Positive pole piece and electrochemical device

Abstract

The invention relates to the field of batteries, in particular to a positive pole piece and an electrochemical device. The positive pole piece 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-side thickness D2 of the conductive layer meets the condition that D2 is larger than or equal to 30 nm and smaller than or equal to 3 microns, the conductive layer is made of aluminum oraluminum alloy, the density of the conductive layer is 2.5 g / cm<3> to 2.8 g / cm<3>, the electrode active material layer contains an electrode active material, a binder, and a conductive agent, and thebinder in the electrode active material layer has a non-uniform distribution in the thickness direction, and based on the total weight of the electrode active material layer, a weight percentage content of the binder in an inner region of the electrode active material layer is higher than a weight percentage content of the binder in an 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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