Novel stalactiform structural CoNi-rGO for supercapacitors with enhanced electrochemical performance

Abstract

NiCo layered double hydroxide (LDH) has always been a well-explored subject because of its non-toxicity, low cost and excellent electrochemical stability owing to its special layered structure and adjustable chemical composition. Here, stalactiform S-CoNi-rGO possesses structural advantages of spines penetrating and supporting the nanosheets and exhibits high specific capacitance (3922 F g⁻¹/4.62 F cm⁻² at a current density of 1 A g⁻¹) and outstanding cycling stability (123.8% retention of the initial specific capacitance and ∼90.2% of the biggest capacitance at 10 A g⁻¹ after 10 000 cycles). An asymmetric supercapacitor (ASC) fabricated using stalactiform S-CoNi-rGO as the anode and activated carbon (AC) as the cathode achieves a high energy density of 114.03 W h kg⁻¹ at a power density of 0.85 kW kg⁻¹ (at a current density of 1 A g⁻¹). This study suggests that structural optimization can achieve high-performance supercapacitors.