Method for preparing germanium-based cathode material for lithium ion battery by adopting carbothermic reduction method

Abstract

The invention relates to a method for preparing a germanium-based cathode material for a lithium ion battery by adopting a carbothermic reduction method. The method is characterized by comprising the following steps: 1, ball milling the mixture of germanium dioxide, graphite and coal asphalt in a weight ratio of 10: 7: 12 in an ethanol solution, and heating and extracting the ethanol solution to obtain a precursor of asphalt and graphite mixed carbon-cladding germanium dioxide; and placing the precursor prepared in the step 1 in a high-temperature furnace, heating the precursor at speed of 5 DEG C per minute in an argon atmosphere to 800 to 900 DEG C, sintering the precursor for 5h, and then naturally cooling the precursor. According to the method, the germanium oxide and carbon material are used as raw materials to be ball milled and sintered at 800 to 900 DEG C, and thorough carbothermic reduction is carried out on an electrochemical active substance GeO2 to form the germanium-graphite-carbon germanium-based cathode material. The method is simple in production step and low in production cost; the prepared material is good in coating effect, high in charging-discharging capacity retention rate and suitable for the commercialized mass production.

Description

technical field [0001] The invention belongs to the technical field of negative electrode materials for lithium ion batteries, and in particular relates to a method for preparing germanium-based negative electrode materials for lithium ion batteries by carbothermal reduction. Background technique [0002] In the 1990s, Sony used flaky graphite to replace the extremely unsafe metal Li, and successfully prepared the first rechargeable lithium-ion secondary battery. The scope has developed rapidly, and has expanded from mobile communication power supplies, notebook computers, cameras, etc. to power tools, electric vehicles and other fields. However, the electrochemical capacity of the existing carbon negative electrode is relatively low, which cannot meet the further requirements for the performance of portable secondary batteries due to technological development. [0003] As the fourth main group elements, Si, Sn, Ge, Pb, etc. all have certain electrochemical lithium intercal...

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Problems solved by technology

[0005] At present, the preparation steps of the known Ge-based negative electrode materials for lithium-ion batteries are cumbersome, and a considerable part of them are thin-film materials, which are difficult to scale up in production, and the cost is extremely high. Moreover, the capacity retention rate of the prepared materials is poor, and they all have different degrees of attenuation.

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