Electrochemical characterization, structural evolution, and thermal stability of livopo₄ over multiple lithium intercalations

α₁-LiVOPO₄, β-LiVOPO₄, and α-LiVOPO₄ 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 LiVOPO₄ is similar to that of LiFePO₄ in the fully charged state from the results of the DSC profiles.