Cylindrical battery negative electrode current collecting structure and manufacturing method thereof

Abstract

The application provides a cylindrical battery negative electrode current collecting structure and a manufacturing method thereof. The cylindrical battery negative electrode current collecting structure comprises a negative electrode current collecting disc, a core negative electrode current collector, and a negative electrode plate. The negative electrode current collecting disc comprises a disc body and a disc flange. The core negative electrode current collector is formed by a blank base material on one side of the negative electrode plate and comprises a bottom wall and a side wall. Before the negative electrode plate is wound, a front section of the blank base material is cut to form a plurality of blank base material pieces. After the negative electrode plate is wound, the blank base material pieces are bent towards the center of the core and overlap with each other, so that the bottom wall is formed at the center of the core negative electrode. A middle and rear section of the blank base material is kept in a vertical state and is wound into multiple turns to form the side wall. The negative electrode current collecting disc is installed in a space surrounded by the bottom wall and the side wall. The disc body is in contact with the bottom wall, and the disc flange is welded to the side wall.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of batteries, and particularly relates to a cylindrical battery negative electrode current collection structure and a manufacturing method thereof. BACKGROUND

[0002] Cylindrical lithium ion batteries are widely used as a kind of chemical power source that can be repeatedly charged and discharged. In the existing cylindrical lithium ion batteries, the negative electrode current collection disc is usually directly welded on the negative electrode end face of the winding core. Since the welding point is very close to the separator in the winding core, the welding heat is easy to burn the separator in the winding core when the negative electrode current collection disc is welded with the negative electrode end face of the winding core, which causes the risk of short circuit of the winding core, thereby causing the problem of low qualified rate of finished products. SUMMARY

[0003] The application is carried out to solve the above technical problems, and aims to provide a cylindrical battery negative electrode current collection structure and a manufacturing method thereof, which can effectively reduce the risk of short circuit of the winding core, thereby improving the qualified rate of finished products.

[0004] To achieve the above-mentioned purpose, the application adopts the following technical scheme:

[0005] <Scheme I>

[0006] The application provides a cylindrical battery negative electrode current collection structure, which has the following characteristics: a negative electrode current collection disc, comprising a current collection disc body and a current collection disc flange integrally formed on the outer edge of the current collection disc body and extending upward; and a winding core negative electrode current collector formed by a blanking base material on one side of a negative electrode plate, comprising a current collector bottom wall and a current collector side wall located on the outer edge of the current collector bottom wall, wherein, before the negative electrode plate is wound, the front section of the blanking base material is cut to form a plurality of blanking base material pieces; after the negative electrode plate is wound, the plurality of blanking base material pieces are respectively laid down in the center direction of the winding core and overlap with each other to form the current collector bottom wall at the central position of the negative electrode end of the winding core, and the middle and rear sections of the blanking base material are kept in a vertical state and wound into multiple turns to form the current collector side wall; the negative electrode current collection disc is installed in the space surrounded by the current collector bottom wall and the current collector side wall, the current collection disc body is in contact with the current collector bottom wall, and the current collection disc flange is welded with the current collector side wall.

[0007] In the cylindrical battery negative electrode current collection structure provided by the application, the current collection disc body can also have the following characteristics: the current collection disc body is provided with a plurality of holes, and a plurality of downward protruding burrs are arranged at the edge of each hole; and conductive glue is coated at the hole position of the negative electrode current collection disc body.

[0008] In the cylindrical battery negative electrode current collection structure provided by the application, the blanking base material can also have the following characteristics: the length of the front section of the blanking base material is 20-50% of the length of the entire blanking base material.

[0009] The cylindrical battery negative electrode current collector structure provided by the present invention may also have the following feature: the number of blank substrate sheets is not less than 5.

[0010] The cylindrical battery negative electrode current collector structure provided by the present invention may also have the following feature: the number of turns of the middle and rear section of the blank substrate is not less than 5 turns.

