Mechanically and structurally stable Sb2Se3/carbon nanocomposite as anode for the lithium-ion batteries.

Metal chalcogenides undergoing alloying and conversion mechanism can give high capacity as anode for lithium-ion batteries. However, large volume change and phase segregation lead to poor cycle performance. In this study, we focus on Sb 2 Se 3 and develop methods to enhance its long-term stability and reversibility. In particular, we find that carbon encapsulation reduces volume change during lithiation/delithiation and facilitates the recombination process of Sb and Se even after long cycling. With an addition of 20 wt% acetylene black, the Sb 2 Se 3 /C nanocomposite material exhibits an excellent cycle performance with a charge capacity of 545 mAh g−1 at 250 mA g−1 after 1000 cycles, corresponding to a capacity retention of 99.3%. We also demonstrate a full cell with LiFePO 4 cathode and Sb 2 Se 3 /C anode that is capable of delivering a stable capacity of 340 mAh g−1 at 1 A g−1 (about 3 C rate) after 300 cycles. • Sb 2 Se 3 nanoparticles encapsulated with carbon matrix is synthesized via mechanical ball-milling. • Carbon matrix enhances the mechanical stability of the electrode and suppresses phase segregation. • Sb 2 Se 3 @20%AB delivers a stable capacity of 545 mAh g−1 over 1000 cycles. • Sb 2 Se 3 @20%AB/LiFeO 4 full cell shows good rate capability and cycle stability. [ABSTRACT FROM AUTHOR]