Lithium-ion battery anode pole piece and lithium-ion battery comprising the anode pole piece

Abstract

The invention belongs to the technical field of a lithium ion battery and particularly relates to a lithium ion battery anode pole piece. The lithium ion battery anode pole piece comprises a current collector, a first coating and a second coating, wherein the first coating is arranged on the surface of the current collector; the second coating is arranged on the surface of the first coating; the second coating comprises active materials; the active materials are at least one of graphite, silicon, silicon alloy and tin alloy; the first coating is a composite layer comprising an adhesive and a conductive additive; and the thickness of the first coating is 0.1mum to 5mum. The invention can solve the problem of stripping of a high gram volume anode membrane in the charging and discharging process without increasing the content of the adhesive in the anode membrane and can effectively prevent the expansion and stripping of the anode membrane in the repeated charging and discharging process of the battery on the premise of not influencing the dynamics performance of the battery, so that the safety and the reliability of the battery are improved when the high volume and the high energy density of the battery are implemented. Moreover, the invention also discloses a lithium ion battery comprising the anode pole piece.

Description

technical field [0001] The invention belongs to the technical field of lithium ion batteries, and in particular relates to an anode pole piece of a lithium ion battery and a lithium ion battery including the anode pole piece. Background technique [0002] Lithium-ion batteries are widely used in various consumer electronics products, various electric vehicles, and energy storage devices such as wind energy and solar energy because of their high energy density, long cycle life, excellent mechanical properties, and environmental friendliness. In recent years, people have higher and higher requirements for the energy density of batteries, which requires the anode materials used to have higher and higher gram capacities. Among various anode materials, graphite materials and silicon alloys have higher gram capacity. However, the anode material with a high gram capacity also brings about a large expansion problem during charging and cycling, and causes serious film removal proble...

AI Technical Summary

Problems solved by technology

The shedding of the diaphragm seriously affects the safety and reliability of the battery

[0003] For the traditional single-layer diaphragm, the charging expansion and release of silicon anode materials and alloy anode materials have not been solved. In order to solve this problem, we can greatly increase the binder content in the diaphragm to strengthen the diaphragm and set The bonding strength between the fluids is to resist the stress generated at the interface between the diaphragm layer and the current collector due to the expansion of the diaphragm layer during charging, but increasing the binder content will lead to a decrease in the active material content in the diaphragm and Reduction of diaphragm dynamics

[0004] In view of this, it is indeed necessary to provide a lithium-ion battery anode pole piece, which can solve the problem of swelling and defilming of the anode membrane that is prone to occur during the charging process of the battery without affecting the kinetic performance of the battery. Improve battery safety and reliability while achieving high battery capacity

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