Ruihe is doing his PhD in the Electrochemical Science and Engineering (ESE) group.

"I appreciate every second of working in the office and lab to create something new and answer some interesting scientific questions."

When did you decide to do a PhD and why?

The most important reason is that I am eager to create something new to the world. I realized this when I chose the subject of my undergraduate after the college entrance exam. My family wanted me to choose finance-related subjects because that allows me to earn more money in the future. However, from the bottom of my heart, what I really want to do is to create something new to the world. This is especially important if I consider that we are all mortal and will die someday. My creation- either a machine, or a theory, or even just a new equation that supplements to a bigger theoretical framework- will be the important evidence that I have ever existed.

The second reason comes from an evaluation of me given by my most important teacher in high school. She told me, “Ruihe, you are smart. You are good at learning and using knowledge. You should take full advantage of this.”

Finally, my short working experience in a company has confirmed that my ideal life is to carry out solid research as a scientist. I worked in a start-up company for 5 months. The working environment in this company is super fast-paced. Everyone was required to carry out work quickly, without understanding the underlining science. Then I realised that if I wanted to continue my work on the premise of understanding everything, the only way will be to go in academia. To get there, I need to get my PhD first.

How has your experience been so far, and what do you enjoy the most about it?

The whole journey has been really amazing! This is not just about me; it is about my whole family. My daughter was born several months before I started my PhD, which was a delight but also a challenge. I already had a confirmed PhD position in Imperial, but my wife did not. We wanted to make sure we could live together and raise our daughter together, even in a country that we had never been to. In the end, we made a bold decision that she would start at Imperial as a visiting researcher for 6 months without pay and would look for post-doc position later, which meant that we went through financial difficulties during this period.

This journey started from May 2021, when I arrived the UK first. In September 2021, my wife brought my daughter to London when my daughter was just 8 months. We sent her to the Imperial Early Years centre during daytime, then picked her up in the afternoon. Both my wife and I had limited working hours, as taking care of a young child consumes lots of time and energy. But that just forced us to be more efficient.

Luckily, everything has went on smoothly. My wife got a post-doc position after 6 months. We both got some nice work done and submitted one or two papers. Our daughter has been a very happy girl. To sum up, the most enjoyable part of my PhD is to grow together with loved ones.

What is your PhD research about?

My PhD research is about prolonging the lifetime of lithium-ion batteries by investigating how the liquid inside them is consumed. The ions inside the lithium-ion batteries must move through some liquids, which is called electrolyte. The electrolyte in lithium-ion batteries contains salts and solvents. During charge, discharge, or even storage (do nothing), the solvents will be consumed gradually, mainly through a reaction called solid-electrolyte interface (SEI) reaction. However, most previous studies have only focused on the SEI itself, but not the consumption of solvent. During later stage of battery life, the solvents may be completely consumed, and the batteries will dry out, i.e., ions are unable to move anymore. Therefore, my PhD study investigates the underlining mechanisms of this solvent consumption process, and quantitatively evaluates its effect on battery lifetime.

What would you say about the supervision you receive?

I have three supervisors, my main supervisor is Professor Gregory Offer, secondary supervisor Dr Monica Marinescu, assistant supervisor Dr Simon O’Kane. They are all very intelligent and nice people. We have weekly meetings which normally last for 30 minutes to 1 hour. Greg and Simon will join every week. Monica joins less frequently because she has many other responsibilities but still will be at least once a month. Greg helps me to paint a big picture at the very beginning of my PhD and divides this into a series of well-organised small projects. Simon is very responsive and gives support on any day-to-day issues.

Apart from the help on research, they also provide a lot of support in my life. Greg and Monica have given useful advice on raising a young child. Simon has given me comprehensive suggestions on renting and many other issues. They are all very considerate about my special situation and willing to give me a hand whenever I need.

Do you have any thoughts about what you might like to do in the future?

I will seek a post-doc position or research fellowship and then a lecturer position. The ultimate idea is to become a scientist in a university and continue the research I love. I will stick to my initial drive and create something new and useful which makes a positive contribution to the world.

What advice would you offer to students considering applying for a PhD at Imperial?

Pursuing a PhD is not that difficult if you have a strong and clear motivation. Good supervisors are very important. Try your best to get to know them before you decide. It is very common that you will get stuck at some point, but just keep trying. Imperial is a wonderful place where many supporting resources are available, other than your own research group. It is also a platform which allows you to get in touch with the most intelligent people in this world. Don’t take these for granted and do make good use of all these resources.