[0011] Option Two

[0012] This invention also provides a method for manufacturing a negative electrode current collector structure for a cylindrical battery, characterized by the following steps:

[0013] Step S1: Cut multiple notches at designated positions on the front section of the blank substrate on one side of the slit negative electrode plate to form multiple blank substrate sheets.

[0014] Step S2: The negative electrode plate, positive electrode plate, and separator are wound into a core. During winding, the blank substrate sheet is pre-pressed towards the center of the core. The middle and rear sections of the blank substrate are kept vertical and wound into multiple turns.

[0015] Step S3: Shape the pre-folded blank substrate sheet so that all blank substrate sheets are folded down and overlap each other to form a current collector bottom wall at the center of the negative end of the core; and roll-shape the middle and rear sections of the blank substrate sheet that has been wound into multiple turns to form a current collector side wall.

[0016] Step S4: Place the negative current collector into the space enclosed by the bottom wall and side wall of the current collector and press it tightly. Flip the negative current collector and weld it to the side wall of the current collector. Apply conductive adhesive to the holes of the negative current collector. This completes the fabrication of the negative current collector structure of the cylindrical battery.

[0017] The role and effect of invention

[0018] According to the cylindrical battery negative electrode current collector structure and manufacturing method of the present invention, since the current collector of the core is formed by the blank substrate on one side of the negative electrode plate, multiple blank substrate sheets in the front section of the blank substrate are respectively bent down towards the center of the core and overlap each other, thereby forming a current collector bottom wall at the center of the negative electrode of the core. The middle and rear sections of the blank substrate are kept vertical and wound into multiple turns to form a current collector side wall. The negative electrode current collector is installed in the space enclosed by the current collector bottom wall and the current collector side wall. The current collector disc body is in contact with the current collector bottom wall, and the current collector flange is welded to the current collector side wall, so that the welding point is far away from the separator in the core. This can effectively avoid the welding heat burning the separator during welding, reduce the risk of short circuit in the core, thereby improving the yield of finished products and effectively improving the high current conduction capacity of the battery. Moreover, the front section of the blank substrate is cut with multiple notches before the negative electrode plate is wound to form multiple blank substrate sheets, which is conducive to bending towards the center of the core, and no more dust will be generated during the bending process, reducing the risk of short circuit of the core. Attached Figure Description

[0019] Figure 1 This is a three-dimensional structural diagram of the cylindrical battery negative electrode current collector structure in an embodiment of the present invention;

[0020] Figure 2 This is a top-view three-dimensional structural diagram of the negative electrode current collector in an embodiment of the present invention;

[0021] Figure 3 This is a bottom-view three-dimensional structural diagram of the negative electrode current collector in an embodiment of the present invention;

[0022] Figure 4 This is a three-dimensional structural schematic diagram of the core current collector in an embodiment of the present invention; and

[0023] Figure 5 This is a schematic diagram of the negative electrode plate and the blank substrate in an embodiment of the present invention. Detailed Implementation

[0024] The following will further explain the concept, specific structure, and technical effects of the present invention in conjunction with the accompanying drawings, so as to fully understand the purpose, features, and effects of the present invention.

[0025] <Example>

[0026] Figure 1 This is a three-dimensional structural diagram of the negative electrode current collector structure of a cylindrical battery in an embodiment of the present invention.

[0027] like Figure 1 As shown, in this embodiment, the cylindrical battery negative electrode current collector 100 includes a negative electrode current collector disk 10 and a core current collector 20.

[0028] Figure 2This is a top-view three-dimensional structural diagram of the negative electrode current collector in an embodiment of the present invention; Figure 3 This is a bottom-view three-dimensional structural diagram of the negative current collector in an embodiment of the present invention.

[0029] like Figures 1 to 3 As shown, the negative electrode current collector 10 includes a current collector plate body 11 and a current collector plate flange 12.

[0030] The collector plate body 11 is circular, with an upwardly protruding negative electrode post 111 integrally formed at its center. In this embodiment, the collector plate body 11 is provided with a plurality of holes 112, and each hole 112 has a plurality of downwardly protruding burrs 112a at its edge.

