Biogel‐Derived Polycrystalline MnO Spheres/S‐Doped Carbon Composites with Enhanced Performance as Anode Materials for Lithium‐Ion Batteries

To meet the practical requirement of advanced storage equipment, electrode materials with low cost, high performance, and readily available large‐scale production are of intensive concern. In this work, a natural marine biomass, gelidium amansii, was used to fabricate novel polycrystalline MnO spheres/S‐doped carbon composites (MnO/SC) with hierarchical porosity by using a simple bio‐sol‐gel and pyrolysis process. By inducing biogels, the unique composites of polycrystalline MnO spheres encapsulated and interwoven in a sulfur‐doped carbon net were created, which leads to a higher loading of active materials in contrast to other reported bio‐derived MnO/C materials. As anode materials for lithium‐ion batteries, the obtained MnO/SC composites delivered a high reversible capacity of 1100 mAh g−1 after 200 cycles at 0.2 A g−1 and a superior long‐term cycling performance of over 500 mAh g−1 after 1000 cycles even at the high current density of 2 A g−1. Therefore, the present work represents a feasible large‐scale fabrication approach toward high‐performance electrode materials on the basis of rich natural biogels. Fabrication through nature: A novel polycrystalline MnO sphere/S‐doped carbon composite with hierarchical porosity is constructed by using a cost‐effective synthetic approach with natural marine biomass, gelidium amansii, as renewable precursors. The composite shows potential as an outstanding anode material for lithium‐ion batteries.