Designing of the CoFeX (X= Se, P, S) Flower-like Structures on Nickel Foam as Efficient Positive Electrodes for a High-Performance Hybrid Supercapacitor
Majid Shirvani, Saied Saeed Hosseiny Davarani
Abstract
The utilization of supercapacitive active bimetallic cobalt-iron selenides/phosphides/sulfides (CoFeX = Se, P, S) as active energy storage materials in supercapacitors still has space for betterment owing to low specific capacity and reduces the electrochemical performance during long-term application. This paper describes a facile and cost-effective strategy to substantially improve the specific capacity and durability of flower-like CoFeX (X = Se, P, S)@NiF by substituting Se, P, and S elements into the cobalt-iron hydroxide precursor, respectively. The CoFe 2 Se 4 @NiF electrode showed better capacitive activity than CoFeP@NiF and CoFeS 2 @NiF electrodes. The CoFe 2 Se 4 @NiF electrode shows remarkable supercapacitive properties with a specific capacity of 338.78 mA h/g (1219.61 C/g) at 1 A/g, a significant rate capability of 83.14% at 20 A/g, and remarkable durability (8.06% capacity decline after 10,000 cycles). Also, the fabricated CoFe 2 Se 4 @NiF(positive)//AC@NiF(negative) hybrid supercapacitor by utilizing the CoFe 2 Se 4 @NiF as a satisfactory positive electrode and activated carbon on the nickel foam (AC@NiF) as a favorable negative electrode reflected an excellent energy density of 61.40 W h/kg at 799.85 W/kg and an excellent durability of 94.45% after 10,000 cycles.