In‐Situ Preparation of Iron(II)‐phthalocyanine@multi‐Walled‐CNTs Nanocomposite for Quasi‐Solid‐State Flexible Symmetric Supercapacitors with Long Cycling Life

Abstract

The construction of supercapacitor electrode materials with exceptional performance is the crucial to the commercialisation of flexible supercapacitors. Here, a novel in‐situ precipitation technique was applied for constructing iron(II)‐phthalocyanine (FePc) based nanocomposite as the electrode material in quasi‐solid‐state flexible supercapacitors. The highly redox‐active FePc nanostructures were grown in the multi‐walled‐CNTs (MWCNTs) networks, which shows convenient electron/electrolyte ion transport pathways along with outstanding structural stability, leading to high energy storage and long cycling life. The electrode of FePc@MWCNTs delivered a higher specific capacity than that of individual MWCNTs and FePc. The quasi‐solid‐state symmetric flexible device that was constructed using FePc@MWCNTs electrode demonstrated impressive performance with a maximum energy density of 29.7 Wh kg−1 and a maximum power density of 4000 W kg−1. Moreover, the device demonstrated superior durability and flexibility, as evidenced by its exceptional cyclic stability (111.3%) even after 30000 cycles at 8 A g−1. These results reveal that the FePc@MWCNTs nanocomposite prepared by this simple in‐situ precipitation method is promising as electrode material for next‐generation flexible wearable power sources.