ABSTRACT
Prussian blue and its analogues have a perovskite related structure, where transition metals are bridged by cyanide. For high charge/discharge-rate operation, poor ion diffusivity and poor electronic conductivity of Prussian Blue Analogues (PBAs) frameworks are main obstacles, because a resulting large resistance within the electrode substantially degrades battery efficiency. Lithium-ion batteries are state-of-the-art electrochemical energy storage devices, which are commercialized mainly for portable electronics, because of their relatively high gravimetric/volumetric-energy densities. Aqueous batteries are the other important target for large-scale application, because aqueous electrolytes are expected to reduce a total battery cost drastically. To summarize, the electrode performance of PBAs is essentially governed by various factors such as the constituent transition metals, the amount of vacancies, the intercalants, the particle size, and the electrolytes. In this context, a wide range of approaches has been exploited to improve the PBA electrode performance.
