Nonaqueous potassium-ion full-cells: Mapping the progress and identifying missing puzzle pieces

This review addresses the growing interest for potassium-ion full-cells (KIFCs) in view of the transition from potassium-ion half-cells (KIHCs) toward commercial K-ion batteries (KIBs). It focuses on the key parameters of KIFCs such as the electrode/electrolyte interfaces challenge, major barriers, and recent advancements in KIFCs. The strategies for enhancing KIFC performance, including interfaces control, electrolyte optimization, electrodes capacity ratio, electrode material screening and electrode design, are discussed. The review highlights the need to evaluate KIBs in full-cell configurations as half-cell results are strongly impacted by the K metal reactivity. It also emphasizes the importance of understanding solid electrolyte interphase (SEI) formation in KIFCs and explores promising nonaqueous as well as quasi- and all-solid-state electrolytes options. This review thus paves the way for practical, cost-effective, and scalable KIBs as energy storage systems by offering insights and guidance for future research.