High-Capacity Oxide Cathode beyond 300 mAh/g

Abstract

The pursuit of high-energy-density lithium-ion batteries (LIBs) hinges upon the relentless development of advanced cathode materials. The inherent high operating voltage renders oxide cathodes the most favored option for this objective. Even with the exceptional capacity of ∼300 mAh/g exhibited by lithium-rich manganese oxide cathodes, the cell-level energy density at present remains constrained at 400 Wh/kg. Consequently, a transformative breakthrough is urgently needed to revolutionize oxide cathode materials with ultrahigh capacity (>300 mAh/g) and thereby enable the design of LIBs for a broad range of applications. In this Focus Review, the electrochemical performances of various oxide cathodes are comprehensively scrutinized, with particular emphasis on those characterized by a Li/O ratio greater than 0.6 (Li1+xTM1–xO2, x > 0.2, where TM denotes transition metal). We emphasize that the construction of multidimensional defects offers a promising means of resolving the present quandary regarding the trade-off between structural stability and capacity for high-capacity oxide cathodes.