In view of the ever-increasing demand for renewable energies, battery and energy storage/conversion research is of great importance to the research community. With scanning probe microscopies, the latest research questions can be tackled.
The research for new energy materials ranges from electrode material for batteries and fuel cells, novel catalysts, membrane materials or novel materials for energy storage, such as supercapacitors.
During the charging of Li-ion batteries, the formation of a solid-electrolyte interphase takes place on the anode surface. It consists of decomposed electrolyte molecules that start blocking the surface. The process is unavoidable, but limited to a finite thickness, because it is impenetrable for electrolyte molecules. The intercalation of Li-ions can still take place due to their small size.
With SECM, the formation of the SEI can be studied in-situ and its local properties are characterized with high lateral resolution. Doing this, questions such as the potential dependence on the SEI formation, film morphology, and electrical properties can be answered.
In search of new cathode active materials and in order to understand their electrochemical behavior better, scanning microdroplet contact method was employed to study single particle agglomerates of lithium iron phosphate.
In this method, a miniaturized electrochemical cell is formed by a droplet at the micropipette tip. Common electrochemical bulk techniques, such as CV, chronoamperometry or EIS can now be applied to the single particle agglomerate. This allows studying local properties and variations thereof. In this publication, the cathode material particles were drop-cast onto a glassy carbon surface to investigate their properties isolated from a binder.
Gateman, S. M., Halimi, I., Nascimento, A. R. C., Lacasse, R., Schulz, R., Moreau, C., Chromik, R. & Mauzeroll, J. (2019). Using macro and micro electrochemical methods to understand the corrosion behavior of stainless steel thermal spray coatings. npj Materials Degradation, 3(1), 25.
Mechanoelectrochemistry, with main focus of solving the electrochemical, mechanical and thermal failures in energy conversion and storage devices, is emerging as a new discipline based on the principles of electrochemistry and mechanics of materials. Pioneering research has demonstrated that scanning electrochemical microscopy (SECM) and scanning ion conductance microscopy (SICM) with Shear-force Sensing technique were highly effective metrics and methods to precisely quantify nanostructured morphology-dependent charge storage function and coupled volumetric mechanical strain simultaneously in situ for polymer membranes that were fabricated using phospholipid vesicles as soft-templates. Such a Surface-tracked SECM imaging and sensing techniques provide a unique breakthrough in the formation of profound rules to design nanostructured polymer-based actuators, energy storage devices and biological sensors.
Image by courtesy of Prof. Dr. Vishnu Baba Sundaresan, Department of Mechanical and Aerospace Engineering, Ohio State University, USA.