Tang Zilong group of Tsinghua University made another breakthrough in high rate lithium-ion battery materials

Recently, Professor Tang Zilong's research group of Tsinghua University School of materials published research results entitled "glass ceramic like high rate vanadate methods for high rate rate lithium ion batteries" in the Journal of advanced energy materials On the basis of the study of high power lithium titanate hydrate electrode materials, the problems of low volume energy density, low coulomb efficiency and rapid capacity attenuation of nano electrode materials were further solved
In lithium-ion batteries, nano electrode materials have the advantages of short-range ion diffusion distance and fast reaction kinetics, but the high specific surface area makes it easy to agglomerate particles and have serious side reactions with organic electrolyte in the process of electrode preparation and circulation; while micron electrode materials can effectively reduce the contact area with electrolyte and improve the compaction density, however, they have the following advantages: 1 The ability of ion diffusion is usually not enough to meet the needs of the rapid insertion and removal of ions in a short time Therefore, the above problems can be effectively solved by designing a kind of micron scale dense nanocrystalline material with both fast ion channel and low specific surface area Different from the traditional method of synthesizing nano micron materials from bottom to top, such as spray granulation and co precipitation self-assembly, the study adopted a top-down micron nano material synthesis strategy: first, the synthesis of micron vanadate precursors, and then introducing the glass ceramic phase in the low-temperature phase transition process, and simultaneously refining the grains Micron scale compact nanocrystalline electrode materials This kind of vanadate electrode material with glass like ceramic phase not only has rich grain boundary / phase interface to ensure the rapid transport of lithium ion, but also has a small specific surface area to reduce the surface side reaction with the electrolyte Based on the above advantages, the vanadate anode material has excellent electrochemical performance of large magnification, high capacity and long cycle This synthesis strategy is also universal for other transition metal oxide electrode materials whose precursor is hydrate, and provides a new idea for the design of micro nano structure in energy storage materials The corresponding authors of this paper are Professor Tang Zilong of Tsinghua University School of materials, Dr Wang Shitong and Dr Dong Yanhao of Massachusetts Institute of technology The first author is Li Yutong, a 2016 level doctoral student of Tsinghua University School of materials The research was supported by NSFC.