A ternary oxygen-vacancy abundant ZnMn2O4/MnCO3/nitrogen-doped reduced graphene oxide hybrid towards superior-performance lithium storage

Abstract

Transition metal oxides (TMOs) and metal carbonates exhibit high specific capacity, abundant reserves on Earth, and environmental friendliness as anode materials for lithium-ion batteries (LIBs). However, their poor electrical conductivity and serious volume expansion lead to rapid capacity decay. Herein, a stable and highly conductive composite of an oxygen-vacancy abundant nitrogen-doped reduced graphene oxide (NG) encapsulated ZnMn₂O₄/MnCO₃ (ZnMn₂O₄/MnCO₃/NG) hybrid is successfully fabricated, which can provide more spaces for rapid ion diffusion and corroborate fast electron transport. The ZnMn₂O₄/MnCO₃/NG hybrid exhibits an incredible reversible capacity (916 mA h g⁻¹ at 0.1 A g⁻¹), preeminent cycling stability (800 mA h g⁻¹ at 1 A g⁻¹ after 300 cycles) and outstanding rate capability (459 mA h g⁻¹ at 2 A g⁻¹). The excellent lithium storage performance of ZnMn₂O₄/MnCO₃/NG is attributed to the synergistic effect between ZnMn₂O₄ and MnCO₃, the addition of nitrogen and oxygen defects, and the stable structures of NG, which relieve the volume expansion of the electrode material, improve the electronic conductivity and enhance structural stability and surface capacitive response. This work provides a new idea for constructing oxygen-vacancy abundant NG encapsulated bimetal oxides for energy storage of LIBs.