Preparation method of wound trapezoidal cell and trapezoidal cell

Abstract

A preparation method of a wound trapezoidal battery core and the trapezoidal battery core, in the trapezoidal battery core, intervals are formed between the inflection points of the 1-Nth circles of adjacent coils, and the inflection points of the N-M circles of adjacent coils are There is no space between them, and the cross-sectional shape of the cell after hot pressing is trapezoidal. When the battery core of the present invention is wound, from the first turn to the Nth turn, a piece of winding needle is inserted for each turn, so that the winding diameter of each turn is increased by an expansion width relative to the winding diameter of the previous turn, so that There is an interval between the inflection point of the nth coil and the n+1 coil; from the Nth coil to the Mth coil, the remaining coil is wound with a fixed winding diameter; the trapezoidal groove is used The jig heat-presses and shapes the winding core, and after hot-pressing and shaping, a battery core with a trapezoidal cross-sectional shape is obtained. The trapezoidal battery cell obtained by the present invention can maximize the reserved space for the use of equipment, increase the design capacity of the battery cell, and can evenly distribute the stress on the transition slope of the battery cell, and can avoid the problem of deformation of the battery cell after long-term cycling.

Description

technical field [0001] The invention belongs to the technical field of polymer lithium ion battery manufacturing, and in particular relates to a preparation method of a wound lithium ion battery core and the lithium ion battery core. Background technique [0002] At present, communication and digital products have a variety of shapes. In order to adapt to the shape of the product, the space for storing batteries is not necessarily a square hexahedron, such as a cuboid or cube, but may also be a polyhedron with a trapezoidal cross-sectional shape. If ordinary rectangular batteries are still used in special-shaped spaces, there will be the following disadvantages: 1. Rectangular batteries cannot make full use of the reserved space for storing batteries, resulting in low design capacity of batteries and short standby time of equipment; 2. Due to the The outside of the cell is a rectangular body inscribed in the trapezoidal space, and only the two sides of the cell are in contac...

AI Technical Summary

Problems solved by technology

If ordinary rectangular batteries are still used in special-shaped spaces, there will be the following disadvantages: 1. Rectangular batteries cannot make full use of the reserved space for storing batteries, resulting in low design capacity of batteries and short standby time of equipment; 2. Due to the The outside of the cell is a rectangular body inscribed in the trapezoidal space, and only the two sides of the cell are in contact with the inner surface of the storage space, there is a risk of shaking or overvoltage on the side of the battery

The stepped roll shape can solve the aforementioned problems to a certain extent, but because the stepped core still cannot maximize the space reserved for the use of the product and fit perfectly with the side of the storage space, and the stress at the step transition of the stepped cell is very high. Large, easy to deform after long-term circulation, posing safety hazards

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