Current collector, pole sheet and electrochemical device

Abstract

The application belongs to the field of batteries and relates to a current collector. The current collector includes an insulating layer and a conducting layer, wherein the conductive layer is positioned on at least one surface of the insulating layer; the current collector further comprises a first protective layer arranged on a surface, far away from the insulating layer, of the conducting layer; a plurality of holes penetrating through the insulating layer, the conducting layer and the first protective layer are formed in the current collector; and the first protective layer is a metal oxide protective layer. According to the current collector provided by the invention, short-circuit resistance during a short circuit under the abnormal condition of a battery can be improved, so that heat generated the short circuit can be greatly reduced, and therefore, the safety performance of the battery is improved; the mechanical strength of the conductive layer can be improved through the protective layer; the working stability of the current collector is improved; the service life of the current collector is prolonged; the plurality of holes penetrating through the insulating layer and the conductive layer can facilitate the passage of electrolyte, and therefore, the wettability of the electrolyte can be improved, and the electrochemical performance of the battery and the weight energy density of the battery can be improved.

Description

technical field [0001] The present application relates to the field of batteries, in particular, to a current collector, a pole piece and an electrochemical device. Background technique [0002] Lithium-ion batteries are widely used in electric vehicles and consumer electronics products 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, it is easy to catch fire and explode, causing serious harm. Therefore, the safety problem of lithium-ion batteries limits the application and popularization of lithium-ion batteries to a great extent. [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 the short circuit in the battery, researchers have tried to improve the structure of 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 improved methods, after the internal short circuit occurs in the battery, the temperature of the battery will still rise sharply. When the temperature of the battery rises suddenly, if the safety components cannot respond quickly, there will still be different degrees of danger; 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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