| CPC H01M 50/536 (2021.01) [H01M 10/0585 (2013.01); H01M 50/54 (2021.01); H01M 10/052 (2013.01)] | 4 Claims |
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1. A method for welding and converging battery cell tabs, used for welding and converging positive and negative tabs after forming a plate set by battery laminating, wherein the method comprises:
laminating to form plate sets each composed of a positive plate, a separator and a negative plate by laminating, wherein the positive plate comprises a positive tab, and the negative plate comprises a negative tab;
wherein,
the method further comprises: bending the positive tab to form a positive tab bend; and/or, bending the negative tab to form a negative tab bend, wherein the positive tab bend has a straight section and a bent section, the straight section is formed by extending the positive plate, and the bent section is used for forming the positive tab bend; and the negative tab bend has a straight section and a bent section, the straight section is formed by extending the negative plate, and the bent section is used for forming the negative tab bend;
converging the plate sets, wherein a plurality of positive tabs of the plurality of plate sets are laminated to form a positive tabs laminated structure, a stress exists between adjacent positive tab bends in the positive tabs laminated structure, and the positive tabs laminated structure forms a stressed entirety under actions of the stress and an elastic force generated by deformation of the plurality of positive tabs; and/or, a plurality of negative tabs of the plurality of plate sets are laminated to form a negative tabs laminated structure, a stress exists between adjacent negative tab bends in the negative tabs laminated structure, and the negative tabs laminated structure forms a stressed entirety under actions of the stress and an elastic force generated by deformation of the plurality of negative tabs; and,
welding a plurality of positive tab bends in the plate sets, wherein the welded positive tab bends are directly welded to a cell case; and/or, welding a plurality of negative tab bends in the plate sets, wherein the welded negative tab bends are directly welded to the cell case;
wherein, a coordinate system is established along a length direction of the tab as an x axis and a direction perpendicular to the tab as a y axis, and a projection contour line of a curved surface on which the tab is located on an xy plane is represented by y=f(x), a length of a bent part of the tab is calculated by the following formula:
L=∫ab√1+(f′(x))2dx
wherein upper and lower limits a and b of the integral represent a value range of the x axis of the contour line of the tab;
the bending the positive tab to form the positive tab bend; and/or, bending the negative tab to form the negative tab bend comprises:
transferring the plate set formed by laminating to a converging member;
laminating the plurality of plate sets on the converging member, wherein the plurality of positive tabs of the plate sets or the plurality of negative tabs of the plate sets form the positive tabs laminated structure or the negative tabs laminated structure, respectively; and
bending the positive tabs laminated structure formed by the plurality of positive tabs to form the laminated positive tab bends, and/or bending the negative tabs laminated structure formed by the plurality of negative tabs to form the laminated negative tab bends;
the converging member has a C-shaped structure, and the plate sets are transferred to the converging member along a side opening of the C-shaped structure,
or, the converging member has a U-shaped structure, and the plate sets are transferred to the converging member along an upper opening of the U-shaped structure.
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