Potassium (De‐)insertion Processes in Prussian Blue Particles: Ensemble versus Single Nanoparticle Behaviour

Abstract Potassium (de‐)insertion from Prussian blue (PB) is investigated at the single and multi‐particle scale. The electrochemical behaviour is found to differ between the two measurement types. At the single particle level, oxidation of the PB nanoparticles with concomitant K + deinsertion occurs more readily than the associated reduction, relating to K + insertion. In contrast, the cyclic voltammetry of PB in a composite electrode containing conductive additives and polymeric binder suggests the opposite behaviour. Implications for assessing battery materials are discussed.