Positive plate and lithium ion battery comprising positive plate

Abstract

The invention provides a positive plate and a lithium ion battery comprising the positive plate. The positive plate comprises a positive current collector and a positive coating, and the positive coating comprises a first coating and a second coating. The surface of the positive electrode current collector is coated with the first coating, and the surface of the first coating is coated with the second coating; the first coating comprises an inorganic filler, a first conductive agent and a first binder, and the second coating comprises a positive active material, a second conductive agent and asecond binder. When the relationship X<1> / (Y<1>*SY<1>+Z<1>*SZ<1>) > X<2> / (Y<2>* SY<2>+Z<2>*SZ<2> is satisfied, the lithium ion battery has good safety performance, and the probability of fire failureof the battery is greatly reduced when mechanical abuse (acupuncture and heavy impact) occurs. And meanwhile, the cycle performance of the lithium ion battery is not influenced and is equivalent to the cycle performance effect of the existing lithium ion battery, namely, the safety performance of the lithium ion battery is remarkably improved on the premise of keeping the cycle performance of thelithium ion battery.

Description

technical field [0001] The invention belongs to the technical field of lithium ion batteries, and in particular relates to a positive electrode sheet and a lithium ion battery including the positive electrode sheet. Background technique [0002] Lithium-ion batteries are widely used in smartphones, laptops, Bluetooth, wearable devices and other fields due to their advantages such as high platform voltage, high energy density, no memory effect, and long life. However, in some extreme cases, such as when the lithium-ion battery is subjected to mechanical damage (needle puncture, heavy impact, etc.), an internal short circuit will occur, and a lithium-ion battery with an internal short circuit will emit a large amount of heat in a short period of time, causing the battery Failure to catch fire has a great potential safety hazard. [0003] Studies have found that when an internal short circuit occurs in a lithium-ion battery, there will be multiple short-circuit modes, among wh...

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Problems solved by technology

[0004] The present invention provides a positive electrode sheet and a lithium ion battery including the positive electrode sheet. The use of the positive electrode sheet can solve the problems of lithium ion battery fire and failure in the case of mechanical abuse, and improve the safety performance of the lithium ion battery. At the same time, the The cycle performance of lithium-ion batteries is not affected, which is equivalent to that of existing lithium-ion batteries, that is, the safety performance of lithium-ion batteries is significantly improved while maintaining the cycle performance of lithium-ion batteries

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