Mesoporous Nanohybrids of 2D Ni-Cr-Layered Double Hydroxide Nanosheets Pillared with Polyoxovanadate Anions for High-Performance Hybrid Supercapacitor

In this study, the use of exfoliation-restacking strategy to prepare mesoporous nanohybrids of 2D Nickel-chromium-layered double hydroxide (Ni-Cr-LDH) nanosheets pillared with polyoxovanadate (POV) anions (Ni-Cr-LDH-POV) for a high-performance hybrid supercapacitor (HSC) is demonstrated. The pillaring approach of Ni-Cr-LDH monolayers with POV anions via exfoliation-restacking strategy yields mesoporous ordered layered structure with a high surface area and interconnected network morphology. The pillared hybridization of Ni-Cr-LDH with POV anions boosts the electrochemical performance of the pristine Ni-Cr-LDH, which is attributed to the development of layer-by-layer stacking structure with expanded gallery height and high surface area interconnected network morphology. The Ni-Cr-LDH-POV nanohybrid electrode exhibits an improved specific capacity of 294.5 mAh g(-1) as compared to pristine Ni-Cr-LDH electrode (98.9 mAh g(-1)) at 1 mA cm(-2) with 82% capacity retention after 5000 charge-discharge cycles. A full-cell HSC composed of mesoporous Ni-Cr-LDH-POV nanohybrid as a cathode and reduced graphene oxide (rGO) as an anode delivers a maximum specific energy of 57.78 Wh kg(-1) and specific power of 1.59 kW kg(-1) with 87% cyclic durability over 10 000 charge-discharge cycles. The present study demonstrates the usefulness of the pillared Ni-Cr-LDH-POV nanohybrids via exfoliation-restacking strategy for exploring high-performance HSC.