Glass anode crystallization for high specific capacity Lithium-ion batteries

V2O5-TeO2 (VT) is one of the promising vanadium-based materials for electrodes in Li-ion batteries, but its application is impeded by its low conductivity and poor capacity retention. The initial cyclic efficiency of V2O5 -TeO2-Li2O(VTL) is enhanced by the addition of Li2O, implying that the pre-intercalation of Li-ions significantly improves the performance. The thermal treatment of VTL leads to the formation of V2O5 and Li1.2V9O22 crystals in the polycrystalline state (VTL-X). The VT, VTL and VTL-X exhibited specific capacitie of 821.9, 842.1, and 867.2 mAh g−1, respectively for the 1st cycle with respective retention rates of 19.6%, 19.5% and 27.5% after 1000 cycles. To elucidate the reaction mechanism, a structural simulation diagram of VTL during the heat treatment is modeled for the first time. The conversion of [VO5] to [VO4] transformed the structure of [TeO4] into [TeO3]. The DFT model reveals that the highest diffusion barriers for VTL and VTL-X are 0.49 eV and 0.16 eV, respectively. After crystallization, the conductivity and specific capacity of the resulting electrode material are significantly improved. LiV3O8 precipitated after 200 cycles promotes the reaction kinetics and specific capacity. The synergistic effect of precipitating crystals impacts the glass structure, electrochemical reversibility, and reaction kinetics enormously, revealing the pivotal function of nanocrystal in regulating the battery cycling stability. The formation mechanism of nanocrystals during cycling is entirely different from thermal induced crystallization. The crystallization of glass electrodes during battery cycles helps to unfold the properties of glassy materials.