SO42−-ion induced synthesis of 3D porous hydrangea-shaped anatase TiO2 as high performance anode material for lithium/sodium-ion batteries.

TiO₂ materials are considered one of the promising candidates for lithium/sodium-ion batteries (L/SIBs) due to its excellent safety and abundant resources. However, the low ion diffusion coefficient becomes a bottleneck in restrict its development. In this work, three-dimensional (3D) porous hydrangea-shaped anatase TiO₂ (ATO) was synthesized through the synergistic effect of de-alloying and SO₄²⁻ induced chemical synthesis. During the chemical synthesis process, SO₄²⁻ and TiO₆²⁻ octahedra are bound by static electricity, as the spatial effect of SO₄²⁻ can influence the octahedral arrangement in favor of precipitating anatase TiO₂. In the SIBs, ATO as anode material provided an excellent capacity of 190 mAh g⁻¹ after 100 cycles at a current density of 50 mA g⁻¹. Electrochemical kinetic tests show that the pseudocapacitive behavior contributes to 86% of the capacity at a scan rate of 1 mV s⁻¹, mainly due to the high specific surface area provided by its unique microstructure, and also shows excellent electrochemical performance in the LIBs tests. This study provides a novel strategy for the simple and large-scale production of TiO₂ anode materials with high-performance L/SIBs. [ABSTRACT FROM AUTHOR]