The illumionONE represents a new category of operando analytical tool, designed and optimised for battery materials analysis. An optical microscope is a general-purpose tool, not specifically optimised for battery materials analysis.

illumionONE is similar to an optical microscope in that it captures images using a camera but differs in that it is a fully integrated system. It contains an integrated, high specification potentiostat, an automated focus-tracking system, and runs in-house developed software, optimised to simplify acquisition and analysis workflows.

illumionONE measures changes in scattered light intensity correlated with ion movement and phase changes and hence lets you observe what is happening inside particles within an anode or cathode during battery operation. These measurements are synchronised with electrochemistry data (captured using the system’s potentiostat); hence users can easily correlate observed changes in light scattering with specific electrochemical events. 

The illumionONE is ideal for real-time, in-situ analysis of battery processes and is perfect for users wishing to understand fast ion dynamics and battery degradation.

The measurement length will depend upon the charge-discharge protocol that the user defines (e.g., C-rate, number of cycles, etc.). The technique itself is capable of seeing events that occur on a very short timescale (sub-second). 

For battery materials scientists, charge photometry provides a missing link in the characterisation toolkit, complementing techniques like XRD (for crystallographic information), SEM (for high-resolution morphology), EIS (for interfacial processes), and Raman spectroscopy, with critical spatially resolved, time-dependent
information during actual battery operation.

Techniques like XRD and bulk electrochemistry give us averaged data across large numbers of particles. However, in battery electrode materials:

a. Not all particles charge/discharge at the same rate

b. Some particles degrade faster than others

c. Within individual active particles, ion insertion and removal may not occur
uniformly from all surfaces

Without single particle resolution, these heterogeneities would remain invisible.

When batteries fail, traditional measurements might tell you capacity has faded or that impedance has increased but they rarely reveal why. With charge photometry you can directly observe which particles crack first during cycling, identify particles that are inactive or lagging behind the electrochemistry and can watch phase transitions in real-time at the single particle level. 

Charge photometry simultaneously tracks particle state-of-charge and particle morphology changes while batteries undergo active cycling. This means that users can see transient phenomena that ex situ techniques would be unable to detect as well as establish a direct correlation between electrochemical state and structural evolution during cycling. These insights connect material properties directly to electrode performance and failure mechanisms. 

Charge photometry can be used with different battery chemistries and has already
provided new insights for a broad range of electrode materials. For example, if you visit our Cathode Materials Discovery Examples and scroll down, you will find data showcasing the use of the illumionONE charge photometry system for the study of a sodium-ion battery cathode.

During charging, particles of the NFM cathode material undergo a phase transition and its point of origin as well as progression through a particle can be tracked using charge photometry.

More technically speaking, charge photometry is sensitive to the electronic
properties of a battery material. When the battery operates, ions move in or out of the material, which is compensated by changes in the electronic structure of the material to enable charge storage. This connection results in a chemistry-agnostic contrast mechanism applicable to all battery chemistries. 

This is something the user does not need to worry about as illumion supplies
optically accessible charge photometry coin cells specifically designed for the
illumionONE. If you are already familiar with coin cell assembly, putting together an illumionONE coin cell is very similar.

With each illumionONE system purchase, a ‘Charge photometry (CP) coin cell
starter kit’ would also be purchased and this includes 25 ready-to-be-assembled
coin cells. Thereafter, a ‘CP coin cell consumables package’ can be purchased and this includes 50 ready-to-be-assembled coin cells. 

6 mm (diameter).

The illumionONE is designed to be a robust and easy-to-use system, suitable for any battery materials R&D laboratory. It is a compact system (40 (w) x 50 (d) x 31.5 (h) cm) and is supplied with an active vibration isolation system of similar footprint in addition to an acquisition PC with monitor and peripherals.

The FOV is 112 x 70 μm. The integrated motorised XY stage means that you can move to and image different areas of the electrode.

The illumionONE is supplied with an integrated potentiostat (potential range: ±6V;
current range: 100nA – 100mA; maximum current: ±200mA; current resolution:
9.2pA on 100nA range; voltage resolution: 183μV). If you have any questions
relating to the potentiostat, please do not hesitate to contact us directly
(info@illumion.io). We currently do not offer support for other potentiostats. 

Currently, we use a coin cell format with the illumionONE and there are a number
of reasons for this:

1. Operando imaging techniques often require custom specialised sample
   cells that can be difficult and time-consuming to assemble and use. The
   illumionONE was designed with ease-of-use and simplicity in mind, hence
   we have adopted a coin cell format. This is a format that can be easily and reproducibly assembled ensuring that charge photometry measurements
   can be learned very quickly by new users.
2. The illumionONE is mainly used for battery electrode materials discovery and optimisation, hence if a user is wanting to compare lots of different material compositions/formulations, it is important to ensure that any differences that are observed are due to the material itself and not
   introduced by the sample cell format. A coin cell sample format is therefore
   useful.

The illumion team are nevertheless looking to develop new sample cell formats.

To enable optical visualisation, the electrode under study needs to face the optical
window, which requires minor sample modification.

The illumion team has developed several methods to enable all electrode types to be effectively measured.

If you have any questions, please do not hesitate to contact us directly (info@illumion.io).