Speaker
Description
Dissolution of redox-active organic electrode materials into the electrolyte is a major limitation for the long-term stability of organic batteries. However, directly monitoring dissolved species during battery operation remains challenging because conventional ex situ measurements cannot fully capture their temporal and spatial evolution. In this work, we present a spatially resolved operando synchrotron Fourier-transform infrared spectroscopy methodology for investigating electrode dissolution under electrochemical operating conditions.
1,4,5,8- naphthalenetetracarboxylic dianhydride-derived polyimide (PNTCDA) was selected as a model organic electrode material in a lithium half-cell containing 1 M LiTFSI in DME electrolyte. Repeated synchrotron FTIR mapping was performed across selected regions of the electrochemical cell while the electrochemical response was recorded simultaneously. The high brightness and spatial resolution of synchrotron radiation enable changes in characteristic molecular vibrations to be monitored as a function of position, time, and electrochemical state. Spectral preprocessing, peak tracking, and band-area analysis are used to distinguish electrolyte-related signals from spectral features associated with PNTCDA and its electrochemically generated dissolved species.
This methodology provides a framework for correlating the spatial distribution and evolution of dissolved species with electrochemical processes. Although demonstrated using PNTCDA, the developed approach can be extended to other organic and inorganic materials to investigate dissolution mechanisms, reaction intermediates, and electrode–electrolyte interactions under realistic operating conditions.