Solid–liquid interfaces play a central role in sustainable energy technologies, where interfacial structure, charge transfer, mass transport, and mechanical adaptability jointly determine electrochemical activity and stability. However, the rational construction of dynamic solid–liquid interfaces across multiple length scales remains challenging, especially for multicomponent catalytic materials and highly reactive alkali metal anodes. Here, I present two representative strategies based on liquid-metal-mediated interfacial regulation for energy conversion and storage systems.

First, a dynamic carbon/liquid gallium interface was developed for the controllable synthesis of multicomponent and high-entropy electrocatalysts. Conductive carbon paper was used as both an electron-transport framework and an interfacial support. Under an applied electric field, bulk liquid gallium was dispersed into submicron droplets and stably anchored on carbon fibers, greatly increasing the accessible liquid-metal surface area. The native gallium oxide layer on liquid gallium showed strong affinity toward various metal ions and oxides, enabling the interfacial anchoring, co-growth, and atomic-scale mixing of multiple metal species. This strategy allowed the in situ formation of ultrathin high-entropy oxide layers and overcame the phase separation and poor controllability commonly encountered in low-dimensional high-entropy material synthesis. Experimental characterization and density functional theory calculations further revealed strong coupling between the gallium oxide interface and the high-entropy catalytic layer. Such interfacial interaction stabilized the catalyst structure during electrochemical operation and introduced strain/electronic modulation that lowered reaction barriers and improved oxygen evolution kinetics. This liquid-metal interface concept was further extended to the universal synthesis of multicomponent high-entropy sulfide hollow nanostructures with promising electrochemical performance.

Second, a “semi-liquid anode” concept was proposed to stabilize sodium and potassium metal deposition. In this design, a thin liquid Na–K alloy layer was constructed in situ on the surface of a solid Na or K metal anode. The liquid alloy layer formed a dynamic and self-adaptive interface with the electrolyte, which homogenized interfacial ion flux, suppressed dendrite nucleation and growth, and mitigated interfacial instability. Meanwhile, the inner solid metal served as both a mechanical support and a continuous Na/K reservoir, avoiding the leakage and volume instability problems of fully liquid metal anodes. This solid–liquid hybrid structure enabled long-term stable cycling in Na/K metal batteries and demonstrated broad applicability in related alkali-metal electrode systems.

Overall, these studies highlight the importance of dynamic solid–liquid interface engineering in regulating nucleation, growth, charge redistribution, and structural evolution in electrochemical systems. By integrating liquid-metal chemistry, conductive solid supports, and multiscale interfacial characterization, this work provides new insights into the design of adaptive interfaces for high-performance catalysts and stable metal anodes, offering a general platform for sustainable energy conversion and storage technologies.