High-energy density pole piece and production method thereof

Abstract

The invention provides a high-energy density pole piece which comprises a current collector, a first active substance layer and a second active substance layer. The first active substance layer and the second active substance layer are arranged on two sides of the current collector, the first active substance layer is formed by pressing a pole group, and the current collector is formed by vacuum evaporation of metal on one side of the first active substance layer. And the second active substance layer is formed by coating a slurry on one side, far away from the first active substance layer, ofthe current collector and drying. The interface structures of the current collector, the first active substance layer and the second active substance layer are compact and high in binding force, active substances can be effectively prevented from falling off, a problem that the binding force between an existing current collector and the active substances is poor is solved, an interface impedanceis reduced, and the electrical performance and the safety performance of a lithium ion battery are effectively improved.

Description

technical field [0001] The invention relates to the technical field of lithium batteries, in particular to a pole piece with high energy density and a preparation method thereof. Background technique [0002] With the rapid development of lithium-ion batteries, people have higher and higher requirements for lithium-ion batteries, not only including the rapid increase in demand for lithium-ion batteries, but also higher requirements for the lightweight and energy density of lithium-ion batteries. requirements. For the lightweight and energy density of lithium-ion batteries, in addition to using lighter materials and higher-capacity electrode materials and electrolytes, the above requirements can also be met by optimizing the electrode structure. [0003] The electrode structure consists of a current collector and positive or negative active materials carried on both sides of the current collector. The positive and negative active materials are the donors and acceptors for li...

AI Technical Summary

Problems solved by technology

However, the preparation and application of the existing pole pieces still face some technical problems: (1) During the charging and discharging process, due to the limited strength of the binder, the interface between the current collector of the pole piece and the active material is poorly bonded, and the active material It is easy to fall off from the current collector, and at the same time, the contact area between the surface of the current collector and the active material is small, and the interface resistance is large, which makes the performance of the battery deteriorate and the safety is reduced, thereby affecting the performance of the battery; (2) The current collector usually uses conductive metal sheets, such as Aluminum foil or copper foil, etc. Due to the limitations of the preparation technology of the current commercial aluminum foil and copper foil, it is difficult to reduce the thickness of the positive and negative current collectors.

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