LAUSR

Abstract Oxygen doped activated carbon (OAC) is synthesized through chemical activation and nitric acid oxidation. The OAC/SnO2 composite is prepared by a novel vacuum melting method. With this approach, SnO2 nanoparticles are effectively doped into the nanoporous of OAC and enhance the bonding properties between OAC and SnO2, which will avoid the aggregation and growth of SnO2 nanoparticles during the long charge-discharge process. After 800 cycles at 500 mA g−1 as electrode materials for half cells, the OAC/SnO2 exhibits a higher reversible capacity (927 mAh g−1). Under the condition of 787 W kg−1, the hybrid-type lithium ion capacitor assembled using the OAC/SnO2 and nitrogen doped activated carbon electrode delivers a high energy density of 151 Wh kg−1. The hybrid device also shows high cycle performance (93% capacity retention after 9000 cycles) at 2.0–4.5 V.