Double diamond structured bicontinuous mesoporous titania templated by a block copolymer for anode material of lithium-ion battery

Titania has received considerable attention as a promising anode material of Li-ion battery (LIB). Controlling the structure and morphology of titania nanostructures is crucial to govern their performance. Herein, we report a mesoporous titania scaffold with a bicontinuous shifted double diamond (SDD) structure for anode material of LIB. The titania scaffold was synthesized by the cooperative self-assembly of a block copolymer poly(ethylene oxide)-block-polystyrene template and titanium diisopropoxide bis(acetylacetonate) as the inorganic precursor in a mixture solvent of tetrahydrofuran and HCl/water. The structure shows tetragonal symmetry (space group I4₁/amd) comprising two sets of diamond networks adjoining each other with the unit cell parameter of a = 90 nm and c = 127 nm, which affords the porous titania a specific surface area (SSA) of 42 m²·g⁻¹ with a mean pore diameter of 38 nm. Serving as an anode material of LIB, the bicontinuous titania scaffold exhibits a high specific capacity of 254 mAh·g⁻¹ at the current density of 1 A·g⁻¹ and an alluring self-improving feature upon charge/discharge over 1,000 cycles. This study overcomes the difficulty in building up ordered bicontinuous functional materials and demonstrates their potential in energy storage application.