Tailored Design Ti4+ Coordination via Coplanar Carboxyl and Hydroxyl Groups Toward High Purity TiO2(B) with Ultrafast Li+ Storage

Abstract

AbstractTiO2(B) is a promising anode material for lithium‐ion batteries (LIBs) due to its fast lithiation/delithiation kinetics, however, its thermodynamic metastable nature makes it difficult to synthesize pure phase, which significantly affects its lithium storage capability. Herein, the structural evolution from precursor to TiO2(B) is systematically investigated and it is revealed that the formation of high‐purity monoclinic HTO (hydrogen titanate) precursor is the key to preparing TiO2(B) with high purity, which can be achieved via tailored‐design the solvent structures of Ti4+ in the precursor solution. Glycolic acid (GA) is favorable for the synthesis of high‐purity HTO, benefiting from its simplest spatial structure and coplanar carboxyl and hydroxyl groups for Ti4+ coordination, further leading to the formation of TiO2(B) with a high phase purity of 98.83% that exhibits excellent rate capability (80.5% capacity retention with current densities increased from 1 to 30 C), thus making it a promising candidate for simultaneous energy and power density LIBs anode.