Alice Merryweather, University of Cambridge
Alice Merryweather, PhD Researcher, University of Cambridge, developing an innovative optical microscopy technique to see inside batteries
Tell us about your research
I’m a third-year PhD researcher at the University of Cambridge working on the Faraday Institution’s battery degradation and characterisation projects. I’m developing a new method for studying battery materials that uses an optical microscopy technique called interferometric scattering microscopy. This method gives us access to length and timescales that would be very hard to measure using conventional battery characterisation techniques. It works by illuminating a working battery with an LED and collecting the light that is reflected and scattered. When the battery is cycled, and lithium ions are added or removed from the active battery material, the optical properties of the material change. These changes can be rapidly detected with our new technique, allowing us to map changes in lithium content in the electrode in real time. We’re observing the electrode on a micron scale, which provides different and complementary insights to ensemble characterisation techniques where the data collected is an average from the whole electrode, and to small field of view techniques like transmission electron microscopy.
How do you describe why your work is important to non-specialists?
This technique allows us to see what limits the transport of ions in a battery, which will affect the battery’s capability to rapidly charge and discharge. For example, in the materials we’ve looked at so far, we’ve been able to identify what transport processes are rate-limiting at different points of the charge / discharge cycle. We have observed degradation mechanisms, such as individual particles fracturing during cycling, which is one mechanism thought to lead to capacity fade (the gradual loss of a battery’s ability to hold charge). With this information we can better design the materials that go into batteries to help them perform better, and also optimise cycling protocols.
How did you get into battery research?
Sort of accidentally! I have always been interested in both physics and chemistry, so I did half and half as an undergraduate at the University of Durham. And that’s kind of what I’m still doing! I now have a supervisor in the Chemistry Department, Professor Dame Clare Grey, and a supervisor in the Physics Department, Professor Akshay Rao. In battery research there is a lot of cross-over between physics and chemistry.
What is a highlight of your career to date or the aspect that gives you greatest job satisfaction?
I have really enjoyed working in two different research groups with different areas of expertise. When this project began, Akshay’s group didn’t know much about batteries, whereas Clare’s group knew loads about batteries but had little to do with optics! I have been able to learn about and help to bring together two areas of science and two different research communities, which has been very rewarding. Multi-disciplinary collaboration is so key to advancing battery research.
What accomplishments are you most proud of?
It’s exciting that people get excited about this technique! I’m looking forward to seeing if the new technique continues to be used by other researchers and where it will take off. If it does, that would be an amazing accomplishment.
What opportunities has being part of the Faraday Institution opened up for you?
Getting a perspective of all the battery research going on the UK, through conferences and discussion, even during lockdown, has been very rewarding. These conferences have fostered new contacts and connections.
I work closely with Dr Christoph Schnedermann, who has been awarded a Faraday Institution Entrepreneurial Fellowship for an exciting new spin-out which aims to commercialise the optical microscopy technique. I have been involved in getting the spin-out rolling and doing initial cell development.
What are the biggest challenges you have overcome in your career and how have you gone about doing so?
It has sometimes been challenging having a project which is very different to what most people in both research groups are working on. Generally speaking, battery people don’t often think in terms of optics and optics people don’t often have expertise in batteries. Drawing those viewpoints together and translating between them to get something that works is a broad challenge I have had throughout my PhD. I have navigated this by working closely with my brilliant colleagues from both groups and taking extra care to make sure there is a shared understanding of what we mean when we use certain terms. Sometimes this means taking a step back and bringing things back to basics.
What advice would you have liked to have given your younger self starting out on your career?
Ask more questions!
I started a PhD within two large research groups, each with lots of researchers with wildly different projects, and trying to understand it all was initially overwhelming. Asking more questions earlier would have given me a wider context and allowed me to better engage with the variety of problems and research that people are working on.
If people want to find out more about your research, where would you point them to?
They should watch my presentation from the Early Career Researcher day of the Faraday Institution conference in 2021, for which I won the Communication and Audience Engagement award.
Connect with Alice on Twitter and LinkedIn
Published August 2022.
About the author: Cara Burke is the Faraday Institution’s Science Communications Intern in the summer of 2022. She has just completed her BSc Biological Sciences degree at Imperial College London and is pursuing a career in science communications.