Anchoring nitrogen-doped carbon particles on lithium titanate to enhance its lithium storage performance

Abstract

Lithium titanate is a promising anode material for lithium-ion batteries, but its specific capacity and rate performance are low, which restricts its further development. In this paper, by modifying with anchoring carbon particles on the surface, the electrochemical energy storage performance of lithium titanate has been improved at a deeper voltage (0.01–3 V vs. Li+/ Li). The experimental results show that the modified lithium titanate has significant improvement in specific capacity, rate and cycle stability (305.7 mAh g−1 at 0.1 A g−1, 157 mAh g−1 at 5 A g−1, and 245.3 mAh g−1 at 0.1 A g−1 after 800 cycles). Further research found that the improvement of lithium titanate performance is mainly related to a multi-step restore of Ti4+ below 0.6 V, but not to the electrochemical redox of Ti4+/Ti3+ at 1.55 V. This work provided an effective way to promote the comprehensive electrochemical performance of LTO-based materials.