Electrode assembly and lithium ion cell using the electrode assembly

Abstract

The present application relates to the field of energy storage devices, and in particular, to an electrode assembly and a lithium-ion battery cell using the electrode assembly. The electrode assembly includes a bare cell and a puncture-proof pad, the bare cell includes at least one electrode unit, the electrode unit includes a cathode electrode piece, an anode electrode sheet and a separator, wherein the cathode electrode sheet and the anode are The pole pieces are separated by the isolation film, and the anti-puncture pads are arranged on both sides in the width direction of the bare cell and cover the edges of the anode pole pieces. The lithium ion battery includes an aluminum-plastic film and the electrode assembly, and the aluminum-plastic film wraps the electrode assembly. The lithium ion battery provided by the present application can add a layer of protective isolation structure between the anode current collector and the aluminum-plastic film by arranging the anti-puncture cushion layer on the outside of the anode current collector on both sides of the bare battery core, which greatly reduces the It reduces the probability of the aluminum-plastic film being pierced by the pole piece.

Description

technical field [0001] The present application relates to the field of energy storage devices, in particular to an electrode assembly and a lithium-ion cell using the electrode assembly. Background technique [0002] With the development of science and technology, various electronic products emerge in an endless stream, almost becoming an indispensable part of daily life, and lithium-ion batteries have many advantages such as high energy density, long cycle life, environmental friendliness and reproducibility, etc. Used in various electronic products. [0003] Generally, a lithium secondary battery is formed by arranging an electrode assembly and an electrolytic solution in a battery case and sealing the battery case. An electrode unit used in an electrode assembly may be classified into a wrapping (winding) type, a stacked type, a folded type, etc. according to its structure. [0004] In related technologies, the polypropylene layer on the aluminum-plastic film is general...

AI Technical Summary

Problems solved by technology

On the one hand, the puncture strength of the thinned polypropylene layer decreases accordingly. On the other hand, because the lithium battery anode current collector is copper foil, and the process conditions in the related technology are limited, there will be burrs on the end surface of the copper foil. Under extreme conditions It may cause the burr on the anode end face to pierce the separator and the aluminum-plastic film, and in the laminated or stacked type lithium-ion cells, the edge of the thinned anode current collector will be sharper, thus exacerbating the anode current collector. Possibility of piercing the polypropylene layer of the aluminum-plastic film

[0005] If the polypropylene layer of the aluminum-plastic film is pierced, it will cause liquid leakage, and more seriously, it will cause the anode to be in contact with the aluminum foil layer of the aluminum-plastic film. Electrochemical reactions will cause corrosion at this position, which will also lead to liquid leakage and corrosion

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