Zinc-based energy storage with functionalized carbon nanotube/polyaniline nanocomposite cathodes

Abstract

Aqueous zinc-based electrochemical energy storage (EES) systems including zinc-ion batteries and zinc-ion hybrid supercapacitors are increasingly studied, due to their great potential for safe, high-power and wearable energy storage. The electrochemical performance of zinc-based EES systems is strongly affected by cathode materials. Herein, functionalized carbon nanotube (f-CNT)/polyaniline (PANI) nanocomposites were synthesized by in-situ polymerization of PANI on f-CNTs and then used as cathode materials for zinc-based EES systems. Benefiting from better hydrophilicity and chemical adsorption ability of Zn2+, f-CNTs are superior to pristine CNTs in electrochemical performance, and the f-CNT/PANI nanocomposites effectively integrated capacitive energy storage mechanism of f-CNTs with redox reaction energy storage mechanism of PANI, thereby exhibiting superior comprehensive electrochemical properties including high capacity, good rate performance and long cycle life. Moreover, high-performance and flexible zinc-based EES devices were constructed with the f-CNT/PANI nanocomposite cathodes. This work is expected to provide new thoughts to achieve high-performance and flexible zinc-based EES.