[0031] The collector plate flange 12 is integrally formed on the outer edge of the collector plate body 11 and extends upward.

[0032] Figure 4 This is a three-dimensional structural schematic diagram of the core current collector in an embodiment of the present invention; Figure 5 This is a schematic diagram of the negative electrode plate and the blank substrate in an embodiment of the present invention.

[0033] like Figure 1 and Figure 4 As shown, the core current collector 20 is located at the negative end of the core 200 and has a shape that matches the negative current collector disk 10. The core current collector 20 includes a current collector bottom wall 21 and a current collector side wall 22. The current collector side wall 22 is cylindrical and located at the outer edge of the current collector bottom wall 21.

[0034] Core current collector 20 is made of Figure 5 The blank substrate 220 shown is formed on one side of the negative electrode plate 210 used to form the core 200. In this embodiment, the substrate of the negative electrode plate 210 is copper foil.

[0035] like Figure 5 As shown, before the negative electrode plate 210 is wound, the front section 221 of the blank substrate 220 is cut with multiple notches to form multiple blank substrate sheets 221a. In this embodiment, the length of the front section 221 is 20-50% of the length of the entire blank substrate 220; the number of blank substrate sheets 221a is not less than 5.

[0036] After the negative electrode plate 210, positive electrode plate, and separator are wound together, multiple blank substrate sheets 221a in the front section 221 of the blank substrate 220 are bent down and overlap each other towards the center of the core 200, thereby forming a current collector bottom wall 21 at the center of the negative end of the core 200; the middle and rear sections 222 of the blank substrate 220 are wound into multiple turns while remaining vertical, thereby forming a current collector side wall 22. In this embodiment, the middle and rear sections 222 are wound into at least 5 turns.

[0037] like Figure 4 As shown, the space enclosed by the bottom wall 21 and the side wall 22 of the current collector forms a receiving cavity for accommodating the negative electrode current collector 10. The negative electrode current collector 10 is installed in this receiving cavity, and the burrs 112a on the bottom surface of the current collector body 11 abut against the bottom wall 21 of the current collector; the flange 12 of the current collector is welded to the side wall 22 of the current collector to form a main current flow structure. In this embodiment, conductive adhesive is applied at the hole 112 position of the current collector body 11.

[0038] In this embodiment, a method for manufacturing the above-mentioned cylindrical battery negative electrode structure 100 is also provided. The method includes the following steps:

[0039] Step S1: Cut multiple notches at designated positions on the front section 221 of the blank substrate 220 on one side of the slit negative electrode plate 210 to form multiple blank substrate pieces 221a.

[0040] In step S2, the negative electrode plate 210, the positive electrode plate, and the separator are wound into a core. During winding, the blank substrate sheet 221a is pre-pressed towards the center of the core 200, and the middle and rear sections 222 of the blank substrate 220 are wound into multiple turns while maintaining a vertical state.

[0041] Step S3: Shape the pre-folded blank substrate sheet 221a so that all blank substrate sheets 221a are folded down and overlap each other to form a current collector bottom wall 21 at the center of the negative end of the core 200; and roll-shape the middle and rear section 222 of the blank substrate 220 that has been wound into multiple turns to form a current collector side wall 22.

[0042] Step S4: Place the negative current collector 10 into the space enclosed by the bottom wall 21 and the side wall 22 of the current collector and press it tightly. Weld the flange 12 of the negative current collector to the side wall 22 of the current collector. Apply conductive adhesive to the hole 112 of the current collector body 11 of the negative current collector 10. This completes the fabrication of the cylindrical battery negative current collector structure 100.

