A positive pole piece and electrochemical device

Abstract

The present application relates to the field of batteries, in particular, to a positive electrode sheet and an electrochemical device. The positive 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 thickness D2 of one side of the conductive layer satisfies: 30nm≤D2≤3μm, the material of the conductive layer is aluminum or aluminum alloy, and the density of the conductive layer is 2.5g / cm 3 ~2.8g / cm 3 , the electrode active material layer includes an electrode active material, a binder and a conductive agent, and the binder in the electrode active material layer has a non-uniform distribution in the thickness direction, wherein based on the total weight of the electrode active material layer , the weight percent of the binder in the inner region of the electrode active material layer is higher than the weight percent of the binder in the outer region of the electrode active material layer.

Description

technical field [0001] The invention belongs to the technical field of electrochemistry, and more specifically, the invention relates to a positive pole piece 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. 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] Although researchers have proposed many methods to improve the safety of batteries, there is still a lack of very effective means for the potential safety hazards caused by battery punctures. In view of this, it is indeed necessary to pr...

AI Technical Summary

Problems solved by technology

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 harm

Therefore, the safety problems of lithium-ion batteries have largely limited the application and popularization of lithium-ion batteries.

[0003] Although researchers have proposed many methods to improve the safety of batteries, there is still a lack of very effective means for the potential safety hazards caused by battery punctures.

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