Pham, H.D.Chodankar, N.R.Jadhav, S.D.Jayaramulu, K.Nanjundan, A.K.Dubal, D.P.2022-08-252022-08-252021Energy Storage Materials, 2021; 34:475-4822405-82972405-8297https://hdl.handle.net/2440/136194Available online 16 October 2020Potassium-ion battery (KIB) is a promising technology for large-scale energy storage applications due to their low cost, theoretically high energy density and abundant resources. However, the development of KIBs is hin- dered by the sluggish K + transport kinetics and the structural instability of the electrode materials during K + intercalation/de-intercalation. In the present investigation, we have designed a potassium-ion capacitor (KIC) using layered potassium niobate (K 4 Nb 6 O 17 , KNO) nanosheet arrays as anode and orange-peel derived activated carbons (OPAC) as fast capacitive cathode materials. The systematic electrochemical analysis with the ex-situ characterizations demonstrates that KNO-anode exhibits highly stable layered structure with excellent reversibil- ity during K + insertion/de-insertion. After optimization, the fabricated KNO//OPAC delivers both a high energy density of 116 Wh/kg and high power density of 10,808 W/kg, which is significantly higher than other similar hybrid devices. The cell also displays long term cycling stability over 5000 cycles, with 87 % of capacity reten- tion. This study highlights the utilization of layered nanosheet arrays of niobates to achieve superior K ‐storage for KICs, paving the way towards the development of high ‐performance anodes for post lithium ‐ion batteries.en© 2020 Elsevier B.V. All rights reserved.Potassium Niobate; Potassium ion capacitor; Waste derived carbon; Energy densityJournal article10.1016/j.ensm.2020.10.0132022-08-25555621Dubal, D.P. [0000-0002-2337-676X]