5 minute read
Scientists are just people; throw us hungry on an uninspiring place and tell us to collaborate or innovate and nine out of ten times the results you get are less than stellar. Ah, but do the opposite, inspire us, feed us well, and watch networks and ideas blow-up in their own real-time “big bang.”
The International in-Operando Battery Days in France, which took place earlier this summer, was a perfect example of how to get the right balance between scientific rigor, rich culture, and breath-taking natural beauty. Two researchers that represented NPL in that conference can now fully attest to that fact, my colleague, Dr Rudra Samajdar, and myself, Dr Carmen M. López, both Senior Scientists and both working in the Electrochemistry Group.
Home to the European Synchrotron Research Facility (ESRF) and to legendarily delicious walnuts, Grenoble is a college city of close to 715,000 people nestled among dazzling alpine peaks in the Isere River valley. Grenoble is also the home of the International In-Operando Battery Days conference, organised by researchers from the French National Centre for Scientific Research (CNRS) and the French Alternative Energies and Atomic Energy Commission (CEA). The conference brings together approximately 120 participants from around the world for four days of talks, posters, and face-to-face scientific networking and debate. 
The conference in June was the first time I had participated. I had never been to Grenoble before, and though I knew some people from my long stretch in lithium-ion batteries (Li-ion) research, it was only during the last year at NPL that I had led the development of the technique that I was now going to unveil to the world in all its—I hoped—glory and magnificence. I had no doubt about the research, my coauthors and I had worked diligently and systematically on the method and had extensively corroborated our results. However, there was no telling how a community of mainly synchrotron and material scientists would react to our relatively simple experiments that involved commercial Li-ion cells and no beam time nor any high-energy radiation whatsoever. Will I be able to get my point across? Will my presentation be well-received? Or will I simply be ignored by the very people with whom I wished to network and collaborate?
Those thoughts ran in my head over and over as I watched the scenery on my way from the nearest airport, Lyon Saint-Exupéry, towards my hotel in the city centre of Grenoble. I knew that the in-operando battery community was a particularly friendly one from the comments of my colleague, Dr Rudra Samajdar, who had participated in the previous issue of the conference and had a very positive experience. But add together the facts of my new technique, the new crowd and myself just past two years from a career break that threatened to put me out of science altogether and I felt that I had a lot to prove.
Rudra, the only person that I knew well in this conference, was arriving at a different time and from a different place, so all by myself I had dinner at my hotel, reviewed my PowerPoint slides once more and went to sleep dreaming of how to avoid exploding batteries. Early next day, the conference began.
As expected, most of the presentations and posters where focused on materials characterisation using synchrotron-based techniques. A lot of the discussion was centred on sample beam damage from synchrotron radiation and how that affected, or not, the very measurements on which researchers reached important conclusions. There were spirited exchanges of ideas, but the environment was generally friendly and professional.
Dr Samajdar presented a poster entitled ‘Novel cell configurations for minimally invasive operando spectroscopy of batteries’ in which he demonstrated some of the recent initiatives from NPL in building a standardised measurement method for looking inside batteries while they are being used, with the aim of understanding what causes some batteries to last longer than others. This is work that NPL has been developing over the last two years in collaboration with other European national labs. Many of his collaborators were present at this conference and there were plenty of opportunities to brainstorm about future project directions. The poster session was held over drinks in the evening over the first two days of the conference. Among people who were interested in the poster were staff members from the CEA, the Basque research institute CIC EnergiGUNE, and several large-scale experimental centres from other European countries.
I presented a ten-minute talk titled 'Correlative Differential Analysis of Formation Cycles in Li-Ion Cells Using in-Operando Chromatic Confocal Microscopy,' which is a mouthful to say that lithium batteries contract and expand during cycling, a phenomenon that many researchers had likened to "breathing" because, in part, it is due to internal gas generation. Just as with people, the way that the individual cells of the battery breathe offers clues on their health and age as well as providing data that can improve their safety and durability. Moreover, my talk described a new method developed at NPL that allowed us to measure commercial Li-ion cells under real cycling conditions without perturbing the cells. Perturbing is changing the behaviour of a system by the method used to 
measure it. And it is really important not to perturb what you are measuring in order to get real results and avoid misinterpretation.
I was really proud of presenting our results in an amphitheatre full of brilliant minds; at 17:00, on Thursday, just a couple of hours before the conference dinner and to about a hundred pair of eyes exhausted from the previous days and not enough caffeine. Predictably, when the question-and-answer session started I didn't get any questions—that's bad, really bad—until one of the organisers took pity on me and asked me something. I don't remember exactly what it was, but I saw my opportunity then and there and, standing up facing the audience, I asked for two things: first, “how many people work with commercial cells, please show of hands.” I counted about 15 people in that big room, more than I had expected. The second thing I asked was for them to “ask me questions, challenge me”. It took them about 10 seconds to realise that I was serious in my request and what followed was close to 20 minutes of the most rewarding discussion I have had recently. It felt fantastic.
After the session was finished a couple of other scientists approached me to show me their results and continue the discussion over coffee. That is when I discovered that other researchers in Germany had the same idea. When an idea appears independently in different laboratories it signals that it is a good idea. Good. I admired their method, along the same line of thought but different from ours and realised, that we are slightly closer to publication. All in all it was a great discussion. It energised me to push forward with getting my analysis published and if they publish first I’ll cite them.
That evening, the conference dinner was a three-course meal worthy of a fine dining restaurant, where everything from the development of international standards to dancing the tango in Argentina was discussed. Families, hobbies and laboratory equipment were also items on the conversation menu. Naturally enough, the last talks on Friday morning were more sedate, though surprisingly well-attended for the last day of a conference. Overall, the setting provided an environment where thoughts, rigorous and logical, were good table companions to the whimsical side of simply being human.
I have a hypothesis for which I am still gathering data: collaborative success is directly proportional to the quality of the food served, and if this is a good sample, I might yet be proven right. But if I am not, at least the memory of walnut cake and snow-capped mountains will cheer me up. Here’s to science! Cheers!
02 Sep 2024