Phase structure and thermodynamic properties of lithium metavanadate (LiVO₃)

Lithium metavanadate (LiVO 3 ) has emerged as a promising cathode material for lithium‐ion batteries, requiring a deep understanding of its phase structure, stability, and thermodynamic properties. In this study, the LiVO 3 sample was characterized using X‐ray diffraction and X‐ray photoelectron spectroscopy. The molar heat capacity ( C p ) of the monoclinic LiVO 3 phase for temperatures ranging from 2 to 298.15 K was experimentally determined through a physical properties measurement system, and the third‐law entropy at 298.15 K was derived as 99.27 ± 4.47 J mol −1 K −1 . Enthalpy changes at elevated temperatures are determined using a Calvet‐type calorimeter. The experimental C p values are slightly lower than those predicted based on the Neumann‒Kopp rule in the temperature ranges investigated. Besides, the enthalpies of formation of LiVO 3 from oxides and elements reference are determined to be ‒129.92 ± 1.41 kJ mol −1 and ‒1204.17 ± 2.46 kJ mol −1 by performing high‐temperature oxide melt solution calorimetry, respectively. The systematic trend on the thermodynamic properties for all alkali metavanadates RVO 3 (R = Li, Na, K, Rb, and Cs) is observed, which can be further used to predict thermodynamic properties with unknown reliable experimental values. The thermodynamic properties obtained in this study offer valuable insights into the design and synthesis of LiVO 3 cathode materials.