Our work showcases a remarkable supercapacitor structure that utilizes pure Cu-MOF materials, with the goal of introducing promising supercapacitor materials. In this report, the symmetrical solid-state supercapacitors based on metal-organic framework (MOF) electrodes of Cu-BTC and Cu-BDC, respectively, in combination with coupling gel polymer electrolyte (GPE) of the PVA-LiCl-NaCl system, are studied under a high-temperature behavior measurement. The supercapacitors are based on electrodes composed solely of Cu-MOF material, and they perform on par with commercial carbon materials like graphite and charcoal. Additionally, the supercapacitor based on MOF electrodes exhibits good stability after a long time of 5000 charge-discharge cycles and high-temperature behavior at 100 °C. Notably, the supercapacitor devices exhibit the good electrochemical performances of 150 and 120 F g⁻¹ for Cu-BTC and Cu-BDC electrodes at 100 °C, respectively. First-principles calculations indicate that Cu-MOF electrodes are mechanically stable in PVA-LiCl-NaCl electrolyte and offer a great number of active Li/Na adsorption sites. Moreover, the adsorption of electrolyte ions enhances the pseudocapacitive behavior and electrolyte ion diffusion of Cu-MOF electrodes. This research focuses on the electrochemical ability directly related to thermal abuse via high-temperature behavior from the perspective of thermal runaway and supercapacitor safety. Thus, it provides an interesting view and a promising application for MOF materials in energy storage applications.
