Fabrication of Mesoporous Materials Based on Supramolecular Self-Assembly of Guanosine Monophosphonate-Nickel Chloride (GMP-Ni) for High-Performance Hybrid Supercapacitors

Supramolecular self-assembly of nickel chloride and guanosine mono-phosphonate (GMP) and nickel (Ni)-based GMP-Ni and their calcinated mesoporous electrode materials GMP-Ni-500 and GMP-Ni-700 at 500 and 700 °C, respectively, have been fabricated. GMP-Ni, GMP-Ni-500, and GMP-Ni-700 are examined for their supercapacitor performance in a three-electrode configuration. The electrochemical tests demonstrate the mesoporous battery-type nature of GMP-Ni-500 which exhibited a specific capacity (C_s) of about 289 C g^–1 at 0.5 A g^–1 current density. In addition, a cost-effective and simple asymmetric supercapacitor device has been fabricated with battery-type GMP-Ni-500 as a cathode material and capacitive-type activated carbon (AC) as an anodic material. In an operating voltage window of 0 to 1.5 V, hybrid supercapacitors (HSCs) based on GMP-Ni-500//AC exhibited a remarkable performance with a specific capacity (C_s) of 144 C g^–1 at 0.5 A g^–1. For the HSC device, the maximum of 66% capacity retention has been observed after 5000 charging/discharging cycles at 5 A g^–1. Furthermore, the HSC device demonstrates a high energy density of 24 W h kg^–1 at a power density of 297 W kg^–1. The molecular transformation was established by employing theoretical calculations. These results suggest that our HSC has outstanding potential in technology development for next-generation commercial applications.