Eco-saving and green anode materials for Li-ion batteries utilizing oxide-decorated biocarbon substrates proceeded from cassava residues

In this work, an eco-saving and green anode structure (CRC) of MnO/Mn3O4 nanoparticles (NPs) anchored on biocarbon substrates derived from cassava residues (CRs) was designed and fabricated successfully by an in-situ method from MnCl2 and CRs. The amount of MnO/Mn3O4 NPs in the CRC can be effectively modulated by altering the mass ratio of MnCl2 to CRs. In Li-ion batteries, CRC anodes exhibit outstanding electrochemical performances such as high Coulombic efficiency, high capacity, excellent rate capacity, and stable cycling. The high reversible capacity of 698 mAh g−1 at 100 mA g−1 can be achieved even after 100 cycles. This could be accredited to the special structure of MnO/Mn3O4 NPs and biocarbon substrates. First, CR-derived biocarbon favors the alleviation of volume change and prevents the aggregation of MnO/Mn3O4 NPs during cycling. Then, an appropriate amount of MnO/Mn3O4 NPs formed on the surface and empty cages of biocarbon generate various free contacting channels between the electrolyte and active materials. Finally, MnO/Mn3O4 NPs intensify the electrochemical activity of biocarbon, leading to an increase in Li-storage capacities. Therefore, the facile in-situ method in this work is quite promising to produce cost-effective and eco-friendly anodes for Li-ion batteries utilizing recycled CRs and simple chemicals.