Anion charge dependent lithium ion diffusion in solids

Our recent studies of the chalcopyrite-structured sulfides and non-spinel-structured halides show that the lithium-ion migration energy barrier can be effectively reduced by comprehensively regulating the anion charge and lithium-ion coordination environments. For example, for lithium ion diffusion between two adjacent lithium-anion octahedrons through a tetrahedral transition state, the greater the anionic charge is, the lower the lithium ion diffusion energy barrier will be. While for lithium ion diffusion between two adjacent lithium-anion tetrahedrons through an octahedral transition state, the smaller the anion charge is, the lower the lithium ion diffusion barrier will be. This new understanding of comprehensively regulating the anion charge and lithium-ion coordination environments to enhance lithium ion transport can be applied for the design and optimization of new superionic conductors.