Packaging materials for electrochemical cells

Abstract

The present invention provides a packaging material for electrochemical cells having insulating properties capable of preventing short circuits, and excellent electrolytic solution resistance and water vapor barrier properties. The packaging material for electrochemical cells of the present invention is a packaging material for electrochemical cells in which a metal layer, an adhesive resin layer, and a thermally adhesive resin layer are laminated in sequence, and is characterized in that the metal layer and the adhesive There is a base film layer between the resin layers, and the base film layer contains at least: a zirconium oxide (A) having an average particle diameter in the range of 1 nm to 500 nm, and phosphorus oxides having 4 or more phosphonic acid groups per molecule. One or more phosphorus-containing compounds (B) and acid-modified polyolefin resins (C) among the compounds.

Description

technical field [0001] The present invention relates to a packaging material for an electrochemical cell, and particularly relates to a packaging material for an electrochemical cell having insulating properties capable of preventing short circuits, and excellent durability against an electrolytic solution and water vapor barrier properties. Background technique [0002] Lithium-ion batteries, also known as lithium secondary batteries, contain liquid, gel or polymer electrolytes and positive and negative active materials. Lithium-ion batteries include a lithium-ion battery body consisting of positive electrode current collector material / positive electrode active material layer / electrolyte solution layer / negative electrode active material layer / negative electrode current collector material, and an outer casing for packaging them. The outer casing is composed of a multilayer film The electrochemical cells are formed with packaging materials (hereinafter also simply referred to...

AI Technical Summary

Problems solved by technology

[0006] On the other hand, due to long-term use or rapid charging of the lithium ion battery 221, the lithium ion battery body 222 will emit heat, and a part of the thermal adhesive resin layer 215 in contact with the lithium ion battery body 222 will melt and fill the inside of the exterior body 220. The electrolyte solution permeates the metal layer 212, and sometimes a short circuit occurs between the lithium-ion battery body 222 and the metal layer 212

In addition, when heat-sealing the outer casing peripheral portion 220a, if a part of the separator included in the lithium ion battery body 222 or an electrode active material peeled off from the electrode enters the heat-sealed portion 220a, a part of the separator or the electrode active material peeled off from the electrode enters the heat-sealed portion 220a. The electrode active material is in contact with the metal layer 212, sometimes causing a short circuit

In addition, the metal terminal 224 extending from the lithium ion battery main body 222 to the outside of the exterior body 220 is sandwiched by the thermal adhesive resin layer 215 of the exterior body 220 in the state where the metal terminal 224 has burrs, and the outer body peripheral portion 220a is heated. In the case of sealing, a short circuit may sometimes occur between the metal terminal 224 and the metal layer 212

Images