In-situ synthesis of Ta2O5@few-layered rGO core-shell nanosphere with abundant oxygen vacancies for highly stable lithium-ion battery

Abstract

Metal oxide is a promising anode material in LIBs, which can be further improved by covering with few-layered graphene oxide (FL-rGO). Furthermore, the formation of oxygen vacancies can greatly improve the electrochemical performance; however, the concentration regulation of oxygen defects remains a challenge. In this work, a facile in situ calcination was explored to synthesize Ta2O5@FL-rGO core-shell nanospheres with abundant oxygen vacancies between Ta2O5 and few-layered graphene oxide. And the as-prepared Ta2O5@FL-rGO exhibited highly electrochemical performance, including superior conductivity, high reversible capacity (442.3 mA h g−1 at 0.1 A g−1 after 100 cycles), good cycling performance (288.7 mA h g−1 at 5 A g−1 over 600 cycles), and excellent rate capability, compared with that of bare Ta2O5 and other Ta2O5 based electrode in the literature.