 via the electrolyte injection port 104. Since the electrolyte injection port 104 is integrated into the electrode column connecting projection 102, there is no need to provide a separate electrolyte injection port 104 in the case 300, which ensures the structural strength of the case 300 and simplifies its structure.

[0054] In this case, if there are multiple pole column connecting protrusions 102, at least one pole column connecting protrusion 102 is provided with an injection hole 104. In one specific example, there are multiple pole column connecting protrusions 102, but only one pole column connecting protrusion 102 has an injection hole 104. Example 3

[0055] Based on Example 1 or Example 2, a conductive sheet 107 is welded to each pole tab 103, and a plating layer is provided on the outside of each pole tab 103 and the corresponding conductive sheet 107.

[0056] By welding the conductive sheet 107 to the pole tab 103 and then plating it, costs are reduced, and overcurrent protection between the cell stack 200 and the pole tab 103 is achieved.

[0057] Specifically, first the conductive sheet 107 is welded to the pole tab 103, and after the welding is complete, the entire outside of the pole tab 103 and conductive sheet 107 is plated.

[0058] In one specific example, when the pole column tab 103 is positioned horizontally, a conductive sheet 107 is welded to its upper or lower surface.

[0059] Furthermore, the outside of the pole column body 101 may be plated.

[0060] Optionally, the conductive sheet 107 may be a copper plate or another sheet-like material having excellent conductivity.

[0061] Optionally, the plating layer may be a nickel plating layer, a silver plating layer, or a copper plating layer having excellent conductivity.

[0062] In one specific example, the inner pole column 100 functions as the positive inner pole column 105, and the positive inner pole column 105 is integrally molded, with aluminum selected as its material.

[0063] In another specific example, the inner pole 100 functions as the negative inner pole 106, which is integrally molded, with carbon steel or another metal selected as its material. A copper plate is welded to the pole tab 103, and then nickel plating is applied to the outside of the pole tab 103 and the entire copper plate. Compared to conventional technology using copper for the entire negative inner pole, the inner pole in this example reduces costs and also guarantees overcurrent protection. Example 4

[0064] Based on any one of Examples 1 to 4, as shown in Figures 2 to 7, this embodiment provides a battery cell comprising a case 300, an outer pole 400, and the inner pole 100, wherein the inner pole 100 is mounted inside the case 300, and the pole connecting projection 102 penetrates the case 300 and is fixedly connected to the outer pole 400 located outside the case 300 to conduct electricity.

[0065] The pole post connecting projection 102 penetrates the case 300 and conducts electricity to the outer pole post 400, which is then connected to an external electronic component to receive power. The pole post connecting projection 102 can accurately determine its relative position to the case 300, reducing the difficulty of positioning and improving assembly efficiency.

[0066] Here, the case 300 is provided with pole pole through-holes, and the pole pole connecting projection 102 passes through the pole pole through-holes and through the case 300 to connect to the outer pole pole 400.

[0067] Here, the pole column connecting projection 102 and the outer pole column 400 may be connected by welding, riveting, or other fixing connection methods.

[0068] In one specific example, as shown in Figure 7, the pole column connecting projection 102 is connected to the outer pole column 400 by rivet crimping. Specifically, one end of the pole column connecting projection 102 passes through the through hole in the outer pole column 400 and is then crimped to form an end with a diameter larger than the diameter of the through hole in the outer pole column 400, thereby achieving positional restriction. Example 5

[0069] Based on any one of Examples 1 to 4, as shown in Figures 2 to 7, this embodiment provides a battery cell comprising a case 300, an outer pole 400, and the inner pole 100, wherein the inner pole 100 is mounted inside the case 300, and the pole connecting projection 102 penetrates the case 300 and is fixedly connected to the outer pole 400 located outside the case 300 to conduct electricity.

[0070] The pole post connecting projection 102 penetrates the case 300 and conducts electricity to the outer pole post 400, which is then connected to an external electronic component to receive power. The pole post connecting projection 102 can accurately determine its relative position to the case 300, reducing the difficulty of positioning and improving assembly efficiency.

[0071] Here, the case 300 is provided with pole pole through-holes, and the pole pole connecting projection 102 passes through the pole pole through-holes and through the case 300 to connect to the outer pole pole 400.

