Electrochemistry of lithium trivanadate (LiV3O8, LVO) has been extensively studied due to its large capacity and high rate capability. The material undergoes both insertion/extraction and phase transform reactions during discharge and charge in a Li-ion battery. However, the rate limiting factors of the material are unclear over the cycling window of 2.0 -3.8 V. In this work, LVO thin films are fabricated from RF magnetron sputtering and annealed at different temperatures of 260, 350, 400 and 500°C. Crystallinity, crystallite size and preferred orientation of the thin films are analyzed by x-ray diffraction. All solid-state thin film batteries are fabricated with LVO cathodes annealed at different temperatures of 260, 350 and 400°C. The electrochemical properties are investigated at two different test temperatures to compare the rate limiting process for discharge and charge. AC impedance is applied on the 260 and 350°C cells to characterize the voltage dependence of the diffusion coefficient during both discharge and charge. Our work correlates the cell polarization with both the diffusion coefficient and the Li+ concentration, showing that these parameters play different roles in the insertion and phase transform reactions, and shows the structural dependence of these parameters. Figure 1