Electrode pole piece and electrochemical device

Abstract

The present application relates to the field of batteries, in particular, to an electrode sheet and an electrochemical device. The electrode sheet of the present application includes a current collector and an electrode active material layer disposed on at least one surface of the current collector, wherein the current collector includes a support layer and a conductive layer disposed on at least one surface of the support layer, the The single-side thickness D2 of the conductive layer satisfies: 30nm≤D2≤3μm, the support layer is a polymer material or a polymer composite material, and the thickness D1 of the support layer satisfies: 1μm≤D1≤30μm; the electrode active material The layer includes an electrode active material, a binder and a conductive agent, and viewed from the width direction of the coated surface of the electrode sheet, the coated electrode active material layer includes three regions based on the compaction density, and the compaction of the middle region The solid density is higher than the compacted density of the side areas. The electrode pole piece and electrochemical device of the present application have high energy density, 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...

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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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