Material handling at the basic level, WITH ONEJu Li demonstrates new properties for energy applications.
For much of his career, Ju Li advanced in the theoretical aspects of his work, which investigated the fact that manipulating and restructuring materials on an atomic scale could create surprising and useful new macroscale properties. This research, which began in 1994 as a graduate student at MIT, was located at the “interface between the known and the unknown,” says Li PhD ’00, professor and professor at the Battelle Energy Alliance Nuclear Science and Engineering (NSE). Materials Science and Engineering. “It was very appealing to me. There was a kind of uncertainty in doing the research that was almost addictive.”
Li said that the position of the atoms modeled “a way to track the trajectories of Newton’s planets,” was a profound game: “Science was fascinating, and I had a lot of fun doing simulations of electrons, atoms, and defects,” he says.
But starting in 2011, after returning to MIT as a teacher, Li began to question his goals. “As one gets older, doing theory and talking about science is not enough,” he says. “I knew from the late 90’s that climate change was an issue, and I realized that I personally could do a lot and have to do it to make contributions.”
Li acknowledged that the microstructure simulations of his years provided a solid platform for exploring energy solutions to address climate change. He launched an experimental program in his lab, which, he says, “focused on engineering.”
The result: an abundance of advances in materials made with nuclear energy, batteries, and energy conversion applications that have important implications in the short and long term for decarbonizing the planet. The breadth of work covered in hundreds of articles in the journal – 45 in 2020 alone – has earned Li recognition, including the Material Research Society, the American Physical Society and the election last November as a member of the American Association. For the Advancement of Science.
What drives all this productivity is “feeling the pressure of time,” says Li, who has launched an ambitious campaign “basically to help save the Earth”.
Investigating A + B
As a way to organize an energy research portfolio and establish a model for a larger research community, Li has raised two “A + B” sections:
“‘ A ’is for action, which means that with rapidly increasing proven technologies such as nuclear power and battery power storage, we know they can operate on the terawatt scale needed to reduce CO.2 spills before the huge half-century, ”says Li.“ ‘B’ is for baby technologies, like advanced fission and fusion reactors, and quantum computing, so that the new technologies we need to feed today are ready in 20 to 30 years’ time. “
Li believes that the earth is on fire, and it is important to direct the full force of scalable technologies to the conflict right now. “You put out the fire by 2050, slowing down the CO slope2 and raising the temperature, then scaling cleaner, more advanced energy systems, ”he says.
To underscore its commitment to this approach, Li launched the Applied Energy Conference last year: MIT A + B demonstrates the most promising materials and technologies for immediate and future energy impacts.
Li’s A + B research has in-depth knowledge of materials theory, modeling, and microstructure science. He has been researching innovative applications for elastic stress engineering for more than a decade, creating new techniques, optical, electrical, thermal, catalytic, that put tremendous traction and mechanical shear in a similar atomic structure of a network of certain materials. and other properties. This approach first emerged in the 1990s when researchers filtered 1 percent of silicon crystal grids beyond their original state, allowing electrons to travel faster through the material and setting the stage for laser and transistor enhancements.
Li’s group has exceeded the limits of previous elastic stresses, releasing greater potential in materials. Among other achievements, his team can filter silicon beyond 10 percent and diamond beyond 7 percent, paving the way for much faster semiconductors. They have developed better catalysts for hydrogen fuel cells and for the energy conversions needed to convert electricity from solar, wind and nuclear into a chemical fuel that can be stored. Li’s team has also demonstrated superconductors with deformation engineering. “These metal voltage conductors can significantly improve superconducting magnets, as well as efficient long-range power transmission,” he says.
Nanocircuit and beyond
In another application of stress engineering, Li and his assistants were able to stretch micron-sized and uniformly shaped structures from industrial diamond material by expanding microfabricated clamps caused by microelectromechanical systems. These structures, which Li calls microbes, have unique electrical properties and can be massively repeated. “We can put the gills of these microbes in the waves, and each of those bridges can take on thousands of transistors,” Li says. “We hope that photovoltaic solar power can be useful in electronics.”
This nanocircuit work is part of Li’s extensive efforts in advanced computing, which encompasses a wide range of engineering techniques. For example, his laboratory has learned to manipulate simple atoms with great precision, using very careful electron beams. “We can drip and shoot atom, like soccer balls, controls its direction and energy, “says Li. It is a study that hopes to advance quantum information processing, driving many areas of engineering including A + B technology.
In parallel with this advanced work in computing, Li is making progress with critical energy applications, aided by in-situ transmission electron microscopy, machine learning, and electronic structure modeling. A current project: to design safe and powerful batteries in all solid states, using honeycombs -form-shaped nanostructures that are stable in contact with high-corrosion lithium metal.
In the field of nuclear power, Li strengthens strong metal nanocomposites, carbon nanotubes and nanowires that can withstand high-dose radiation and high temperatures. 3D printing of refractory alloys; and materials made of ceramic zirconium crystals, which can serve as thermal insulators, taking heat up to 1,400 degrees. Celsius. It is also undergoing processes to remove radioactive gases and liquids from treated spent fuel, in an attempt to “completely close the nuclear fuel cycle,” Li says.
To end this flood of research, Li is leading the Center for Low-Energy Energy for Materials and Extreme Environmental Materials with the MIT Energy Initiative, NSE Professor Bilge Yildiz.
From theory to device
As the son of two engineers who built nuclear power plants in China, Li always felt comfortable with nuclear power and other sophisticated energy technologies. But he loved computer programming and theoretical physics, and he never saw himself as an engineer.
Through MIT tutor emeritus Sidney Yip, who expanded the fields of materials science and nuclear science, Li first recognized the almost unlimited potential of working with materials. “That completely shaped me as a scientist,” he says. “I knew both how ignorant I was and what interdisciplinary research could be.”
After nine years of “learning the ropes” at other universities at MIT, Li had the tools at hand, and a new resolution to begin “providing increasingly important material solutions to the problems of climate change”. “Going from computer simulations to real devices is what I like to do now.”
With three children, Li is increasingly concerned about the need for his role. “I’d love to see some of my discoveries and inventions replicate exponentially, people actually use them,” he says. “My dream is to see carbon-free and improved lives around the world.”