Peripheral octamethyl-substituted nickel(II)-phthalocyanine-decorated carbon-nanotube electrodes for high-performance all-solid-state flexible symmetric supercapacitors

Construction of advanced electrode materials with unique performance for supercapacitors (SCs) is essential to achieving high implementation in the commercial market. Here, we report a novel peripheral octamethyl-substituted nickel(II) phthalocyanine (NiMe2Pc)-based nanocomposite as the electrode material of all-solid-state SCs. The highly redox-active NiMe2Pc/carboxylated carbon nanotube (CNT-COOH) dendritic nanocomposite provides rapid electron/electrolyte ion-transport pathways and exhibits excellent structural stability, resulting in high-capacity activity and impressive cycling stability. The com-posite prepared with the optimized weight ratio of NiMe2Pc:CNT-COOH (6:10) showed the highest speci-fic capacitance of 330.5 F g-1 at 0.25 A g-1. The constructed NiMe2Pc/CNT-COOH-based all-solid-state symmetric SC device showed excellent performance with a maximum energy density of 22.8 Wh kg-1 and outstanding cycling stability (111.6% retained after 35,000 cycles). Moreover, flexible carbon cloth significantly enhanced the energy density of the NiMe2Pc/CNT-COOH all-solid-state symmetric device to 52.1 Wh kg-1 with 95.4% capacitance retention after 35,000 cycles, and it could be applied to high -performance flexible electronics applications. These findings provide a novel strategy to design phthalocyanine-based electrode materials for next-generation flexible SC devices.(c) 2022 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by ELSEVIER B.V. and Science Press. All rights reserved.

Automated summary

This study reports a novel nanocomposite based on octamethyl-substituted nickel(II) phthalocyanine as the electrode material for all-solid-state supercapacitors. The nanocomposite provides rapid electron and electrolyte ion transport pathways, excellent structural stability, and high-capacity activity. The optimized weight ratio of the composite exhibits the highest specific capacitance and impressive cycling stability. In addition, flexible carbon cloth enhances the energy density and capacitance retention of the device, making it suitable for flexible electronics applications.