Copper foil composite material, preparation method thereof, negative pole piece and lithium ion battery

Abstract

The invention provides a copper foil composite material, a preparation method thereof, a negative pole piece and a lithium ion battery, and relates to the field of batteries. The copper foil composite material comprises a copper foil, and the surface of the copper foil is modified by an amino silane coupling agent. By utilizing the copper foil composite material, the problems that in the prior art, when a silicon-based material is used as a negative electrode active material, the capacity of the silicon-based material is rapidly attenuated in the early cycle and foil leakage occurs in the later cycle can be solved.

Description

technical field

[0001] The invention relates to the field of batteries, in particular to a copper foil composite material and a preparation method thereof, a negative pole piece and a lithium ion battery. Background technique

[0002] At present, in commercial lithium-ion batteries, the active material of the anode is mainly graphite. However, due to the limited mass specific capacity of graphite, there is little room for improvement in volume specific capacity. Lithium-ion batteries using graphite as the anode active material cannot meet the needs of future high-capacity, small volume / mass electronic devices.

[0003] Through research, it has been found that silicon is one of the most promising materials as an anode material for lithium-ion batteries. The theoretical gram capacity of silicon-based materials can be as high as 4200mAh / g, and the theoretical volume specific capacity can be as high as 7200mAh / cm 3 . However, during the delithiation / intercalation process of s...

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