Revealing the distribution of fluorine in battery cathodes with EDS and WDS mapping

Instruments used

EDAX^® Neptune (EDS-WDS) system

Background

Incorporating fluorine into the cathode structure of a lithium-ion battery is a strategic way to engineer F-rich interfaces that can significantly boost electrochemical performance. Fluorine is added in small amounts (<0.2 at.%) to improve the cathode’s voltage, stability, and capacity retention during charging and discharging cycles. At higher concentrations, the formation of a separate, less-effective LiF phase may be formed. Therefore, it is important to understand the fluorine distribution at minor or trace concentrations to provide valuable guidance in the development of improved battery cells.