ACS APPLIED MATERIALS & INTERFACES, vol.12, no.21, pp.23860-23866, 2020 (SCI-Expanded)
High-entropy oxides (HEOs), which are a new class of single-phase solid solution materials, have recently attracted significant attention as an anode material for lithium-ion batteries (LIBs). In this study, (MgCoNiZn)(1-x)LixO (x = 0.05, 0.15, 0.25, and 0.35) HEOs were synthesized and their electrochemical performances as the anode material were observed in LIBs. X-ray photoelectron spectroscopy (XPS) analysis showed that the increase in the lithium cation concentration causes generation of more oxygen vacancies, which greatly affected the electrochemical performance of (MgCoNiZn)(1-x)LixO HEO anodes, in the structure. The more the oxygen vacancy concentration in the anode, the higher the discharge capacity in the LIB. The (MgCoNiZn)(0.65)Li0.35O anode had 1930 mA h g(-1) initial and 610 mA h g(-1) stable (after 130 cycles) discharge capacities at a current density of 1000 mA g(-1). This work clearly indicated that designing a HEO with abundant oxygen vacancies in the structure was a very efficient strategy to improve the electrochemical performance of the HEO electrode for LIBs.