Synthesis of cobalt-iron selenide graphene-carbon nanotube composite with 3D layered structure using the spray pyrolysis process and evaluation of anode characteristics of potassium ion battery

The irreversible aggregation of graphene due to strong van der Waals interactions remains a critical challenge in the development of high-performance electrode materials. In this study, a novel three-dimensionally hybridized composite microsphere consisting of reduced graphene oxide (rGO), carbon nanotubes (CNTs), and cobalt–iron selenide (Co–Fe–Se) nanocrystals was synthesized for the first time using a combination of aerosol-assisted spray pyrolysis and chemical vapor deposition (CVD). Crumpled rGO microspheres were initially formed via spray pyrolysis to mitigate graphene restacking and enhance structural stability. Vertically grown CNTs on the rGO surface acted as barriers to further aggregation while providing continuous conductive pathways for efficient electron transport. Co–Fe alloy nanocrystals were subsequently converted into Co–Fe–Se through selenization, significantly improving potassium-ion storage capacity. The resulting rGO–CNT–(CoFe)Se_x composite exhibited superior structural integrity, electrical conductivity, and electrochemical performance compared to conventional composites. Furthermore, the electrode demonstrated excellent compatibility with various electrolyte systems, indicating its potential for practical applications. The hybrid design offers a synergistic combination of high surface area, stable framework, and efficient ion/electron transport pathways, contributing to enhanced cycling stability and capacity retention. This study presents a promising strategy for the development of advanced anode materials for next-generation energy storage systems, particularly potassium-ion batteries, and highlights the potential of hybrid graphene-based architectures for overcoming aggregation-related limitations in electrode design.

Mr. Jae Won Lee graduated from the Department of Advanced Materials Engineering at Chungbuk National University. He is currently pursuing a master’s degree in Materials Engineering at the same university. His research focuses on the synthesis of nanomaterials via aerosol-assisted processes and their applications in various fields, particularly in energy storage, including next-generation batteries and advanced cathode and anode materials.