Lithium battery winding core, lithium battery and manufacturing method

Abstract

The invention provides a lithium battery core, which includes at least two cylindrical core bodies and a long waist-shaped rim surrounding the at least two cylindrical core bodies; the cylindrical core body includes a positive electrode sheet and a positive electrode sheet respectively attached to the positive electrode. The negative electrode units on both sides of the sheet partially overlap at one end, and the negative electrode unit wraps the positive electrode sheet on the overlapping part; the negative electrode unit with the cylindrical core at one end in a free state surrounds all the cylindrical cores to form a perimeter. The advantage of the present invention is that two negative electrode units are wound around each other to form a cylindrical core, which has high manufacturing efficiency and good core consistency. It inherits the advantages of stable interface reaction of the cylindrical core and increases the efficiency by configuring several small-diameter assist cores. The heat dissipation area is enlarged and the defect of uneven internal temperature field is avoided. Multiple cylindrical cores are uniformly wound to form a long-waisted square core. The transition of the arcs at both ends is more uniform and the core structure is more compact. , effectively improving the energy density of lithium battery cores.

Description

technical field [0001] The invention relates to the technical field of lithium batteries, in particular to a lithium battery winding core, a lithium battery and a manufacturing method. Background technique [0002] At present, the winding cores of power lithium batteries are mainly square and cylindrical. The cross-section of the square core is elliptical. During the manufacturing process, it is necessary to overcome the variable tension movement of the pole piece and the diaphragm, which makes it difficult to correct the movement of the pole piece and the diaphragm, and the production efficiency is low. It is easy to cause the core to be scrapped due to internal short circuit. The arcs on both sides of the square core are easy to drop powder, and the chemical reaction interface is poor, which will seriously affect the energy performance of the lithium battery. The production process of cylindrical winding core is more mature, with high production efficiency and good consis...

AI Technical Summary

Problems solved by technology

[0004] The technical problem to be solved by the present invention is to provide a square and circular integrated winding core, so as to solve the problems of difficulty in rectifying the movement of the square winding core, easy short circuit, poor radial heat conduction of the circular winding core, and uneven internal temperature distribution.

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