Ni-Co PBA-decorated CNTs as battery-type cathode materials for potassium-ion hybrid capacitors
B. Purusottam Reddy, Jayanth Babu Karnam, Chandra Sekhar M, Si‐Hyun Park
Abstract
Recently, considerable attention has been given to Prussian blue analogues (PBAs) as efficient battery-type electrode materials for devising advanced hybrid supercapacitors . In this study, nickel hexacyanocobaltate (NiHCC) was considered as a PBA system to successfully synthesize carbon nanotubes- (CNTs) and carbon nanofibers- (CNFs) hybridized NiHCC nanocomposites following a single-step hydrothermal process and the corresponding battery-type electrochemical storage behavior was investigated in 3 M KOH. All the synthesized electrodes exhibited battery-type charge storage mechanisms with excellent stability. The NiHCC-CNT composite (NiHCC@CNT) electrode, in particular, exhibited excellent charge storage capacity (348 mAh g −1 at 1 Ag −1 ) owing to its high electrochemically active surface area , low charge transfer resistance, and efficient utilization of redox centers for K + ion storage. Moreover, the hybrid capacitor constructed using NiHCC@CNT exhibited excellent cycling stability over 5000 cycles with a maximum energy density of 59 W h Kg −1 at a power density of 1798 W Kg −1 . This work demonstrates the potential of NiHCC@CNT composite as a cathode material for K + ion supercapacitors .