Energy‐Efficient Induction Carbonization: Tailoring Pore Structures in Hard Carbon Anodes Toward Enhanced Electrochemical Performance

ABSTRACT Hard carbon (HC) is currently the predominant anode material for sodium‐ion batteries; however, its practical application is still limited by insufficient initial Coulombic efficiency (ICE) and plateau capacity. Meanwhile, conventional HC production relies on energy‐intensive carbonization processes with considerable carbon emissions. Here, an induction heating carbonization strategy is developed for extruded biocarbon columns derived from biomass‐based biochar and bio‐oil, enabling simultaneous enhancement of electrochemical performance and production sustainability. Bio‐oil combined with high‐pressure extrusion suppresses open pores, whereas induction heating generates localized eddy currents and concentrated Joule heating that accelerate carbon rearrangement and promote closed pore formation. As a result, the closed‐to‐open pore volume ratio increases from 0.32 to 85.18, leading to improved ICE (95.0% vs. 84.4%) and plateau capacity ratio (77.6% vs. 64.7%) relative to conventional carbonized HC. Life‐cycle assessment further indicates an approximately 35% reduction in global warming potential. Overall, this work presents an energy‐efficient, low‐emission route for producing high‐performance HC anodes.