Boosting the electrochemical performance of Prussian-Blue-analogue based Li-ion rechargeable batteries by the addition of Ag or Ni nanoparticles into the cathode

The poor cyclability of Prussian-blue-analogue (PBA) based rechargeable Li-ion batteries places a limitation on their practical applications. Here, we demonstrate that the addition of bare Ag or Ni nanoparticles (NPs) into the vicinity of the nano-sized PBA particles can effectively improve the electrochemical performance of the batteries, leading toward a higher energy storage capacity. The addition of 14 mass-percent of 13.6 mm Ag NPs into the vicinity of the 120 nm K_0.58Co[Co(CN)₆] NPs gives rise to a 260 % increase in the stabilized full specific capacity C_F, and the addition of 14 mass-percent of 12.4 nm Ni NPs gives rise to an 86 % increase of the stabilized C_F. The addition of Ag or Ni NPs was also found to enhance the C_F for the 80 nm Na_0.46Co[Fe(CN)₆]-based Li-ion batteries but the effect was smaller. It is the participations of the redox reactions of weakly bonded surface electrons on the Ag/Ni NPs that enhances the energy storage capacity of the battery.