Hierarchically Pomegranate-Like MnO@porous Carbon Microspheres as an Enhanced-Capacity Anode for Lithium-Ion Batteries

Transition-metal oxides have attracted much attention as promising anode materials, owing to high theoretical specific capacity for lithium-ion batteries (LIBs). However, rapid performance degradation derived from poor electrical conductivity and drastic volume changes during the repeated lithium insertion/extraction processes has limited their practical applications. In this work, we design and prepare pomegranate-like microspheres of nano-sized MnO particles with gaps among them as the core and porous carbon as the shell (designated as PCMS@MnO) by using a facile three-step process. In such unique PCMS@MnO, the porous carbon shell from phenolic resin is beneficial for the electronic conductivity and wettability, whereas the nano-sized MnO particles with gaps among them confined in the porous carbon shell can effectively prevent aggregation and pulverization of active materials. As an anode material for LIBs, the PCMS@MnO with a carbon content of about 12 wt % exhibits remarkably high reversible capability (935 mAh g⁻¹ at 100 mA g⁻¹), outstanding rate performance, and superior cycling stability (527 mAh g⁻¹ of 2000 mA g⁻¹ after 2000 cycles). Our results suggest a great potential of pomegranate-like transition-metal oxide-based composites as anode materials in high-performance LIBs.