Fabrication and synergistic control of ternary TiO₂/MoO₂@NC hollow spheres for high-performance lithium/sodium-ion batteries anodes

Constructing nanostructured hollow materials is one of the most effective approaches to improve the cycling stability in batteries by accommodating the volume variation. Combined with the synergy of hybrid composition, high-performance energy storage materials are expected to be achieved. Herein, the anatase TiO₂ is coated into a MoO₂@N-doped carbon hollow sphere structure (denoted as TiO₂/MoO₂@NC HS) through a simple two-step method. The unique TiO₂/MoO₂@NC HS composite overcomes the poor cyclic stability of MoO₂ and the low specific capacity of TiO₂. Moreover, its hollow sphere structure facilitates electrolyte access and simultaneously provides shorter charge transportation paths, which assures rapid Li⁺/Na⁺ reaction kinetics. When utilized as an anode in LIBs /SIBs, TiO₂/MoO₂@NC HS composite exhibits a satisfactory electrochemical performance with high reversible capacities of 1423.9 mAh g⁻¹ at 100 mA g⁻¹ after 200 cycles in LIBs and reaches 572.7 mAh g⁻¹ after 1000 cycles at 200 mAg⁻¹ in SIBs. Furthermore, the full cell TiO₂/MoO₂@NC HS anode coupled with NCM₁₁₁ cathode shows decent capacity with long cycling stability. This study offers a novel strategy to obtain anode composite that will find applications in energy storage devices.