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Charge Photometry
Illuminating operating batteries

How does it work?

Charge photometry is a light scattering microscopy technique that visualizes state-of-charge changes in individual active particles during battery cycling.


It exploits the principles of optical interference reflection microscopy to detect scattered light from the active particles. Ion insertion and extraction in the active particles give rise to changes in the detected optical contrast, reporting on the local state-of-charge.


Critically, this universal principle means that the charge photometry is agnostic to the underlying battery chemistry and can be applied to a wide range of materials.


How do you run the experiment?


The electrode stack is assembled into a custom-designed optically-accessible coin cell, which is mounted into the illumionONE.


Electrochemical testing protocols are set up in the acquisition software and applied to the cell by the integrated cycler of the illumionONE.


Over the course of the measurement, the illumionONE collects charge photometry information and morphological data for the particles, alongside the synchronized electrochemistry data.

What can I get out of
charge photometry?

The ability to observe state-of-charge changes under operando conditions on an individual particle level across a battery electrode unlocks a wide range of opportunities.

Electrode Optimization

Discover how much of your material is active and where performance is lost.


Discover what limits your charging rate performance on the active particle level.



Discover the processes leading to accelerated capacity loss.

A detailed account can be found in our 

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