Lithium zirconate/tungstate-carbon '[Li2ZrO3]x[Li2WO4]1-x-C' lithium ion battery anode material and preparation method thereof

Abstract

The invention discloses a lithium zirconate / tungstate-carbon '[Li2ZrO3]x[Li2WO4]1-x-C' (x is a number ranging from 0.01 to 0.99) lithium ion battery anode material and a preparation method thereof. The preparation method adopts a dispersing agent to enable [Li2ZrO3]x[Li2WO4]1-x and carbon to be fully contacted, and a lithium battery anode material with high conductivity, high charge-discharge current density, high charge-discharge cycling stability and high capacity is prepared.

Description

technical field [0001] The invention relates to a lithium ion battery negative electrode material with high capacity and a preparation method thereof; more particularly, the invention relates to a composite electrode material of lithium zirconate tungstate and carbon for lithium ion batteries and a preparation method thereof. Background technique [0002] At present, due to the high Coulomb capacity of carbon materials (graphite theoretical value 372mAh / g, actual value 300-350mAh / g), lower production cost and longer cycle life [Wu, Y.P.; Rahm, E.; Holze, R. Carbon AnodeMaterials for Lithium Ion Batteries. J. Power Sources 2003, 114, 228; Marom, R.; Amalraj, S.F.; Leifer, N.; Jacob, D.; .Mater.Chem.2011, 21, 9938], lithium-ion batteries generally use hard carbon, soft carbon and graphite as negative electrode materials. However, due to the low crystallinity of hard carbon and soft carbon, although it can be charged quickly, it is difficult to use on a large scale due to the ...

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Problems solved by technology

The material is fired under Ar atmosphere at 750 degrees. The material is actually coated with carbon. Since carbon is amorphous carbon, the conductivity of the material is not ideal, and the stability is poor.

Other vanadium-containing negative electrode materials include carbon-coated Li 3 VO 4 Materials and the carbon-coated Li disclosed in CN20130237355.8 3 VO 4 materials, all have poor conductivity of amorphous carbon, and the nano-carbon coating layer is due to Li 3 VO 4 The volume expansion of the material leads to the destruction of the cladding layer, and the Li 3 VO 4 The material particles are in contact with each other, the conductivity becomes poor, and the charge and discharge capacity of the material decreases

[0005] Li 2 MoO 4 and Li 2 WO 4 with Li 3 VO 4 Similar to Li 2 MoO 4 (capacity of 769mAh / g when transporting 5 electrons and 5 lithium ions) and Li 2 WO 4 (When transporting 5 electrons and 5 lithium ions, the capacity is 510mAh / g) are potential high-capacity negative electrode materials, but due to the poor conductivity of these materials, they cannot be charged quickly, and the first charge and discharge efficiency is low and the decay is fast. , so it cannot be directly used as electrode material

Yanming Zhao (Electrochimica Acta 174 (2015) 315-326) and (X. Liu, Y. Zhao, Y. Lyu, Z. Zhang, H. Li, Y. Hu, Z. Wang, Q. Kuang, Y. Dong , Z.Liang, Q.Fan and L.Chen, Nanoscale, 2014, DOI: 10.1039 / C4NR04226C.) reported Li 2 MoO 4 Nanorod and nanotube anode materials, the first charge and discharge efficiency is only about 30%, the stable capacity is lower than 200mAh / g and decays quickly, after the Li is coated with carbon generated by the decomposition of organic matter 2 MoO 4 Nanorod and nanotube anode materials will perform better, with a capacity of 670mAh / g and an initial charge and discharge efficiency of about 64%, but they still decay quickly. On the one hand, the carbon generated by the decomposition of organic matter at low temperature is amorphous carbon. The electrical conductivity and the first charge and discharge efficiency of itself are poor. In addition, because the coated carbon layer is too thin, it is easy to destroy the carbon coating layer and destroy the Li when the volume changes. 2 MoO 4 nanorods and nanotubes, making Li 2 MoO 4 Nanorods and nanotubes agglomerate into non-conductive inorganic salts and lose activity

, although the weight capacity of the material seems to be very high (670mAh / g), the specific gravity of nanomaterials is small and the volumetric energy density (capacity) is very low, which has no practical value