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 2 @C nanocomposites through the direct mineralization of seaweed‐derived alginic acid cryogel by TiCl 4 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 2 precursor, TiCl 4 . The resulting TiO 2 @alginic acid composite was transformed either into pure mesoporous TiO 2 by calcination or into mesoporous TiO 2 @C nanocomposites by pyrolysis. By comparing with a nonporous TiO 2 @C composite, the importance of the mesopores on the performance of electrodes for lithium‐ion batteries based on mesoporous TiO 2 @C composite was clearly evidenced. In addition, the carbon matrix in the mesoporous TiO 2 @C nanocomposite also showed electrochemical activity versus lithium ions, providing twice the capacity of pure mesoporous TiO 2 or alginic acid‐derived mesoporous carbon (A600). Given the simplicity and environmental friendliness of the process, the mesoporous TiO 2 @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.