Manufacturing method for coiled trapezoidal battery cell and trapezoidal battery cell

Abstract

The invention discloses a manufacturing method for a coiled trapezoidal battery cell and the trapezoidal battery cell. Intervals are formed between turning points of first to Nth circles of adjacent coiled materials of the trapezoidal battery cell; no intervals are formed between turning points of Nth to Mth circles of adjacent coiled materials; and the hotly pressed cross section of the battery cell is trapezoidal. The method comprises: during battery cell coiling, inserting a coiling needle when each of first to Nth circles is coiled, and increasing the coiling diameter of each circle by one expansion width relative to that of a previous circle, so that an interval is formed between the turning point of the nth circle of the coiled material and the turning point of the (n+1)th circle of the coiled material; completely coiling the residual coiled material by the fixed coiling diameter from the Nth circle to the Mth circle; and hotly pressing and shaping a coiled cell by adopting a clamp with a trapezoidal groove to obtain the battery cell with the trapezoidal cross section. The trapezoidal battery cell manufactured with the method can maximally use a reserved space of a device, so that the design capacity of the battery cell is increased; and the stress can be averagely distributed to the transitional oblique surface of the battery cell, so that the problem of deformation of the battery cell after long-term cycle can be avoided.

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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