Carbon Nanosheet Anode for Sodium‐Ion Storage and Its Application in Sodium‐Ion Hybrid Capacitors

Abstract In this study, sodium ion hybrid capacitors (SIHCs) constructed by using battery‐type carbon nanosheet (CNS) as anode and capacitive activated carbon (AC) as cathode are reported. The CNSs with large interlayer spacing were deposited on Na 2 CO 3 powder by using chemical vapor deposition method. The CNS anode for sodium ion storage exhibits outstanding rate capability (138 mAh g −1 at 10 A g −1 , 63 % retention of the capacity at 0.05 A g −1 ) and excellent long‐term cyclability at 10 A g −1 after 12500 cycles. Benifting from high performance of anodes abovemensioned, the assembled SIHC based on CNS and AC, operated in a voltage window of 1.0∼4.0 V, delivers a high specific energy of 135 Wh kg −1 at 250 W kg −1 and a maximum power of 25 kW kg −1 with the output 69 Wh kg −1 .