[0072] Here, the pole post connecting projection 102 and the outer pole post 400 may be connected by welding, riveting, or other fixing connection methods. In one specific example, as shown in Figure 7, the pole post connecting projection 102 is connected to the outer pole post 400 by riveting, specifically, one end of the pole post connecting projection 102 passes through the through hole of the outer pole post 400 and is then crimped to form an end with a diameter larger than the diameter of the through hole of the outer pole post 400, thereby achieving positional constraint.

[0073] Furthermore, the battery cell further includes a rubber nail 700 and a sealing top cover 800, wherein one of the pole column connecting projections 102 on the inner pole column 100 has an injection hole 104 that penetrates the pole column body 101 and the pole column connecting projection 102, the rubber nail 700 is attached to one end of the injection hole 104 facing the outside of the case, and the sealing top cover 800 is fixedly connected to the pole column connecting projection 102 and restricts the rubber nail 700.

[0074] The rubber nail 700 seals the liquid injection hole 104 to prevent leakage, and the sealing top cover 800 restricts the rubber nail 700. Example 6

[0075] Based on Example 4 or Example 5, the battery cell further includes a cell stack assembly, the cell stack assembly is mounted within the case 300, the cell stack assembly includes at least one cell stack 200, the inner pole 100 is located at the end of the case 300, and the current collector of the cell stack 200 is connected in a one-to-one correspondence with the pole tab 103 of the inner pole 100.

[0076] The inner pole post 100 is located at the end of the case 300, and the cell stack 200 is positioned laterally within the case 300, with its mounting position determined by the pole post tab 103. The inner pole column 100 is located at the end of the case 300, specifically at the end of the case 300 in the X direction.

[0077] Specifically, each end of the cell stack 200 has a positive electrode current collector and a negative electrode current collector, all of the positive electrode current collectors of the cell stack 200 are directed toward the same end of the cell stack assembly, there are two inner pole posts 100, called the positive inner pole post 105 and the negative inner pole post 106, the two inner pole posts 100 are provided at each end of the case 300, all pole post tabs 103 of the positive inner pole post 105 are connected in a one-to-one correspondence with all of the positive electrode current collectors, and all pole post tabs 103 of the negative inner pole post 106 are provided and connected in a one-to-one correspondence with all of the negative electrode current collectors.

[0078] Correspondingly, there are also two outer pole posts 400, which are called the positive outer pole post 401 and the negative outer pole post 402, respectively. The positive outer pole post 401 and the negative outer pole post 402 are provided on the outside of both ends of the case 300, and the pole post connecting projection 102 of the positive inner pole post 105 penetrates the case 300 and connects to the positive outer pole post 401 to conduct electricity, and the pole post connecting projection 102 of the negative inner pole post 106 penetrates the case 300 and connects to the negative outer pole post 402 to conduct electricity.

[0079] In one specific example, the positive electrode inner pole 105 is integrally molded and made of aluminum. The negative electrode inner pole 106 is integrally molded and made of carbon steel or another metal, with a copper plate welded to the pole tab 103, and then nickel-plated on the outside of the pole tab 103 and the copper plate as a whole. Compared to conventional technology in which copper is used for the entire negative electrode inner pole, the inner poles in this example offer reduced costs and guaranteed overcurrent protection.

[0080] In one specific example, the fluid injection hole 104 is provided only on one pole-connecting projection 102 of the positive electrode inner pole 105 or the negative electrode inner pole 106. For example, as shown in Figures 2-7, the fluid injection hole 104 is provided only on one pole-connecting projection 102 of the positive electrode inner pole 105.

[0081] Furthermore, the outside of the cell stack assembly is further wrapped with Mylar film 1000. The Mylar film 1000 serves an insulating and protective purpose. Specifically, the Mylar film 1000 wraps around the outside of the main bodies of the multiple cell stacks 200, and the current collectors of the cell stacks 200 are exposed from the Mylar film 1000 so that they can be easily connected to the pole tabs 103.

