Dehydration of Alginic Acid Cryogel by TiCl 4 vapor: Direct Access to Mesoporous TiO 2 @C Nanocomposites and Their Performance in Lithium-Ion Batteries

A new strategy for the synthesis of mesoporous TiO @C nanocomposites through the direct mineralization of seaweed-derived alginic acid cryogel by TiCl through a solid/vapor reaction pathway is presented. In this synthesis, alginic acid cryogel can have multiple roles; i) mesoporous template, ii) carbon source, and iii) oxygen source for the TiO precursor, TiCl . The resulting TiO @alginic acid composite was transformed either into pure mesoporous TiO by calcination or into mesoporous TiO @C nanocomposites by pyrolysis. By comparing with a nonporous TiO @C composite, the importance of the mesopores on the performance of electrodes for lithium-ion batteries based on mesoporous TiO @C composite was clearly evidenced. In addition, the carbon matrix in the mesoporous TiO @C nanocomposite also showed electrochemical activity versus lithium ions, providing twice the capacity of pure mesoporous TiO or alginic acid-derived mesoporous carbon (A600). Given the simplicity and environmental friendliness of the process, the mesoporous TiO @C nanocomposite could satisfy the main prerequisites of green and sustainable chemistry while showing improved electrochemical performance as a negative electrode for lithium-ion batteries.