Application of metal oxide/porous carbon nanocomposites in electrochemical capacitors: A review

In the past decade, electrochemical capacitors (ECs) have emerged as innovative energy storage devices, attracting considerable interest from both industrial and academic sectors due to their prolonged cyclic stability and impressive power density. Recently, there has been a focus on advancing high-performance ECs by developing electrode material composed of metal oxide incorporated with porous carbon. Integrating metal oxides into a porous carbon structure enhances capacitance, charge storage, and cyclic stability. Furthermore, the porous structure inherent in carbon materials offers efficient ion diffusion and large surface area, thereby augmenting the overall effectiveness of the nanocomposites. Efficient electron and ion transport within the electrode's bulk is achieved through the interaction between electrodes and electrolytes occurring at the electrodeelectrolyte interface, subsequently increasing the capacitance. This paper summarizes the latest developments in ECs, focusing on key performance metrics such as cyclic stability and capacitance. It also summarizes the recent advancements made in electrode materials, emphasizing the utilization of sustainable feedstocks. As the research landscape shifts towards more environmentally friendly solutions, the incorporation bio-materials into electrode design has gained significant attention. It particularly highlights underlying mechanisms governing the performance of metal oxides/porous carbon nanocomposites in ECs and outlines future research directions aimed at maximizing their potential for next-generation energy storage devices. Additionally, the paper delves into the possibilities and challenges associated with the preparation, and optimization of the structure of metal oxide electrodes incorporating porous carbon to improve energy storage performance in ECs.