A winding battery

Abstract

The present application relates to the field of secondary batteries, in particular, to a winding battery core. The wound-type electric core of this application is a flat electric core formed by stacking and winding the first diaphragm, the first pole piece, the second diaphragm and the second pole piece in sequence, and the head of the first pole piece is empty. The foil area is electrically connected to the first tab, and the head of the second pole piece is an empty foil area and is electrically connected to the second tab; the center line of the flat cell in the width direction is the center line of the cell, and the first pole The point where the piece is bent for the first time is the first bending point, the line passing through the first bending point and parallel to the center line of the battery core is the first bending line, and the starting end of the first pole piece is the first starting end; The starting end of a diaphragm and the starting end of the second diaphragm are located between the first starting end and the second tab, and the distance from the first starting end to the first bending line is smaller than the distance from the second tab to the first bending line. The wound electric core of the present application can save the amount of separator, increase energy density, and reduce cost.

Description

technical field [0001] The present application relates to the field of secondary batteries, in particular, to a winding battery core. Background technique [0002] At present, secondary batteries widely used in the market are composed of battery cells and casings of secondary batteries. Among them, the battery core is an active component, and is generally formed by laminating or winding a positive pole piece, a negative pole piece, and a separator arranged between the positive pole piece and the negative pole piece. The positive electrode sheet includes a positive electrode collector and a positive electrode active material coated on the surface of the positive electrode collector; the negative electrode sheet includes a negative electrode collector and a negative electrode active material coated on the surface of the negative electrode collector. [0003] With the development of commercialization of secondary batteries, the market has higher and higher requirements for the...

AI Technical Summary

Problems solved by technology

However, these solutions are currently limited by the material itself or processing, and further improvement is becoming more and more difficult, and may bring high costs or high risks.

[0004] In the current traditional winding method, such as figure 1 and figure 2 As shown, the inside of the winding cell needs to be empty with a layer of isolation film. There are 4 layers of isolation film stacked continuously on the innermost side of the cell, which not only causes waste of the isolation film, but also increases the thickness of the cell to reduce the energy density of the cell.

Images