Synthesis of Hard Carbon-TiN/TiC Composites by Reacting Cellulose with TiCl4 Followed by Carbothermal Nitridation/Reduction.

Titanium tetrachloride is reacted with hydroxide groups on cellulose (cotton wool) before firing to convert the cellulose to hard carbon. Hard carbon-nanocrystalline titanium nitride composites with a good distribution of the titanium across the fibrous hard carbon structure were obtained by firing the treated cellulose under nitrogen. Hard carbon-nanocrystalline titanium carbide composites were obtained by firing under argon. The composites were tested as anode materials for sodium ion batteries, and the HC-TiN composite delivers a better capacity retention than that of hard carbon over 50 cycles. The synthesis method demonstrated here provides an effective route to composites of metal nitrides and carbides with carbon that may be of interest for other energy technologies as well as for sodium batteries.