[0082] Specifically, if there are multiple pole column tabs 103, the multiple pole column tabs 103 are divided into at least two tab groups arranged sequentially in the Y direction, and at least two of the pole column tabs 103 in each tab group are spaced apart along the Z direction, with two adjacent pole column tabs 103 being offset in the Y direction. Correspondingly, the cell stack assembly includes multiple cell stacks 200, which are divided into at least two cell stack groups arranged sequentially in the Y direction, and the two cell stack groups are provided in a one-to-one correspondence with two tab groups, and at least two cell stacks 200 in each cell stack group are stacked sequentially in the Z direction and connected in a one-to-one correspondence with at least two pole column tabs 103 of the corresponding tab group. Example 7

[0083] Based on Embodiment 6, the battery cell further includes a pressure plate 900, the case 300 includes a base case 301 and an upper cover 302, the upper cover 302 having a pressure relief groove 303, the upper wall of the base case 301 being open, the upper cover 302 being fixedly connected to the base case 301 by closing the opening, the pressure plate 900 being located between the upper cover 302 and the connection portion of the current collector corresponding to the uppermost pole column tab 103, the pressure plate 900 having a relief groove, the pressure relief groove 303 correspondingly located within the relief groove.

[0084] When the cell stack 200 expands, the pressure relief grooves 303 on the top surface of the case 300 function as expansion spaces for the battery cells, preventing excessive air pressure inside the case 300. The pressure plate 900 is used to restrict the position of the inner pole posts 100. As shown in Figure 7, the main body of the cell stack 200 contacts the top cover 302, and the inside of the top cover 302 is suspended by the inner pole posts 100. The pressure plate 900 can also support the top cover 302 by the inner pole posts 100, thereby preventing negative pressure from forming inside the case 300 during the manufacturing (chemical process) of the battery cells and preventing deformation of the area of ​​the inner pole posts 100 corresponding to the top cover 302, thereby increasing structural reliability. The inner pole posts 100 are located at the end of the base case 301 rather than on the top cover 302, and the top wall of the base case 301 is open, allowing the cell stack assembly to be installed inside the base case 301 through the opening, making installation convenient.

[0085] Optionally, the base case 301 and the upper cover 302 are welded together, and more preferably, as shown in Figures 2-7, the upper edge of the base case 301 and the edge of the upper cover 302 are fixed by a flange process, which facilitates the stacking of multiple battery cells as a group. Furthermore, the case 300 is easy to assemble, the cost of the flange equipment is lower than that of welding equipment, and subsequent repairs and maintenance of the equipment and fixtures are simple.

[0086] Furthermore, the pole column tab 103 is plate-shaped, the base case 301 is a rectangular parallelepiped with its top wall being the largest surface area, and the pole column tab 103 is parallel to the top cover 302. Since the top surface of the base case 301 is the largest surface area in this rectangular parallelepiped structure, it is convenient to install the cell stack assembly into the base case 301 from the top surface.

[0087] Here, as shown in Figure 3, when the multiple cell stacks 200 are divided into at least two cell stack groups arranged sequentially along the Y direction, the lower end of the pressure plate 900 further has at least one separator 901 extending downward, and the separator 901 is located between two adjacent cell stack groups. By separating the adjacent cell stack groups, the separator 901 can avoid current interference between adjacent cell stack groups and prevent lateral vibration of the cell stack assembly. Example 8

[0088] Based on Example 7, the battery cell further includes an inner insulating member 500, a positive electrode column conductive plastic member 601, and a negative electrode outer insulating member 602, wherein the number of inner insulating members 500 is two. The two inner insulating members 500 are fixed between the positive inner pole 105 and the inner wall of the case 300, and between the negative inner pole 106 and the inner wall of the case 300, The positive electrode pole conductive plastic member 601 is fixed between the positive electrode outer pole 401 and the outer wall of the case 300, and the negative electrode outer insulating member 602 is fixed between the negative electrode outer pole 402 and the outer wall of the case 300.

[0089] The inner insulating member 500 separates the inner pole 100 from the case 300, and the inner pole 100 and the outer pole 400 are electrically connected only by the pole connection projection 102, thus preventing electrical leakage from the case 300. The positive electrode outer plastic member is made of a weakly conductive plastic, and the positive electrode outer pole 401 is electrically connected to the case 300, causing the case 300 to carry a weak positive charge, thereby increasing the corrosion resistance of the case 300 and extending its service life. The negative electrode outer insulating member 602 insulates the negative electrode outer pole 402 from the case 300, preventing electrical connection between the negative electrode outer pole 402 and the case 300.

