Dual Room Temperature Liquid Metal Derived Non‐Newtonian Potassium‐Ion Battery Anode: Regulation of Viscoelastic Behavior

ABSTRACT Room temperature liquid metals (RTLMs) are promising anode candidates for alkali metal batteries due to their high conductivity and fluidity, but they suffer from critical challenges, including high surface tension, excessive viscosity, and dendrite growth. Herein, a novel non‐Newtonian fluid electrode construction strategy is proposed via liquid‐liquid interfacial reactions between NaK alloy and GaInSn alloy, without solid supports. The formation of Ga 4 Na intermetallic compounds regulates the rheological properties, enabling faster reaction kinetics and superior compositional uniformity compared to liquid‐solid composite systems, while avoiding oxide/hydroxide induced high viscosity. Notably, the formation of non‐Newtonian fluids through liquid‐liquid reaction induced intermetallic compounds for K‐ion battery anodes is not previously reported. This work provides a new solution to the high surface tension issue of liquid metal anodes, paves the way for dendrite‐free, stable, and low viscosity alkali metal electrodes, and holds significant implications for flexible energy storage devices.