Yige Sun, University of Oxford
Yige Sun, research associate at the University of Oxford, David Cockayne Junior Research Fellow at Linacre College, is investigating surface analysis techniques for lithium-ion batteries as part of the Nextrode project
Tell us about your research
I use a plasma focussed-ion beam and secondary-ion mass spectrometry to analyse the interfaces inside lithium-ion batteries (LIBs). Inside a LIB, there are many components (such as the aluminium current collector, cathode, separator, anode, copper current collector, electrolyte etc), and therefore, many interfaces in between. I investigate electrodes, and reactions that occur at these interfaces, and their impact on battery degradation. For example, the solid-electrolyte interface on the cathode side is less understood than on the anode side. This is because of a higher voltage range and more complex reactions but we are slowly learning more about it.
How do you describe why your work is important to non-specialists?
My microscopy work could allow us to uncover things that have alluded us for a long time. Over the last thirty years, the movement of lithium ions has been the main process by which our batteries have worked, but we do not understand how lithium ions move under different conditions, or how they impact battery degradation. We have a general idea of what might be happening and what influences the process, but we don’t understand the function of many interface reactions, and so we are unable to influence them to improve batteries. Research on the interfaces within a battery can uncover these mysteries.
How did you get into battery research?
My master’s course in Materials Science and Engineering at Tsinghua University in China included a module about interdisciplinary research, in which sustainable materials was one of the key lecture topics. After the course, I wanted to learn more and wondered what part I could play in positively impacting the environment, and I decided to explore battery research as a possibility. My master’s project was on cathode materials. I then did a PhD in a combined programme run by the National Institute for Materials Science and the University of Tsukuba in Japan, where I worked on the anode side of a battery. I worked on entirely different materials than I did for my research on the cathode, including graphene and carbon nanotubes, molybdenum disulfide (MoS2), and expanded beyond lithium-ion batteries to work on supercapacitors, sodium batteries, and lithium-ion capacitors. This period helped me to build a good foundation in electrochemistry and broaden my vision. I then started a postdoc at the University of Oxford, where I currently work.
What is a highlight of your career to date or the aspect that gives you greatest job satisfaction?
Problem-solving and continuing to learn gives me the greatest job satisfaction, though there are many publications and patents that I am very proud. I have to say that I most enjoy solving problems and those moments when I get to tell myself ‘ha, I am smart!’ are so joyous and satisfying. I enjoy taking videos of these mini success moments and sharing them with (showing them off to) my colleagues. Of course the joy I feel after solving a problem is directly proportional to how long I’ve had to suffer with it!
I love being a continuous learner. Since 2020, I have been involved in a student robotics programme, the Oxford Robotics and Additive Manufacturing Society as a project leader. As a result, I have learned three different coding languages in the last three years and use them to control and design robots. Continuing to learn gives me great satisfaction and keeps my mind sharp!
What accomplishments are you most proud of?
I am proud that I can see a big difference in myself during my journey. I feel both like I am my best friend, and also that I am able to observe my growth and development as though from the outside. There are still things that puzzle me. I am growing every year and am still learning.
On a slightly different note, I joined a Career Support Network mentoring programme under the at Oxford University. I started to think about how to use what I have learnt to boost the community, and have gotten involved in helping a younger generation of researchers and students find their self-awareness and be more affirmative in their careers. I’m learning alongside the experience, and it’s a fulfilling journey.
What opportunities has being part of the Faraday Institution opened up for you?
Last year I joined the EMPOWER women programme, organised by the Faraday Institution and delivered by Skills4, which has been excellent. It is so encouraging to see so many female researchers from different backgrounds, career stages and universities. We shared knowledge and experiences and coached each other to be more confident and proactive. We’re a very supportive group, and there has been an ongoing community beyond the programme, which is something so beautiful that is often easily neglected.
The Faraday Institution has created a highly collaborative environment, which is essential for battery research. We communicate frequently with researchers from various universities and with different capabilities.
What are the biggest challenges you have overcome in your career and how have you gone about doing so?
My biggest challenge is finding professional branding for myself. I’m not sure if it will come to me suddenly or be a long-term journey, and I’m still trying to figure it out.
What are your career aspirations?
I would like to be someone with great engagement in the community and the ability to impact the next generation of researchers and the community. This is my main goal for the next five years. With this in mind I joined a science outreach engagement activity, ‘I am a scientist get me out of here’, which connects scientists with students aged 10 to 18 through text-based chats. I recently joined the earlier career researcher (ECR) committee that is organising the ECR conference on the 31st of October in Warwick. The conference is designed by us ECRs to support the development of each other, improve networking skills, and boost the community.
What advice would you have liked to have given your younger self starting out on your career?
I would tell myself to try more new things, but with a rational consideration! For young people, it’s easy to grab every opportunity without much thinking behind those choices, or say no to any new opportunities. It’s important to try things, but also to try different things and explore options with due consideration, rather than grab at any opportunity just because it is there.
If people want to find out more about your research, where would you point them to?
Published October 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.