TiO2 Nanocrystal‐Framed Li2TiSiO5 Platelets for Low‐Voltage Lithium Battery Anode

Abstract Titanium‐based anode materials are attracting considerable attention for use in high‐performance lithium‐ion batteries, but the compromised energy density caused by high voltage plateaus and unsatisfactory capacities severely retards their practical applications. Herein, a molten‐salt synthesis of Li 2 TiSiO 5 crystalline platelets and a subsequent selective facet modification by in situ growth of TiO 2 nanocrystal frames are facilely achieved. The discharge voltage plateau at around 0.5 V renders the Li 2 TiSiO 5 anode safe compared with graphite and confers a high energy density compared with zero‐strain Li 4 Ti 5 O 12 anode. With the optimized size, structure, and content of modified TiO 2 nanocrystals associated with the exposed (001) plane of Li 2 TiSiO 5 , the Li 2 TiSiO 5 ‐based anodes can deliver a capacity of above 300 mAh g −1 , enhanced rate performance, and a capacity retention of 66% after 10 000 cycles. In situ X‐ray diffraction and ex situ transmission electron microscopy have demonstrated the structural stability of the anodes upon charge/discharge. Further theoretical calculation reveals 3D migration paths of Li + ions in Li 2 TiSiO 5 . The selective modification of in situ grown TiO 2 nanocrystals on certain facets of crystallites opens a new door for the development of electrode materials possessing superior electrochemical properties.