Current collector and pole plate thereof, and electrochemical device

Abstract

The present application relates to the field of batteries, and in particular, to a current collector and a pole piece thereof, and an electrochemical device. The current collector comprises an insulating layer and a conductive layer, wherein the conductive layer is positioned on at least one surface of the insulating layer, the thickness of the conductive layer is D2, and D2 satisfies the following inequation: 30nm<=D2<=3 [mu]m; the current collector is internally provided with a plurality of holes penetrating the insulating layer and the conductive layer. The current collector can improve the short-circuit resistance of the battery in the case of short circuit under the abnormal condition, so that the short-circuit current is greatly reduced, the short-circuit heat production is greatly reduced, and the safety performance of the battery is improved; the plurality of holes arranged in the current collector can facilitate pass of the electrolyte, can reduce the polarization of the pole plate and the battery and can improve the electrochemical performance of the battery; and moreover, the holes arranged in the current collector can further reduce the weight of the current collector and can improve the weight energy density of the battery.

Description

technical field [0001] The present application relates to the battery field, in particular, to a current collector, its pole piece and an electrochemical device. Background technique [0002] Lithium-ion batteries are widely used in electric vehicles and consumer electronics due to their advantages such as high energy density, high output power, long cycle life and low environmental pollution. However, when lithium-ion batteries are subjected to abnormal conditions such as extrusion, collision or puncture, they are prone to fire and explosion, causing serious hazards. Therefore, the safety problems of lithium-ion batteries have largely limited the application and popularization of lithium-ion batteries. [0003] A large number of experimental results show that the short circuit in the battery is the root cause of the safety hazard of lithium-ion batteries. In order to avoid short circuits in the battery, researchers have tried to improve the structure of the separator, the...

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Problems solved by technology

[0005] However, these methods in the prior art cannot effectively prevent the occurrence of a short circuit in the lithium-ion battery, and there is no guarantee that the battery can continue to work after the abnormal situation occurs.

In the above-mentioned improved methods, after the internal short circuit occurs in the battery, the battery temperature will still rise sharply. When the battery temperature rises suddenly, if the safety components cannot respond quickly, there will still be different degrees of danger; and in the above-mentioned improvements In the method, after the safety component responds, although the potential safety hazard of the battery is resolved, the battery cannot continue to work

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