Improved Thermal Cyclability of Tertiary Battery Made of Prussian Blue Analogues

摘要

Tertiary battery is charged by the environmental heat, not by the electric energy, by using the difference (Δα) in the thermal coefficient (α=dV/dT) of redox potential (V) between the anode and cathode materials. The thermal cyclability is not good in the prototypical NaxCo[Fe(CN)6]0.71 (NCF71)/NaxCo[Fe (CN)6]0.90 (NCF90) tertiary battery. Here, we significantly im- proved the thermal cyclability of the tertiary battery with using Ni-substituted NaxNi[Fe(CN)6]0.68 (NNF68). The Ni-substituted NNF68/NCF90 tertiary battery shows good thermal cyclability: both the cell voltage and capacity essentially unchanged up to the 10th thermal cycles.