Zinc−Ion−Assisted Catalytic Synthesis of Hard Carbon with Superior Plateau Capacity and ICE for Sodium−Ion Batteries

ABSTRACT Hard carbon is regarded as a highly attractive candidate for the anode in sodium−ion batteries (SIBs). Nevertheless, its practical commercial application is severely limited by unsatisfactory low−voltage plateau capacity (<0.1 V), low initial Coulombic efficiency (ICE), and slow electrochemical kinetics in the plateau region. Herein, we propose a simple and cost−effective one−step zinc−ion catalytic pyrolysis strategy to optimize cellulose hard carbon, which exhibits a combination of ultrahigh initial capacity of 480.8 mA h g −1 , a high ICE of 89.8%, and a plateau capacity of 326.5 mA h g −1 . During carbonization, the Zn 2+ ions act simultaneously as a graphitization catalyst and a pore−forming…