[0043] The role and effect of the embodiments

[0044] According to the cylindrical battery negative electrode current collector structure and its manufacturing method involved in this embodiment, the current collector is formed by the blank substrate on one side of the negative electrode plate. Multiple blank substrate sheets in the front section of the blank substrate are bent down and overlap each other towards the center of the core, thereby forming the bottom wall of the current collector at the center of the negative electrode of the core. The middle and rear sections of the blank substrate are kept vertical and wound into multiple turns to form the side wall of the current collector. The negative electrode current collector is installed in the space enclosed by the bottom wall and the side wall of the current collector. The current collector disc body is in contact with the bottom wall of the current collector, and the flange of the current collector is welded to the side wall of the current collector, so that the welding point is far away from the separator in the core. This can effectively avoid the welding heat burning the separator during welding, reduce the risk of short circuit in the core, thereby improving the yield rate of finished products and effectively improving the high current conduction capacity of the battery. Moreover, the front section of the blank substrate is cut with multiple notches before the negative electrode plate is wound to form multiple blank substrate sheets, which is conducive to bending towards the center of the core, and no more dust will be generated during the bending process, reducing the risk of short circuit of the core.

[0045] In addition, the current collector plate has multiple holes, and each hole has multiple downward protruding burrs at its edge. The burrs abut against the bottom wall of the current collector and may even penetrate into it, which increases the contact and flow conduction between the current collector plate and the bottom wall of the current collector and improves the battery's flow conduction capability.

[0046] In addition, applying conductive adhesive to the holes in the current collector plate further increases the contact and current conduction between the current collector plate and the bottom wall of the current collector, thereby further improving the current conduction capacity of the battery.

[0047] The above embodiments are preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention.

Claims

1. A current collector structure for the negative electrode of a cylindrical battery, characterized in that, include: The negative current collector includes a current collector body and a current collector flange integrally formed on the outer edge of the current collector body and extending upward; as well as The core negative electrode current collector is formed from the blank substrate on one side of the negative electrode plate, and includes a current collector bottom wall and a current collector side wall located at the outer edge of the current collector bottom wall. Before the negative electrode plate is wound, the front section of the blank substrate is cut with multiple notches to form multiple blank substrate sheets. After the negative electrode plate is wound, the multiple blank substrate sheets fall down towards the center of the core and overlap each other to form the current collector bottom wall at the center of the negative end of the core. The middle and rear sections of the blank substrate are kept vertical and wound into multiple turns to form the current collector side wall. The negative electrode current collector is installed within the space enclosed by the bottom wall and the side wall of the current collector. The current collector body is in contact with the bottom wall of the current collector, and the flange of the current collector is welded to the side wall of the current collector. The collector plate has multiple holes, and each hole has multiple downward-protruding burrs at its edge. These burrs abut against the bottom wall of the collector. Apply conductive adhesive to the holes in the collector plate body. The length of the front section of the blank substrate is 20-50% of the total length of the blank substrate.

2. The cylindrical battery negative electrode current collector structure according to claim 1, characterized in that: in, The number of blank substrate sheets shall not be less than 5.

3. The cylindrical battery negative electrode current collector structure according to claim 1, characterized in that: in, The middle and rear sections of the blank substrate are wound with no less than 5 turns.

4. A method for manufacturing a cylindrical battery negative electrode current collector structure as described in any one of claims 1-3, characterized in that, Includes the following steps: Step S1: Cut multiple notches at designated positions on the front section of the blank substrate on one side of the slit negative electrode plate to form multiple blank substrate sheets. Step S2: The negative electrode plate, positive electrode plate, and separator are wound into a core. During winding, the blank substrate sheet is pre-pressed towards the center of the core. The middle and rear sections of the blank substrate are kept vertical and wound into multiple turns. Step S3: Shape the pre-folded blank substrate sheet so that all the blank substrate sheets are folded down and overlap each other to form a current collector bottom wall at the center of the negative end of the core; and roll-shape the middle and rear sections of the blank substrate sheet that has been wound into multiple turns to form a current collector side wall. Step S4: Place the negative current collector into the space enclosed by the bottom wall and side wall of the current collector and press it tightly. Flip the negative current collector and weld it to the side wall of the current collector. Apply conductive adhesive to the holes of the current collector body. This completes the fabrication of the negative current collector structure of the cylindrical battery.

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