Agaric-assisted synthesis of core-shell MnO@C microcubes as super-high- volumetric-capacity anode for lithium-ion batteries. (June 2020) - Luo, Jin-Di
Abstract: Biomass materials show great potential in replacing mineral carbon source to fabricate novel high-energy electrode materials. However, it is greatly challenging to prepare core-shell carbon hybrid materials with homogeneous dispersion and high tap density features from biomass since biomass-carbons often exhibit blocky structure. Herein, we facilely fabricate the core-shell microcubes of MnO@C (CCM, average size of ∼5 μm) composite with high tap density of 2.17 g cm −3 using natural agaric as raw materials through simple hydrothermal treatments and calcination process. And the formation mechanism of core-shell microcube structures is analysized by the phase separator theory. It is found that the high-tap-density CCM composite with the stable porous carbon shell (∼1 μm) greatly contributes to accommodate the volume change of MnO active material during lithiation/delithiation process and enable rapid electron/ion transport. As expected, the CCM electrode offers a superhigh volumetric capacity of 1628.7 mAh cm −3, the high reversible capacity (1147 mAh g −1 at 0.1 A g −1 ), outstanding rate performance (552 mAh g −1 at 2 A g −1 ) and cycling stability (802 mAh g −1 after 950 cycles at 1 A g −1 ). We believe that the facile and low-cost biomass-intervened strategy is feasible to fabricate practical core-shell structured metal oxide@carbon composites for efficient electrochemical energy storage. Graphical abstract: Core-shell MnO@C microcubes obtained from a biomass-intervened strategy are investigated as LIB anode, and shows high specific volumetric capacity, good cycle stability and rate capability. Image 1 Highlights: A simple agaric-intervened strategy for core-shell MnO@C microcubes. The uniform size of ∼5 μm and stable porous carbon shell (∼1 μm). The composite shows high-tap-density (2.17 g cm −3 ). To accommodate the volume change of MnO during lithiation/delithiation. Superhigh specific volumetric capacity of 1628.7 mAh cm −3 at 0.1 A g −1 Excellent cycling stability (802 mAh g −1 after 950 cycles at 1 g −1 ).