Pressure-induced phase transition toward high symmetry in zero-strain LiTiO

As a typical layered oxide material, Li 2 TiO 3 has attracted considerable attention in the energy revolution and military industries, owing to its lithium-rich and "zero-strain" characteristics. However, its phase-transition behavior under high pressure remains unclear. Herein, we report a second-order phase transition from the monoclinic phase to a higher-symmetry phase in nano-polycrystalline Li 2 TiO 3 at 43 GPa by in situ high-pressure Raman experiments and first-principles calculations at 300 K. As validated by the experiments and calculations, the distortion of layered oxide-TiO 6 in Li 2 TiO 3 is crucial in the phase transition. By modulating the gap between octahedral-TiO 6 layers, we propose a potential Li 2 TiO 3 structural model for improving the electrochemical performance of lithium-ion batteries. Our findings suggest that, based on its high-pressure phase, Li 2 TiO 3 is a promising candidate for layered cathode materials and solid tritium breeding materials for lithium-ion batteries. We propose a potential Li 2 TiO 3 structural model for improving the electrochemical performance of lithium-ion batteries systems by modulating the electrode material crystal structure, for instance, the gap between octahedral-TiO 6 layers.