Facile synthesis of rutile TiO2 mesocrystals with enhanced sodium storage properties

Abstract

With the aim of developing high performance anode (negative) materials for sodium ion batteries (NIBs), rutile TiO₂ with mesocrystalline structure were designed and used for enhancing the discharge capacity and reaction kinetics. The nanoporous rutile TiO₂ mesocrystals constructed by crystallographically oriented nanoparticle subunits with tunable microstructures were successfully prepared via a facile synthesis route. Such rutile TiO₂ architecture possesses a large surface area (157 m² g⁻¹), nanoporous nature and single-crystal-like structure, which could provide a high level of accessibility for the electrolyte and more active sites, and allow the fast electron and ion transport compared with the irregularly oriented nanoparticles. When evaluated as an anode material for sodium-ion storage, this unique architecture exhibited a high reversible capacity over 350 mA h g⁻¹ at 50 mA g⁻¹, superior rate capability with a stable capacity of 151 mA h g⁻¹ at 2 A g⁻¹ and good cycling stability.