Sponge-like NiCo2O4/MnO2 ultrathin nanoflakes for supercapacitor with high-rate performance and ultra-long cycle life

Abstract

We present a simple strategy for synthesizing sponge-like NiCo₂O₄/MnO₂ ultrathin nanoflakes, which exhibit a high specific capacitance of 935 F g⁻¹ at 1 A g⁻¹, excellent rate performance (74.9% retention at 50 A g⁻¹), and ultra-long cycling stability (103.1% of the initial capacitance after 25 000 cycles).