a battery

Abstract

The invention relates to a battery, comprising a positive electrode sheet, a diaphragm, a negative electrode sheet and an electrolyte, wherein the positive electrode sheet includes a positive electrode current collector and at least two layers of positive electrode active material layers coated on at least one surface of the positive electrode current collector, The lower positive electrode active material layer in contact with the positive electrode current collector comprises the first positive electrode active material, the first polymer material and the first conductive material, based on the total weight of the lower positive electrode active material layer, the weight percentage of the first positive electrode active material is A%, the weight percentage of the first macromolecular material is B%, the weight percentage of the first conductive material is C%, and the upper positive electrode active material layer that is in contact with the lower positive electrode active material layer and away from the positive electrode current collector contains the second Two positive electrode active materials, the second polymer material and the second conductive material, based on the total weight of the upper positive electrode active material layer, the weight percentage of the second positive electrode active material is A '%, the weight percentage of the second polymer material The content is B'%, the weight percentage of the second conductive material is C'%, where A% <a′％，b％>B′%, C%≧C′%, and the first polymer material includes polyvinylidene fluoride and / or polyvinylidene chloride polymer material. The battery has good safety and improved electrical properties, and the normal temperature viscosity of the electrolyte is ≤4cp.< / a′％，b％>

Description

technical field [0001] The invention belongs to the technical field of electrochemistry, and more specifically, the invention relates to a battery. 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 provide a battery that can improve battery s...

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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