Bagasse-Derived Hard Carbon Anode with an Adsorption–Intercalation Mechanism for High-Rate Potassium Storage

Hard carbon is a kind of abundant-resource and cost-effective anode material for potassium-ion batteries to realize commercialization shortly. However, the poor rate performance and ambiguous energy storage mechanism of hard carbon remain great bottlenecks. In this study, bagasse-pyrolyzed hard carbon (BC) is prepared by the pyrolysis of bagasse, which exhibits a larger surface area and better electrical conductivity than sugarcane-pyrolyzed hard carbon (SC). The BC exhibits a high reversible capacity of 235 mAh g–1 at 100 mA g–1 and a high rate (161 mAh g–1 at 1000 mA g–1) for K+ storage, which are better than those of SC (108 mAh g–1 and 49 mAh g–1). In situ X-ray diffraction and Raman results reveal the "adsorption–intercalation" K+ storage mechanism and prove that the favorable defects endow BC with better electrochemical capability.