Synchrotron-tailored hierarchical carbon nanofibers with ZnO decoration for long-lifespan potassium metal batteries

Abstract

Potassium metal batteries (KMBs) are a strong alternative to lithium-ion batteries due to their high energy density and low cost. However, uneven potassium deposition and dendrite growth can lead to short circuits, limiting their application. Research has demonstrated that loading potassium onto appropriate carriers such as porous carbon nanofibers (CNFs) can effectively suppress dendrite formation. In this study, we develop a dendrite-free potassium metal composite anode material, ZnO@CNFs, with porous CNFs as the conductive framework, to regulate potassium deposition via conversion reactions. We used cutting-edge analytical techniques and theoretical computations to explore the mechanism for enhancing K⁺ deposition in the pores and improving electrolyte wetting efficiency in high-porosity structures. The spatial distribution of the ZnO component, coupled with its potassium-affinitive properties, generates a synergistic effect, effectively promoting the interface insertion/extraction dynamics of K⁺. These innovative approaches offer a significant technological pathway for the development of long-cycle-life KMBs.