Method for manufacturing fast-charging long-circulating graphite negative pole piece

Abstract

The invention discloses a method for manufacturing a fast-charging long-circulating graphite negative pole piece, which comprises the steps of 1) crushing petroleum coke, 2) mixing petroleum coke particles, a high-temperature asphalt binder and stearic acid, 3) carrying out multi-stage temperature coating and bonding, 4) cooling to the room temperature, 5) adding Fe3O3 for graphitization treatment, 6) coating a nano Fe3O4 ionic liquid and carrying out magnetization treatment; and 7) drying to obtain the finished product. The method not only can improve the graphitization degree, greatly reducethe graphitization temperature of various amorphous carbons and improve the first charge-discharge efficiency and circulation stabilization of a graphite negative pole material, but also coats magnetic nanoparticle Fe3O4 on the surface, carries out the magnetization treatment and greatly reduces the OI value of the pole piece.

Description

technical field [0001] The invention relates to the field of graphite production for lithium-ion battery negative electrode materials, in particular to a method for producing fast-charging and long-cycle graphite negative electrode sheets. Background technique [0002] At present, the main anode materials for lithium-ion batteries are as follows: graphitized carbon materials, nitrides, silicon-based materials, tin-based materials, and new alloys. There are only two types of lithium-ion battery anodes that are commercialized on a large scale, which is graphite. Carbon-like materials and lithium titanate (LTO). [0003] Graphite material has good electrical conductivity, high crystallinity, and good layered structure, which is suitable for lithium intercalation-deintercalation. The discharge specific capacity can reach more than 300mAh / g, the charge-discharge efficiency is above 90%, and the irreversible capacity is less than 50mAh / g. g. Focusing on the future, the developme...

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Problems solved by technology

[0006] 3. The existing negative electrode sheets of lithium-ion batteries cannot arrange graphite end faces, so the only way to reduce the OI value (D002 / D110) of the negative electrode sheet is through secondary particle granulation. During the process, the OI value increases again, so that lithium ions cannot be well transmitted in the graphite of the negative electrode sheet

The nano-growth method can well grow the active material on the surface of the negative electrode substrate, but the method is complex and costly, difficult to control, and difficult to apply on an industrial micron scale

The negative electrode slurry is easy to introduce other metal ion impurities in the process of mixing and filtering, and it is difficult to remove them in the subsequent process, which will affect the charge and discharge and cycle performance of the battery cell.

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