Commodity Elastomer-Derived Ordered Mesoporous Hard Carbon for High-Performance Sodium-Ion Battery Anodes

Abstract

The growing prominence of hard carbon as a promising anode material for sodium-ion batteries has sparked significant research interest in recent years. In this work, we demonstrate the synthesis of ordered mesoporous hard carbons (OMHCs) with pore sizes of approximately 11 nm via direct pyrolysis of crosslinked polystyrene-block-polybutadiene-block-polystyrene (SBS) triblock copolymers. The SBS-derived OMHC features large carbon interlayer spacings and tunable mesopore populations, engineered to enhance sodium-ion storage. Particularly, the optimal OMHC exhibits a reversible capacity up to 391 mAh/g at a current density of 50 mA/g with initial Coulombic efficiencies of 77.4%, along with excellent rate capability and cycle stability in the Na|OMHC cell. Furthermore, the OMHC electrode can operate under very high current density up to 2 A/g while still showing excellent reversible capacity over a thousand cycles. This work advances the synthesis and application of OMHCs for sodium-ion batteries using low-cost precursors and scalable processes.