Controlled Selenium Infiltration of Cobalt Phosphide Nanostructure Arrays from a Two-Dimensional Cobalt Metal–Organic Framework: A Self-Supported Electrode for Flexible Quasi-Solid-State Asymmetric Supercapacitors
Kisan Chhetri, Bipeen Dahal, Arjun Prasad Tiwari, Tanka Mukhiya, Alagan Muthurasu, Gunendra Prasad Ojha, Minju Lee, Taewoo Kim, Su‐Hyeong Chae, Hak Yong Kim
Abstract
Various hybrid materials containing transitional metals (TMs) with selenium (Se) have been widely studied, but the controlled infiltration of Se in a cobalt phosphide nanostructured array (CPNA) derived from a two-dimensional cobalt metal–organic Framework (2D Co-MOF) is the different approach of material design for energy storage applications. In this work, 2D Co-MOF arrays are successfully grown on an activated carbon fiber textile (ACFT) and converted into Se x @CPNA-ACFT through successive phosphidization and selenium infiltration processes under the optimized conditions. In the three-electrode system, Se 0.6 @CPNA-ACFT shows a higher specific capacity of ∼302 mAh g –1 and excellent cycling stability with a capacity retention of ∼93.8% after 10,000 cycles. The flexible quasi-solid-state asymmetric supercapacitor (ASC) based on Se 0.6 @CPNA-ACFT as a positive electrode and FeS 2 decorated reduced graphene oxide at etched CFT (FeS 2 @rGO-ECFT) as a negative electrode exhibits a maximum energy density of ∼70.6 Wh kg –1 (volumetric energy density of ∼1.81 mWh cm –3 ) and a maximum power density of 8.163 kW kg –1 with remarkable stability. This work provides a good example of the rational modification of a 2D Co-MOF into an efficient Se 0.6 @CPNA-ACFT electrode material for a high-performance quasi-solid-state flexible ASC for future energy storage applications.