Novel isostructural iron‐series‐MOF calcined derivatives as positive and negative electrodes: A new strategy to obtain matched electrodes in a supercapacitor device

Abstract

Abstract The performance of asymmetric supercapacitors (ASCs) is strongly restricted by the capacity gap between the positive and negative electrodes. To address this issue, two new electrode materials deriving from Co‐ and Fe‐based metal–organic frameworks (MOFs, Co‐TAMBA‐d, and Fe‐TAMBA‐d) through a single‐step sintering method have been developed by considering the superiorities of the derivatives of MOFs including large surface areas, sufficient metal‐atom‐doping content, and extreme surface wettability to the bath solution. The as‐prepared Co‐TAMBA‐d as a positive electrode delivers typical pseudocapacitive behavior with the improvement of capacity, which is better than those of pristine MOF materials, while Fe‐TAMBA‐d as negative electrodes displays better electrochemical behavior than those of activated carbon. ASCs based on these two electrodes exhibits excellent energy density and power density of 47 W h/kg and 1658 W/kg, respectively, where this device can maintain prominent cycling stability with capacity retention after 5000 cycles being about 75%. Furthermore, the capacity can feed a series of red light‐emitting diodes, which gives solid evidence of the potential utilization. These results can afford the feasibility of isostructural MOF derivatives as promising electrodes in novel ASCs.

Keywords

• asymmetric supercapacitor
• Co‐ and Fe‐based MOFs
• isostructural MOFs
• MOF derivatives