Superb Li-Ion Storage of Sn-Based Anode Assisted by Conductive Hybrid Buffering Matrix.

Although Sn has been intensively studied as one of the most promising anode materials to replace commercialized graphite, its cycling and rate performances are still unsatisfactory owing to the insufficient control of its large volume change during cycling and poor electrochemical kinetics. Herein, we propose a Sn-TiO-C ternary composite as a promising anode material to overcome these limitations. The hybrid TiO-C matrix synthesized via two-step high-energy ball milling effectively regulated the irreversible lithiation/delithiation of the active Sn electrode and facilitated Li-ion diffusion. At the appropriate C concentration, Sn-TiO-C exhibited significantly enhanced cycling performance and rate capability compared with its counterparts (Sn-TiO and Sn-C). Sn-TiO-C delivers good reversible specific capacities (669 mAh g after 100 cycles at 200 mA g and 651 mAh g after 500 cycles at 500 mA g) and rate performance (446 mAh g at 3000 mA g). The superiority of Sn-TiO-C over Sn-TiO and Sn-C was corroborated with electrochemical impedance spectroscopy, which revealed faster Li-ion diffusion kinetics in the presence of the hybrid TiO-C matrix than in the presence of TiO or C alone. Therefore, Sn-TiO-C is a potential anode for next-generation Li-ion batteries.