P-062

Dovile Škarnulytė1,2

dovile.skarnulyte@chgf.vu.lt

Jurgis Pilipavičius2, Linas Vilčiauskas2

1Institute of Chemistry, Vilnius University, Lithuania

2Centre for Physical Sciences and Technology (FTMC), Vilnius, Lithuania

Synthesis and application of zinc hexacyanoferrate in aqueous zinc-ion batteries

The necessity to develop energy storage devices such as batteries is growing as the world's demand for energy from renewable sources increases. Aqueous zinc-ion batteries (AZIBs) have gained a lot of attention due to their environmentally benign nature compared to the most commonly used lithium-ion batteries. A promising cathode material in AZIB systems is a Prussian blue analogue zinc hexacyanoferrate (ZnHCF), which can have cubic and rhombohedral structures. The open framework structure of ZnHCF allows the intercalation of various metal ions such as K+, Na+, Zn2+. However, the practical implementation of these batteries faces challenges, including the unclear influence of synthesis parameters on the phase composition of ZnHCF and the poorly understood Zn-ion intercalation/deintercalation mechanism.

This study aims to address these limitations by: a) Determining synthesis conditions that favor the formation of orthorhombic ZnHCF and identifying factors contributing to cubic and pseudo-cubic phase formation. b) Investigating the charge/discharge processes through operando X-ray diffraction (XRD) and ex-situ techniques such as Fourier transform infrared (FTIR) spectroscopy and Raman spectroscopy. Study showed, that drying conditions of synthesized ZnHCF play a major role in the phase formation process. Furthermore, operando XRD analysis revealed a more complex phase transition mechanism than previously understood. These findings contribute to a deeper understanding of the structural and electrochemical behavior of ZnHCF, offering valuable insights for optimizing its performance as a cathode material in safer and more sustainable aqueous zinc-ion battery systems.