Achievements, challenges, and stability of layer double hydroxide and carbon nanotube hybrid electrode materials for clean and sustainable energy storage supercapacitor application: an extensive review

Abstract

Considering the massive environmental concerns due to air and water pollution, exhaustion of natural sources and global warming, awareness of environmental protection is required. In this case, a disruptive method to develop sustainable energy storage systems in the form of electrochemical energy storage (EES) devices is urgent. Supercapacitors or ultracapacitors are one the best long-standing passive electronic devices that can deliver maximum power and energy density. Accordingly, in the energy field, there has been increasing interest in their charging/discharging power, with research focusing on their cost, environmental friendliness, toxicity, portability, safety, service life, and disposal. Significant research has been conducted on layered double hydroxide (LDH) and carbon nanotube (CNT) composites for the design and fabrication of electrodes, with a focus on electrolyte operating window potential and cell temperature. The aim of this review is to highlight the extraordinary properties of supercapacitors (SCs) in terms of their physical, chemical and electrochemical performances. Importantly, this review offers insights into some of the key LDH/CNT nanocomposite SC electrodes. The fundamental storage mechanism, advantages and drawbacks of LDH/CNT composites together with their popularity, physicochemical techniques, applications, environmental conditions, challenges and future perspectives are elaborated. We hope that this review will encourage the research community and will enhance the results with comparative challenges.