High-performance lithium storage in Li2SnO3-graphite composite enabled by Ag3Sn nanoparticles and oxygen vacancies

Abstract

With high capacity (653 mAh g−1) and low voltage (0.6 V), Li2SnO3 is considered as a prospective anode material for Li-ion batteries (LIBs). Nevertheless, its practical uses are restricted by inferior electrochemical kinetics and fast capacity decay. Herein, a novel ternary composite of Ag3Sn alloy-lithium stannate-graphite (denoted as Ag3Sn-Li2SnO3-x-G) is designed and fabricated by ball milling and vacuum annealing. In this ternary composite, oxygen vacancy-containing Li2SnO3 and Ag3Sn alloy nanoparticles are homogeneously dispersed in the exfoliated graphite nanosheets. The introduction of Ag3Sn nanoparticles and oxygen vacancies into Li2SnO3-graphite can significantly enhance charge transport kinetics and structure stability of composite during the lithiation and delithiation processes. Benefiting from these merits, the Ag3Sn-Li2SnO3-x-G composite presents excellent cycling stability (782.4 mAh g−1 at 0.2 A g−1 after 200 cycles) and impressive rate capability (251.5 mAh g−1 at 2 A g−1). Broadly, this design strategy can provide an effective and reliable route for constructing advanced metal oxide-based anode materials for high-energy LIBs.