Cobalt/Nitrogen Co‐Doped Carbon Materials Enhance the Reaction Rate of Sodium–Potassium Alloy Electrodes

Abstract Sodium–potassium (NaK) alloy electrodes are ideal for next‐generation dendrite‐free alkali metal electrodes due to their dendrite‐free nature. However, issues such as slow diffusion kinetics due to the large K⁺ radius and the loss of active potassium during the reaction severely limit its application. Here a novel cobalt/nitrogen‐doped carbon material is designed and it is applied to the construction of a NaK alloy electrode. The experimental and theoretical results indicate that the confining effect of the nitrogen‐doped graphitic carbon layer can protect the cobalt nanoparticles from corrosion leaching, while the presence of Co─N_x bonds and cobalt nanoparticles provides more active sites for the reaction, realizing the synergistic effect of adsorption‐catalytic modulation, lowering the K⁺ diffusion energy barrier and promoting charge transfer and ion diffusion. The application of this electrode to a symmetrical battery can achieve more than 1800 stable cycles under a current density of 0.4 mA cm⁻² and a charge/discharge specific capacity of 122.64 mAh g⁻¹ under a current of 0.5C in a full battery. This finding provides a new idea to realize a fast, stable, and efficient application of NaK alloy electrodes.