Development and Implementation of In Situ Mossbauer Spectrometry for the Study of Battery Cathode Materials

Mossbauer Spectroscopy has proven to be a very useful tool for studying the local electron dynamics in iron-containing battery materials. In the hunt for more economical and sustainable battery cathode materials, NaFePO4 has emerged as a lower-cost and safer alternative to LiFePO4. We report the development and characterization of an electrochemical cell for in situ Mossbauer spectroscopy measurement. The in situ setup is used to study changes in the local structure of iron atoms during initial discharge and charge in NaFePO4 half-cells. We will compare these results to previous in situ studies of LiFePO4. Finally we will compare the initial charge and discharge spectra to those after multiple cycles to provide insights into changes in the cathode material that may result in cell degradation.