Carbon–Manganese Oxide Composite Derived from Wheat Flour: Kitchen-Inspired Green Synthesis and Applications in Energy Storage

The quest for better alternatives for graphite anodes is the holy grail in the field of energy storage technologies. Biomass-derived carbon has been widely explored as the energy-dense and cost-effective option but involves several pre/post-conditioning steps. In this study, kitchen chemistry concepts of fermentation have been utilized to obtain sustainable carbon anodes from readily available and cost-effective wheat flour and baker’s yeast. The yeast-fermented mixture of wheat flour and MnCO₃ is pyrolyzed under 500 °C to yield porous C-MnO composites, which have been explored as an anode for Li-ion batteries. The material showed superior electrochemical performance with an initial discharge of 1160 mAh g^–1 at 0.15 A g^–1 (after solid electrolyte interface formation). A reversible capacity of 1499 mAh g^–1 was obtained with a concomitant improvement of 30% after 160 cycles exhibiting a “negative fading effect”. Excellent electrochemical behavior has been attributed to the synergistic effect of in situ synthesized, well-dispersed MnO in carbon, the presence of redox-active Mn, and well-connected porosity in nanohybrids. At a high current density of 1 A g^–1, the anode displayed an exemplary initial discharge capacity of 770 mAh g^–1 with a high initial Coulombic efficiency of 90%, which was maintained at 856 mAh g^–1 after 760 cycles. Easy synthesis and excellent electrochemical performance render this material highly promising for battery applications.