Core‐shell MnO@MnFe₂O₄ Anchored by Reduced Graphene Oxide as Anode of Li‐Ion Batteries Operated under Ultrawide Temperature Range

A facile high‐temperature solution route to a monodisperse core‐shell structure of MnO (core) and MnFe 2 O 4 (shell) (abbreviated as MFO) nanoparticles anchored on reduced graphene oxide (rGO) has been established. Subsequently, MnO@MnFe 2 O 4 @rGO nanocomposites are utilized as advanced anode materials for high‐performance Li‐ion batteries. MnO@3MFO@rGO containing 22.5 wt% of the rGO composite (with a 1 : 3 molar ratio of MnO/MFO) as the electrodes delivered a remarkable cycling performance, that is, 587.8 mAh g −1 at a current density of 200 mA g −1 after 200 cycles at ambient temperature with an ultralow capacity fading (0.10 % per cycle). More importantly, the electrodes afforded excellent capacity stability under various operation temperatures (ca. −20 to 70 °C), such as an excellent reversible capacity of 1067 mA h g −1 at a current density of 500 mA g −1 after 300 cycles at 60 °C, and remarkable low‐temperature performance of a reversible capacity of 208.7 mA h g −1 at a current density of 200 mA g −1 at −20 °C. Therefore, MnO@3MFO@rGO nanocomposites are considered as promising battery materials that can be operated in harsh environments.