Tin-cobalt alloy negative electrode material for lithium ion cell and its preparing method

Abstract

This invention involves the lithium ion battery tin cobalt alloy cathode material and the preparation method. The tin cobalt alloy cathode material at least includes Sn, Co3Sn2, CuSn or the CoSn3 two kind of materials, the surface has bud shape and the spherical two kind of shapes, the size is 5-50mum. Preparetion is that: 1) firstly attach a layer of tin on copper substrate; 2) prepare plating liquid: tin salt 10-50g / L, cobalt blue 5-20g / L, K4P2O73H2O100-400g / L, citric acid 10-30g / L, glycine 10-30g / L, methionine 2-10g / L; 3) use electric deposition method to control temperature at 15-35 degree C, pH = 8-9, the current density is 5-20mA / cm2, power on time is 0.5-2.5h, obtain the tin cobalt alloy material. This tin cobalt alloy is high in crystallization degree, not easy to have the serious reunion and the superficial oxidation, reduced the cathode material irreversible capacity.

Description

technical field [0001] The invention relates to the technical field of negative electrode materials for lithium ion batteries. In particular, the invention relates to a tin-cobalt alloy negative electrode material and a preparation method of a lithium ion battery. Background technique [0002] Lithium-ion battery is the latest generation of green high-energy rechargeable battery. It is a new power supply system developed rapidly in the early 1990s on the basis of lithium secondary battery research. It has high voltage, high energy density, good cycle performance, and self- Outstanding advantages such as small discharge and no memory effect. It has developed rapidly in the past 10 years, and has occupied a dominant position in the field of mobile electronic terminal equipment such as notebook computers, mobile phones, camcorders, and weapons and equipment with its excellent high performance and price ratio advantages. It is considered to be the key to the national economy in...

AI Technical Summary

Problems solved by technology

Although the tin oxide is due to the Li formed during the initial lithium intercalation 2 As a buffer matrix, O can well inhibit electrode expansion and improve electrode performance, but there is a problem of excessive irreversible capacity in the first cycle; while tin-based alloys adopt active / inactive or active / active structures, when intercalating and removing lithium Due to the buffering effect of other elements, it can effectively inhibit the expansion of the electrode and improve the cycle life of the electrode

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