Electrode plate and electrochemical device

Abstract

The invention relates to the field of batteries, in particular to an electrode plate and an electrochemical device. The electrode plate comprises a current collector and an electrode active material layer arranged on at least one surface of the current collector, wherein the current collector comprises a supporting layer and a conductive layer arranged on at least one surface of the supporting layer, the thickness D2 of a single surface of the conductive layer is greater than or equal to 30nm and less than or equal to 3mu m, the supporting layer is made of a high polymer material or a high polymer composite material, and the thickness D1 of the supporting layer is greater than or equal to 1mu m and less than or equal to 30mu m; wherein the electrode active material layer includes an electrode active material, a binder, and a conductive agent, and the coated electrode active material layer includes three regions based on a compaction density when viewed from a width direction of a coated surface of the electrode sheet, and a compaction density of a middle region is higher than compaction densities of both side regions. The electrode pole piece and the electrochemical device have high energy density and good electrical performance and safety.

Description

technical field [0001] The present application relates to the field of batteries, in particular, to an electrode sheet 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. With the continuous expansion of the application range of lithium-ion batteries, the requirements for the gravimetric energy density and volumetric energy density of lithium-ion batteries are also getting higher and higher. [0003] In order to obtain lithium-ion batteries with high mass energy density and volume energy density, lithium-ion batteries are usually improved as follows: (1) select positive electrode materials or negative electrode materials with high discharge specific capacity; (2) optimize the mechanical design of lithium-ion batteries , to minimize its volume; (3) select a positiv...

AI Technical Summary

Problems solved by technology

[0005] For pole pieces and batteries using metal-coated plastic current collectors, although the energy density is improved, it may cause some performance degradation in terms of processability and electrochemical performance.

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