Positive current collector, positive pole piece and electrochemical device

Abstract

The present invention discloses a positive electrode current collector, a positive electrode sheet and an electrochemical device. The positive electrode current collector comprises: a support layer having two opposite surfaces in the thickness direction thereof; and a conductive layer disposed on at least one of the two surfaces of the support layer; wherein the thickness D1 of the conductive layer is greater than or equal to 300nm and less than or equal to 2mu m, and preferably, the thickness D1 is greater than or equal to 500nm and less than or equal to 1.5 mu m; and when the tensile strainof the positive electrode current collector is 1.5%, the square resistance growth rate T of the conductive layer is less than or equal to 30%. The positive electrode current collector provided by theinvention can give consideration to relatively high safety performance and electrical performance at the same time, so that the positive electrode piece and the electrochemical device adopting the positive electrode current collector can give consideration to relatively high safety performance and electrochemical performance at the same time.

Description

technical field [0001] The invention belongs to the technical field of electrochemical devices, and in particular relates to a positive electrode current collector, a positive electrode sheet and an electrochemical device. Background technique [0002] Due to the advantages of high energy density, high output power, long cycle life and low environmental pollution, lithium-ion secondary batteries are widely used in electric vehicles and consumer electronics products. However, when the lithium-ion secondary battery is subjected to abnormal conditions such as nail penetration, it is easy to cause a short circuit in the battery. At this time, the battery generates a large current and is accompanied by a large amount of heat generated by the short circuit, which is likely to cause the battery to smoke, catch fire, or even explode. Security risks. [0003] In the prior art, separators with high puncture strength are used to avoid internal short circuits in batteries, or the hazar...

AI Technical Summary

Problems solved by technology

However, the existing technology cannot effectively control the internal short circuit and short circuit heat generation of the battery, and the safety of the battery cannot meet the increasingly high requirements of the market.

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