A fast composite-hydroxide-mediated approach for synthesis of 2D-LiCoO2 for high performance asymmetric supercapacitor

Two-dimensional (2D) materials have been attracting research interest due to their specific properties including supper large surface area, more active sites and fast electron transmission, which are beneficial to the improvement of energy and power densities for supercapacitors (SCs). In this paper, 2D LiCoO 2 (2D-LCO) is prepared by fine-tuning the time in the synthesis process through a fast-composite-hydroxide-mediated approach. The electrode with the 2D-LCO mass load of 0.75 mg/cm 2 exhibits the high specific capacitance of 310 mF/cm 2 at 5 mV/s. Moreover, the asymmetric supercapacitor assembled by 2D-LCO//Fe 2 O 3 /FeOOH delivers a high areal energy density of 56.25 μWh/cm 2 at 1100 μW/cm 2 with working window of 2.2 V and an excellent cycling stability of 80% at current density of 10 mA/cm 2 for 2000 cycles.