Operando Heating and Cooling Electrochemical 4D-STEM Probing Nanoscale Dynamics at Solid-Liquid Interfaces
Sungin Kim1, Valentin Briega-Martos1, Shikai Liu1
1Department of Chemistry and Chemical Biology, Baker Lab, Cornell University, Ithaca, New York 14853, United States.
Journal of the American Chemical Society
|May 23, 2025
Summary
We developed a new operando heating and cooling electrochemical liquid-cell scanning transmission electron microscopy (EC-STEM) to study nanoscale electrochemical processes. This powerful tool allows for precise control of temperature and electrochemistry, enabling the investigation of energy materials in extreme climates.
Area of Science:
- Materials Science
- Electrochemistry
- Analytical Chemistry
Background:
- Operando/in situ methods, such as transmission electron microscopy (TEM), allow real-time observation of chemical and structural changes at interfaces.
- Existing electrochemical liquid-cell TEM often lacks simultaneous thermal control, limiting studies of materials under varying temperatures.
- Understanding nanoscale electrochemical dynamics under diverse thermal conditions is crucial for developing advanced energy technologies.
Purpose of the Study:
- To develop and demonstrate an operando heating and cooling electrochemical liquid-cell scanning TEM (EC-STEM) system.
- To investigate the temperature dependence of electrochemical processes and material growth at the nanoscale.
- To enable the study of energy materials under realistic, extreme climate conditions.
Main Methods:
- Integration of a three-electrode electrochemical circuit and a two-electrode thermal circuit into a liquid-cell scanning TEM.
- Utilizing copper electrodeposition/stripping as a model system for quantitative electrochemistry from -40 to 95 °C.
- Employing machine learning-assisted quantitative 4D-STEM for structural analysis at -40 °C.
Main Results:
- Demonstrated quantitative electrochemistry in aqueous and organic solutions across a wide temperature range (-40 to 95 °C).
- Observed a distinct two-stage growth mechanism of copper nanostructures (mossy islands followed by dendrites) at -40 °C.
- Characterized the temperature and pH dependence of a platinum pseudoreference electrode, confirming its stability.
Conclusions:
- The developed operando heating/cooling EC-STEM is a powerful tool for fundamental nanoscale electrochemistry research.
- This technique facilitates the investigation of energy materials operating in extreme climates, advancing battery and catalyst technologies.
- The findings provide insights into temperature-controlled nanoscale electrochemical phenomena and material morphology evolution.
