Novel Sepiolite‐Based Materials for Lithium‐ and Sodium‐Ion Storage

Natural sepiolite is widely used as an inorganic template to prepare functional nanomaterials. Herein, raw sepiolite and ultrafine TiO 2 nanocrystals–decorated sepiolite nanofibers are fabricated by a hydrothermal reaction followed by an annealing process. For Li‐storage, the TiO 2 /sepiolite composites exhibit higher specific capacity and a longer lifespan than raw sepiolite. At a current density of 0.3 A g −1 , the optimized TiO 2 /sepiolite composites deliver a discharge capacity of 1811 and 618 mAh g −1 at 1st and 300th cycle, respectively. In addition, the composites show a very stable specific capacity of 100 mAh g −1 at a current density of 0.1 A g −1 for Na‐storage up to 100 cycles.