Electrode pole piece, electrochemical device and safety coating

Abstract

The invention relates to an electrode piece, an electrochemical device and a safety coating. The electrode includes a current collector, an electrode active material layer and the safety coating arranged between the current collector and the electrode active material layer, wherein the safety coating includes polyvinylidene fluoride and / or polyvinylidene macromolecule primary body, a conductive material, an inorganic filler and water-based binder. A circuit can be cut off by the electrode pole piece when the electrochemical device (such as a capacity, one-time battery and second-time battery)is subjected to high temperature conditions or internal short circuit happening, so that high temperature safety of the electrochemical device is improved.

Description

technical field [0001] The invention belongs to the technical field of electrochemistry, and more specifically, the invention relates to an electrode pole piece and an electrochemical device including the electrode pole piece. 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 the short circuit in the battery, r...

AI Technical Summary

Problems solved by technology

However, in this improved mode, when the active material slurry is coated on the surface of the PTC material layer, the solvent in the slurry (such as NMP, etc.) will dissolve the PTC material in the PTC layer and enter the upper active material layer, not only Make the PTC layer lose the PTC effect, and it will deteriorate the electrical performance

In addition, during the compaction step in the pole piece manufacturing process, the PTC material layer is easily squeezed to the edge, resulting in direct contact between the electrode active material layer and the current collector, thus losing the effect of improving safety performance

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