[0090] Specifically, there are two inner insulating members 500, a positive electrode inner insulating member 501 and a negative electrode inner insulating member 502. The positive electrode inner insulating member 501 is fixed between the positive electrode inner pole 105 and the inner wall of the case 300, and the negative electrode inner insulating member 502 is fixed between the negative electrode inner pole 106 and the inner wall of the case 300.

[0091] Furthermore, as shown in Figure 3, there are restricting protrusions 503 at both ends of the inner insulating member 500 in the Y direction, and the inner pole column 100 is restricted between the two restricting protrusions 503 of the corresponding inner insulating member 500, thereby specifying its mounting position.

[0092] Furthermore, as shown in Figure 3, annular ribs 603 are formed on the edges of both the positive electrode pole conductive plastic member 601 and the negative electrode outer insulating member 602. The positive electrode outer pole 401 and the negative electrode outer pole 402 are fixed within the corresponding ribs 603, respectively, and are restricted by the ribs 603, thereby specifying their mounting positions. Example 9

[0093] Based on Examples 4 to 8, the case 300 is provided with rupture marks.

[0094] If the pressure inside case 300 becomes too high, case 300 will rupture at the location of the rupture mark to release the pressure, thus eliminating the need to weld a rupture disc to case 300 and resulting in a lower cost. Example 10

[0095] Based on Examples 4 to 9, this embodiment further provides a battery module including the battery cell.

[0096] In describing the present invention, the directions or positional relationships indicated by terms such as "X," "Y," "Z," "up," "down," "inside," and "outside" are those shown in the accompanying drawings, and their purpose is solely to facilitate the description of the present invention and simplify the description. They do not explicitly or implicitly suggest that the mentioned devices or elements necessarily have a specific direction, are composed of, or are operated in a specific direction, and should not be understood as limitations of the present invention.

[0097] In the description of this invention, "multiple" means at least two, for example, two, three, etc., unless otherwise specified.

[0098] In the present invention, unless otherwise explicitly defined or limited, the presence of a first feature "above" or "below" a second feature may be direct contact between the first and second features, or indirect contact through an intermediate medium between them. Furthermore, the presence of a first feature "above," "above," and "on the top surface" of a second feature may mean that the first feature is directly above or diagonally above the second feature, or simply that the horizontal height of the first feature is greater than that of the second feature. The presence of a first feature "below," "below," and "on the bottom surface" of a second feature may mean that the first feature is directly below or diagonally below the second feature, or simply that the horizontal height of the first feature is lower than that of the second feature.

[0099] In this specification, any reference to terms such as “one embodiment,” “several embodiments,” “example,” “specific example,” or “several examples” means that the specific features, structures, materials, or properties described based on the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, exemplary expressions for the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or properties described can be combined in appropriate ways in any one or more embodiments or examples. Moreover, those skilled in the art can combine different embodiments or examples and features of different embodiments or examples described herein without contradiction.

[0100] In describing this invention, unless explicitly defined or limited, the terms “attach,” “connect,” and “connect” should be understood broadly, for example, and may be fixed connections, removable connections or integral connections; mechanical connections or electrical connections; direct connections or indirect connections via an intermediate medium; or communication between two elements. Those skilled in the art will understand the specific meaning of these terms in this invention depending on the specific context.

[0101] The foregoing are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are also included within the scope of protection of the present invention. [Explanation of symbols]

[0102] 100, medial pole; 101 Main body of pole; 102 Polar column connecting projection; 103 Polar column tab; 104 Liquid injection hole; 105 Positive inner pole; 106 Negative inner pole; 107 Conductive sheet; 200 Cell stack; 300 Case; 301 Bass case; 302 Top cover; 303 Pressure relief groove; 400 Outer pole; 401 Positive outer pole; 402 Negative outer pole; 500 Inner insulating material; 501 Positive electrode inner insulating material; 502 Negative electrode inner insulating material; 503 Restrictive projection; 601 Positive pole column conductive plastic member; 602 Negative electrode outer insulating member; 603 Rib; 700 Rubber nails; 800 Sealing top cover; 900 Pressure plate; 901 Separator; 1000 Mylar film

Claims

1. It includes a pole column body, at least one pole column connecting projection, and at least one pole column tab, wherein the pole column tab and the pole column connecting projection are fixed to both sides of the pole column body, The pole column connecting projection has an injection hole that penetrates the pole column body and the pole column connecting projection. An inner pole column, wherein a conductive sheet is welded to each pole column tab, and a plating layer is provided on the outside of each pole column tab and the corresponding conductive sheet.

