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A team of scientists discovered a class of materials that challenge conventions: they shrink when heated and expand under pressure – in shock with the fundamental laws of physics. The discovery has numerous practical applications, including making your old electric car new.
What expands when crushed, shrinks when heated and can transform the fundamental understanding of scientists about materials and restore the performance of old electric vehicle batteries?
This is not a puzzle – It is a new and remarkable class of materials discovered by Battery investigators at the University of Chicago’s Pritzker School of Molecular Engineering (Uchicago PME) in collaboration with guest scientists at the University of California (UCSD).
Throughout his research, which was presented in a published on Wednesday in the journal Nature, the team discovered materials that show properties of negative thermal expansion In metastable states, active oxygen.
In simpler terms, these researchers developed materials that seem challenge traditional expectations based on thermodynamicsexplains the.
Normally, stable materials They respond predictably to heatpressure or electricity. However, meta -stable states recently identified, These reactions are reversedbehaving exactly unlike conventional norms.
“When we warm the materials, there is no change in volume. When warm, the materials shrink instead of expanding,” he said Ying Shirley MengProfessor of Molecular Engineering at Uchicago PME.
“We think we can adjust the properties of these materials through Redox chemistry. This can lead to very interesting applications“Note the researcher and main author of the study.
“One of the objectives is to bring these materials of the investigation to the industrypossibly developing new batteries with higher specific energy“, it says Bao Qiuresearcher at UCSD and co-author of the study.
Beyond myriad of new technologies enabled by this discovery, the investigation represents a advance in pure science. For Meng, this is even more exciting. “This changes our understanding of fundamental science“, Afirma Meng.
Buildings, batteries and “crazy ideas”
By thinning the way these materials react to heat and other forms of energy, researchers can Create materials with zero thermal expansion. This could revolutionize areas such as construction.
“Zero thermal expansion materials are the dreamI would say, ”said the teacher Minghao Zhang, corresponding author From work. “Let us take all the buildings as an example. We do not want the materials that make up the different components to change in volume frequently.”
But Heat is just a form of energy. To test the way these materials react to the energy mechanicalthe investigators compressed us to gigapascal level – such a high level of pressure that it is usually reserved to discuss the tectonic plates activity.
Found what they call “negative compressibility“.
“Negative compressibility is just like negative thermal expansion,” said Zhang. “If we compress a particle of the material in all directions, we imagine that it will naturally shrink. But this material expands“.
Material adapted to resist heat or pressure could allow some “Crazy Ideas” previously theoreticalsays Minghao Zhang, who gives the example of structural batterieswhere the walls of an electric plane also function as battery componentshelping to create lighter and more efficient aircraft.
These new materials could keep the battery components safe from temperature and pressure changes recorded at different altitudes, making The sky ceases to be the limit For this new technology.
Old electric as new
As with heat and pressure, the reaction of meta -stable materials to electrochemical energy, The tension is also reversed.
“This is important not only as a scientific discovery, but also very Applicable to Battery Investigation“Zhang said.“ When we use the tension, we take the material back to its original state. We recovered the battery. ”
To understand metaestibility, Imagine a ball in a hill. The ball is unstable at the top of the hill. It will roll down. It is stable at the bottom of the hill. Won’t roll For top. The metaestable state is in the middlea ball near the top of the hill, but nestled in a hole.
This metaestable state It can be quite durable – Diamonds are a metastable form of graphite, for example. But energy is needed To push a metastable material out of your “hole” so you can return to your stable state.
“To make the materials go from a metastable state to a stable state, It is not necessary to always use thermal energy“Said Zhang.“ It is possible to use any type of energy to make the system return. ”
This points a way to recover electric vehicle batteries aged. After years on the road, an electric car that has traveled, for example, 600km with a load, will only travel 350 or 300 km before it needs to be connected to the current.
Using a Electrochemical Motorizer Force to “push the materials” to their stable states, the car would have the autonomy again I had when it was young.
“No need to send the battery back to the manufacturer or to any supplier. Just make this voltage activation“Said Zhang.“ Then your car will be a new car. Your battery will be a new battery“.
