A long-life lithium-ion battery with a highly porous TiNb2O7 anode for large-scale electrical energy storage

Abstract

Lithium-ion batteries (LIBs) represent the most important and advanced technology among secondary batteries. After decades of efforts, graphite is still the dominant anode material in commercial LIBs; however, there would be some challenging for the use of graphite based batteries in the power-grid application because of their limited cycle life and safety concerns. Here, we report a facile approach to prepare nanoporous TiNb2O7 anodes exhibiting a much higher storage capacity (281 mAh g-1) than that of the well-known Li4Ti5O12 (~160 mAh g-1) with similar average storage voltage. The interconnected nanoporous framework composed of nanocrystals leads to drastically enhanced rate (a capacity retention of 70% at 20C) and cycling performance (a very small capacity decay of 0.016% per cycle over 1000 cycles) with high coulombic efficiency (around 100%). The present report demonstrates a significant progress for the development of TiNb2O7 based long-life stationary lithium-ion batteries with high energy density.