Spotlight on Professor Mino Green
Professor Green is the founder and developer of Nexeon’s basic technology and an Emeritus Professor at the Department of Electrical Engineering at Imperial College London.
Professor Green, you’ve spent time working in both academic research and in commercial industry. How have you found that your commercial experience has shaped your approach to research?
My years at MIT-Lincoln Lab and Zenith Radio Corporation have indeed shaped my approach to research. I love solving problems, but I also love presenting myself with problems by asking if there is an application for my work. And whether it is knowledge driven or device driven, the notion of “producing the goods” has always been important to me.
Which achievement are you most proud of in your commercial or academic career?
Pioneering the theory of the Semiconductor–Electrolyte interface where I showed that reversible electrochemical reactions were independent of the Fermi level. But on the other hand electron concentration was important for reaction rate – e.g. hydrogen over potential – and I showed that surface states were vital to the structure of the Sc-El interface and hence, inter alia, the double layer capacity.
What inspired the approach to structuring NEX-1 silicon?
I was listening to a lecture by Besenhard (1999-in Cetraro, S.Italy). He showed how much better silicon was than graphite as anode material, and then went on to say that unfortunately the large volume expansion that this involved (for silicon) was an obstacle to its use. I thought that silicon in sub-micron diameter pillar structure might get over that difficulty. And so it has proved.
What was the biggest challenge that you had to overcome in development?
Development has been and is a series of steps of variable difficulty, but we haven’t come across a very large obstacle yet. That is not to say that it has been easy! But our challenge has always been to stay within a particular cost model.
How is Nexeon’s technology different to other approaches currently being developed?
We have made use of structured silicon so that we have a sufficient plurality of electrical inter-connections to overcome the formation of electrically isolated regions resulting from cyclic expansion/contraction associated with lithium insertion/extraction.
What do you find most exciting about Nexeon’s technology?
The prospect for increased energy-density batteries for a wide range of applications, from credit-card size batteries, through medical applications to mobile ‘phones/lap-tops and the like, and onto cars.
Where do you see the future of batteries leading?
Batteries power portable electrical devices. The applications are limitless. The future is battery-powered.
What do you most enjoy about the process of commercialising technology?
The joy in succeeding at an incredibly difficult task.