Electrochemical Characterization, Structural Evolution, and Thermal Stability of LiVOPO_4 over Multiple Lithium Intercalations

α1-LiVOPO_4, β-LiVOPO_4, and α-LiVOPO_4 are known as multiple lithium intercalation cathode materials. They were characterized by means of half-cell performance, operando X-ray diffraction (XRD), X-ray absorption spectroscopy (XAS), and differential scanning calorimetry (DSC). The operando XRD revealed differences in crystal structure evolution during charging/ discharging among the three crystal phases. Although the charge/discharge profiles and the crystal structure evolution behaviors were the same among the three crystal phases in the range of 3.5 - 4.5 V, the profiles and behaviors differed completely in the range of 1.0 - 3.5 V. The thermal stability of each phase of LiVOPO_4 is similar to that of LiFePO_4 in the fully charged state from the results of the DSC profiles.