Highly Dispersed Cobalt Nanoparticles Embedded in Nitrogen-Doped Graphitized Carbon for Fast and Durable Potassium Storage

Small cobalt nanoparticles are carefully encapsulated into a N-doped carbon shell (Co-NC) by calcining a Prussian blue analogue precursor. The presence of cobalt nanoparticles and Co-N bonds not only promotes adsorption behavior, but also reduces the diffusion energy barrier, enabling fast diffusion kinetics of K + ions. The good diffusion kinetics and capacitive adsorption behavior of the Co-NC material synergistically contributes to enhanced potassium storage performances.