Sb4O5Cl2 Embedded in Carbon Polyhedra For Fast Charge Kinetics Towards High-Capacity Lithium-ion Capacitors

SbOx with high theoretical capacity are regarded as ideal negative electrode materials for lithium-ion capacitors (LICs). However, its poor conductivity and vast volume change during lithiation/de-lithiation process limit electrochemical performance and practical application. Herein, we present an atomic-scale structural engineering strategy to confine Sb4O5Cl2 nanoclusters in zeolitic imidazolate framework (ZIF)-derived carbon polyhedra (ZCP) as a pomegranate-like polyhedra composite anode. The incorporation of Sb4O5Cl2 and carbon polyhedral regulate the Femi level and coordination environment of Sb atoms for enhanced electronic conductivity and accelerated ion-transfer kinetics. Moreover, the obtained pomegranate-like structure can accommodate the volume expansion of Sb4O5Cl2 during cycling. As a result, the Sb4O5Cl2@ZCP electrode exhibits a high capacity of about 800 mAh g-1 and excellent cyclic stability. The LICs based on the Sb4O5Cl2@ZCP anode and active carbon cathode possesses a high energy density of 122 Wh kg-1 and a power density of 9.7 kW kg-1. Simultaneously, a halogen ion substitution chemistry is also disclosed for high-performance doped SbOx. This study provides effective guidelines for the design of large-capacity and high-rate anode in LICs