Understanding How Structure and Crystallinity Affect Performance in Solid-State Batteries Using a Glass Ceramic LiV₃O₈ Cathode

The rate-limiting step in lithiation/delithiation of solid-state cathode materials is not well understood. Phase-transformation reaction rate, lithium ion diffusion coefficient, and lithium ion concentration have all been shown to affect the discharge and charge performance. All three parameters are affected by the crystal structure and crystallinity of the cathode. In this paper, lithium trivanadate (LiV₃O₈) is selected as a representative cathode for all solid-state thin-film batteries because of its glass ceramic properties at different annealing temperatures, where the crystallinity and preferred orientation vary. The intermediate temperature-treated thin films outperform both the amorphous and the most crystalline thin films. By correlating the cell polarization with both the diffusion coefficient and the lithium ion concentration at different states of charge, we gain insights into the electrochemical performance of the glass ceramic LiV₃O₈ cathode.