Electrodeposited NiFe2Se4 on Nickel Foam as a Binder-Free Electrode for High-Performance Asymmetric Supercapacitors

Preparation of electrode materials with rich redox peaks, fast ion-passage channels, and excellent cycling stability through a cost-effective process is vitally important for supercapacitors (SCs). In this work, we successfully fabricated a bimetallic selenide NiFe2Se4 through a simple and low-cost electrodeposition method. The resulting NiFe2Se4 electrode prepared at an optimized condition delivers a high specific capacity (372.2 mAh g–1 at 1 A g–1) and desirable cycling stability. Besides, the assembled NiFe2Se4//AC asymmetric supercapacitor (ASC) achieves a high operating voltage (1.6 V) with a maximum energy density of 45.6 Wh kg–1 and an outstanding cycling stability (maintains 101.4% of its original capacitance value after 10 000 cycles). Owing to the superior electrochemical performance, the NiFe2Se4//AC ASCs can light up a red light-emitting diode (LED) for real-time application.