A Lithium-Rich Compound Li7Mn(BO3)3 Containing Mn~(2+) in Tetrahedral Coordination: A Cathode Candidate for Lithium-Ion Batteries

摘要

Four-coordinate Mn~(2+) is a rare species owing to the lower ligand-field stabilization compared to the octahedral environment and—to our knowledge—was hitherto only reported with structure-directing multidentate ligands. Li~+ ions tend to be octahedrally coordinated but may also appear in a tetrahedral environment, for example, in Li2O. The title compound Li7Mn(BO3)3 contains a relatively large fraction of cations where both Li~+ and Mn~(2+) are in tetrahedral coordination environments with the exception of two Li sites. It can be written as M~I7M~(II)1(M~(III)3)O9 with M:O = 11:9 (where M = Li, Mn, B).