Electrode pole sheet and electrochemical device

Abstract

The invention belongs to the field of batteries and relates to an electrode pole sheet and an electrochemical device. The electrode pole sheet comprises a current collector and an electrode active material layer arranged on at least one surface of the current collector; the current collector comprises a supporting layer and a conductive layer arranged on at least one surface of the supporting layer; the single-surface thickness D2 of the conductive layer meets a relation that D2 is more than or equal to 30nm and less than or equal to 3 micrometers; the electrode active material layer comprisesan electrode active material, a binder and a conductive agent; the conductive agent in the electrode active material layer is non-uniformly distributed in a thickness direction; based on the total weight of the electrode active material layer, the weight percentage of the conductive agent in the inner side area of the electrode active material layer is higher than the weight percentage of the conductive agent in the outer side area of the electrode active material layer; and the conductive agent in the inner side area of the electrode active material layer contains an aqueous binder. The electrode pole sheet has good machinability; and the electrochemical device comprising the electrode pole sheet has high energy density, good electrical performance and long-term reliability.

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 processing performance, safety performance and electrical performance.

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