TiC-coated titanium foam via CVD as a 3D framework sulfur host for high-performance lithium–sulfur batteries

Lithium–sulfur (Li–S) batteries are promising candidates for next-generation energy storage devices due to their high energy density, low cost, and environmental friendliness. However, their practical application remains limited by the polysulfide shuttle effect, sulfur volume expansion, and poor electronic conductivity of S and Li₂S. In this study, titanium carbide (TiC) was grown on Ti foam using chemical vapor deposition (CVD) to construct a binder-free, highly conductive, and porous TiC-Ti three-dimensional (3D) framework sulfur host for enhancing the Li–S battery performance. This 3D framework combines highly porous Ti foam with the polar surface of CVD-synthesized TiC nanoflowers, enabling efficient electron and ion transport, anchoring polysulfides to mitigate the shuttle effect, and accommodating sulfur volume expansion for enhanced cycling stability. Our study demonstrated that Li–S batteries utilizing TiC-Ti 3D framework@S cathodes achieved a high initial discharge capacity of 1506 mAh·g⁻¹ at 0.1 C and maintained 93.3% of their capacity after 500 cycles at 1 C, with an exceptionally low average capacity decay of 0.01% per cycle. Additionally, the TiC-Ti 3D framework@S cathodes exhibited reduced charge transfer resistance after cycling, indicating enhanced interfacial reaction kinetics and stability. These findings confirm that the CVD-synthesized TiC-Ti 3D framework can serve as an efficient binder-free sulfur host, which provides a promising material and structural strategy for high-performance Li–S battery design.