2. The inner pole column according to claim 1, wherein there are a plurality of pole column tabs, the plurality of pole column tabs are divided into at least one group of tabs sequentially provided in the Y direction, at least two of the pole column tabs of each group of tabs are spaced apart along the Z direction, and two adjacent pole column tabs are offset in the Y direction.

3. Including the case, outer poles, and inner poles, The inner pole post includes a pole post body, at least one pole post connecting projection, and at least one pole post tab, the pole post tab and the pole post connecting projection being fixed to both sides of the pole post body, The inner pole is mounted inside the case, and the pole connecting projection penetrates the case and is fixedly connected to the outer pole located outside the case to conduct electricity. The pole column connecting projection has an injection hole that penetrates the pole column body and the pole column connecting projection. A battery cell having a conductive sheet welded to each of the pole tabs, and a plating layer on the outside of each of the pole tabs and the corresponding conductive sheet.

4. The battery cell according to claim 3, wherein there are a plurality of pole column tabs, the plurality of pole column tabs are divided into at least one group of tabs arranged sequentially in the Y direction, at least two of the pole column tabs of each group of tabs are spaced apart along the Z direction, and two adjacent pole column tabs are offset in the Y direction.

5. The battery cell according to claim 3, further comprising a rubber nail and a sealing top cover, wherein one of the pole-connecting projections in the inner pole has a liquid injection hole that penetrates the pole body and the pole-connecting projection, the rubber nail is attached to one end of the liquid injection hole facing the outside of the case, and the sealing top cover is fixedly connected to the pole-connecting projection to restrict the rubber nail.

6. The battery cell according to claim 3, further comprising a cell stack assembly, the cell stack assembly mounted within the case, the cell stack assembly comprising at least one cell stack, the inner poles located at the ends of the case, and the current collectors of the cell stack connected in one-to-one correspondence with the pole tabs of the inner poles.

7. The battery cell according to claim 6, further comprising a pressure plate, the case comprising a base case and an upper cover, the upper cover having a pressure relief groove, the upper wall of the base case being open, the upper cover being fixedly connected to the base case by closing the opening in the upper wall of the base case, the pressure plate being located between the upper cover and the connection portion of the current collector corresponding to the uppermost pole column tab, the pressure plate having a relief groove, the pressure relief groove correspondingly located within the relief groove.

8. The battery cell according to claim 7, wherein the pole tab is plate-shaped, the base case is a rectangular parallelepiped with the upper wall being the largest surface area, and the pole tab is parallel to the upper cover.

9. The battery cell according to claim 3, wherein there are two inner electrode posts, one being a positive electrode inner electrode post and the other a negative electrode inner electrode post, and there are two outer electrode posts, one being a positive electrode outer electrode post and the other a negative electrode outer electrode post, the electrode post connecting projection of the positive electrode inner electrode post penetrates the case and connects to the positive electrode outer electrode post to conduct electricity, and the electrode post connecting projection of the negative electrode inner electrode post penetrates the case and connects to the negative electrode outer electrode post to conduct electricity.

10. The battery cell further includes an inner insulating member, a positive electrode column conductive plastic member, and a negative electrode outer insulating member, wherein there are two of the inner insulating members. The two inner insulating members are fixed between the positive inner pole and the inner wall of the case, and between the negative inner pole and the inner wall of the case, The battery cell according to claim 9, wherein the positive electrode pole conductive plastic member is fixed between the positive electrode outer pole and the outer wall of the case, and the negative electrode outer insulating member is fixed between the negative electrode outer pole and the outer wall of the case.

11. The battery cell according to claim 3, wherein the case is provided with a rupture mark.

12. The battery cell according to claim 4, wherein the case is provided with a rupture mark.

13. The battery cell according to claim 5, wherein the case is provided with a rupture mark.

14. The battery cell according to claim 6, wherein the case is provided with a rupture mark.

15. The battery cell according to claim 7, wherein the case is provided with a rupture mark.

16. The battery cell according to claim 8, wherein the case is provided with a rupture mark.

17. The battery cell according to claim 9, wherein the case is provided with a rupture mark.

18. A battery module comprising the battery cell described in claim 3.

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