Cu/Li4Ti5O12 scaffolds as superior anodes for lithium-ion batteries

Abstract

Nanostructured active materials with both high-capacity and high-rate capability have attracted considerable attention, but they remain a great challenge to be realized. Herein, we report a new route to fabricate a bicontinuous Cu/Li4Ti5O12 scaffold that consists of Li4Ti5O12 nanoparticles (LTO NPs) with highly exposed (111) facets and nanoporous Cu scaffolds, which enable simultaneous high-capacity and high-rate lithium storage. It is a 'one stone, two birds' strategy. When tested as the anode in lithium-ion batteries LIBs, Cu/LTO showed superior performance, such as a lifespan greater than 2000 cycles and an ultrafast charging time (<45 s). Notably, the ultrahigh capacity slightly larger than the theoretical value was also observed in Cu/LTO at low current density. Density functional theory calculations and detailed characterizations revealed that the highly exposed (111) facets on the edge are the reason for its unique storage mechanism (8a+16c), which is different from the transition between 8a and 16c in bulk LTO.