Positive plate and lithium ion battery

Abstract

The invention provides a positive plate and a lithium ion battery. The invention provides a positive plate in the first aspect. The positive plate comprises a positive current collector, a first positive active layer and a second positive active layer, wherein the first positive active layer and the second positive active layer are sequentially stacked on at least one surface of the positive current collector; the thickness of the first positive electrode active layer is greater than or equal to 10% of the total thickness of the positive electrode active layer, the first positive electrode active layer comprises a non-active material, and the porosity of the first positive electrode active layer is smaller than that of the second positive electrode active layer. According to the lithium ion battery, the first positive active layer is filled with the non-active material, so that the chance of contact between the positive current collector and the negative active layer is reduced, contact short circuit of the lithium ion battery during abuse such as needling and extrusion is prevented, the safety of the lithium ion battery is improved, meanwhile, the second positive active layer is not changed, and the service life of the lithium ion battery is prolonged. And the energy density of the lithium ion battery is effectively considered.

Description

technical field [0001] The present application relates to a positive electrode sheet and a lithium ion battery, and relates to the technical field of batteries. Background technique [0002] Lithium-ion batteries are widely used in smart phones, notebook computers, Bluetooth, wearable devices and other fields due to their high platform voltage, high energy density, no memory effect, and long life, and play an important role in people's lives. . However, when the lithium-ion battery is abused, especially when mechanical abuse such as acupuncture occurs, the positive and negative electrodes of the lithium-ion battery are short-circuited, which will instantly generate a large amount of heat, causing thermal runaway of the lithium-ion battery. [0003] There are four short-circuit modes in the positive electrode and the negative electrode. The contact heat generation of the anode active layer is the most severe, and it is the short-circuit mode that is most likely to cause the...

AI Technical Summary

Problems solved by technology

However, when lithium-ion batteries are abused, especially when mechanical abuse such as acupuncture occurs, the positive and negative electrodes of the lithium-ion battery will short-circuit in contact, which will instantly generate a large amount of heat, causing thermal runaway of the lithium-ion battery.

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