Imaging accumulated charges at solid-electrolyte interfaces

October 02, 2018

Kanazawa, Japan--Charges and their transport are integral to the function of electronic devices, batteries, and biological systems. The charges that accumulate at the interface between a solid electrode and an electrolytic solution containing ions that carry charges, can affect the electrode-electrolyte interaction as well as processes such as corrosion and molecular adhesion. Consequently, it is important to obtain a clear picture of accumulated charges at such interfaces to improve our understanding of interfacial phenomena in a variety of systems. However, imaging the three-dimensional (3D) spatial distribution of accumulated charges at interfaces has been difficult because it is challenging to measure the lateral charge distribution at a solid-liquid interface.

A team based at Kanazawa University has developed a microscopy approach called 3D open-loop electric potential microscopy (OL-EPM) to visualize the real-space charge distribution at the interface between an electrode and electrolyte. The researchers developed 3D OL-EPM by first optimizing their existing two-dimensional OL-EPM technique.

"Conventional OL-EPM is limited by influence of the long-range interaction between the sample and microscope tip and cantilever," says the first author Kaito Hirata. "We minimized this influence by improving the equations used to calculate the potential in OL-EPM."

These improved equations enabled to subtract the long-range force acting on the microscope tip and cantilever from the measured data. As a result, the short-range forces originating from charges accumulated in the electric double layer were observed as changes of the local surface potential. The ability of the improved equations to calculate interfacial charge distributions was determined using two electrodes with different charge accumulation behavior. The opposite charge accumulation characteristics at the two electrodes were successfully captured using the improved OL-EPM equations.

The improved OL-EPM approach was then combined with a 3D tip scanning technique to provide 3D OL-EPM. The team used 3D OL-EPM to visualize the charge accumulation at the interface between a copper wire electrode and salt electrolyte. The obtained results provided valuable information about the charge distribution at the electrode-electrolyte interface.

"We can use 3D OL-EPM to investigate electrochemical reactions and local solution conditions at electrode-electrolyte interfaces," explains the corresponding author Takeshi Fukuma. "The information obtained from such experiments is important for fields such as electrochemistry, electronics, and biology."

The ability to obtain real-space data about the nanoscale charge distribution at electroactive interfaces promises to increase our understanding of interfacial phenomena and aid progress in electronics and battery research.

Kanazawa University

Related Electronics Articles from Brightsurf:

Artificial materials for more efficient electronics
The discovery by a team of the University of Geneva of an unprecedented physical effect in a new artificial material marks a significant milestone in the lengthy process of developing ''made-to-order'' materials and more energy-efficient electronics.

The new tattoo: Drawing electronics on skin
One day, people could monitor their own health conditions by simply picking up a pencil and drawing a bioelectronic device on their skin.

Lighting the way to porous electronics and sensors
Researchers from Osaka University have created porous titanium dioxide ceramic thin films, at high temperatures and room temperature.

The ink of the future in printed electronics
A research group led by Simone Fabiano at the Laboratory of Organic Electronics, Linköping University, has created an organic material with superb conductivity that doesn't need to be doped.

Integrating electronics onto physical prototypes
MIT researchers have invented a way to integrate 'breadboards' -- flat platforms widely used for electronics prototyping -- directly onto physical products.

Something from nothing: Using waste heat to power electronics
Researchers from the University of Tsukuba developed an improved thermocell design to convert heat into electricity.

Electronics at the speed of light
A European team of researchers including physicists from the University of Konstanz has found a way of transporting electrons at times below the femtosecond range by manipulating them with light.

Electronics integrated to the muscle via 'Kirigami'
A research team in the Department of Electrical and Electronic Information Engineering and the Electronics-Inspired Interdisciplinary Research Institute (EIIRIS) at Toyohashi University of Technology has developed a donut-shaped kirigami device for electromyography (EMG) recordings.

Creating 2D heterostructures for future electronics
New research integrates nanomaterials into heterostructures, an important step toward creating nanoelectronics.

Researchers report a new way to produce curvy electronics
Contact lenses that can monitor your health as well as correct your eyesight aren't science fiction, but an efficient manufacturing method has remained elusive.

Read More: Electronics News and Electronics Current Events is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to