Sample dependent performance of aqueous copper hexacyanoferrate/zinc batteries

Abstract

The performance of aqueous CuHCF/Zn batteries are highly dependent on the CuHCF sample. With Na-based electrolyte the capacity retention improves at low pH, whereas cells with Zn-based electrolyte have similar performance at pH 2 and pH 4.

Abstract

In this work, we investigate factors affecting the capacity retention of aqueous copper hexacyanoferrate/Zn batteries. We compare the performance of four different copper hexacyanoferrate (CuHCF) samples as cathode in CuHCF/Zn cells with Na ₂SO ₄ and ZnSO ₄ based electrolytes at different pH. In Na ₂SO ₄ electrolyte, the capacity retention is improved at lower pH, whereas cells with ZnSO ₄ electrolyte perform similarly at pH 2 and 4. Finally, we show that the performance of CuHCF/Zn cells is highly dependent on the CuHCF sample, underlining the necessity for detailed synthesis description and thorough structural characterization of electrode materials.