This produces structures with good conductivity at room temperature while still preventing dendrite growth. To screen out dendrites, the nanoparticle-tethered PEO is cross-linked with another polymer, polypropylene oxide, to yield mechanically robust membranes that are easily infiltrated with liquid electrolytes. The idea was to take advantage of “hairy” nanoparticles, created by grafting polyethylene oxide onto silica to form nanoscale organic hybrid materials (NOHMs), materials Archer and his colleagues have been studying for several years, to create nanoporous membranes. You don’t, of course, but with the technology that the Archer group has put forth, creating a highly efficient lithium metal battery for a cellphone or other device could be reality in the not-too-distant future.Īrcher credits Choudhury with identifying the polymer polyethylene oxide as particularly promising. “And the obvious challenge that brings is, how do I put that in my iPhone?” “This means that batteries that use ceramics must be operated at very high temperatures – 300 to 400 degrees Celsius, in some cases,” Archer said. Friend Family Distinguished Professor of Engineering and director of the Robert Frederick Smith School of Chemical and Biomolecular Engineering. “The problem with ceramics is that this brute-force solution compromises conductivity,” said Archer, the William C. The relative non-conductivity and brittleness of such barriers, however, means the battery must be operated at high temperature and are prone to failure when the barrier cracks.īut a Cornell team, led by chemical and biomolecular engineering professor Lynden Archer and graduate student Snehashis Choudhury, proposed in a recent study that by designing nanostructured membranes with pore dimensions below a critical value, it is possible to stop growth of dendrites in lithium batteries at room temperature. Over many hours of operation, these dendrites grow to span the space between the negative and positive electrode, causing short-circuiting and a potential safety hazard.Ĭurrent technology focuses on managing these dendrites by putting up a mechanically strong barrier, normally a ceramic separator, between the negative and the positive electrodes to restrict the movement of the dendrite. But these batteries are not in common use today because, when recharged, they spontaneously grow treelike bumps called dendrites on the surface of the negative electrode. Rechargeable lithium metal batteries have been known for four decades to offer energy storage capabilities far superior to today’s workhorse lithium-ion technology that powers our smartphones and laptops. Friend Family Distinguished Professor of Engineering and director of the Robert Frederick Smith School of Chemical and Biomolecular Engineering, in a classroom with graduate students Akanksha Agrawal, left, Rahul Mangal and Snehashis Choudhury. Learn about the developing brain and how your brain changes throughout your lifetime with this comprehensive website.Lynden Archer, second from left, the William C. Decades of imaging work have led to remarkable insight and a more than a few surprises.Įducator Resource: The Secret Life of the Brain Why do teenagers seem so much more impulsive and so much less self-aware than grown-ups? Hear neuroscientist Sarah-Jayne Blakemore explain in this TED talk.įor more than twenty years, National Institute of Mental Health neuroscientist Jay Giedd has studied the development of the adolescent brain. ![]() Sarah-Jayne Blakemore: The Mysterious Workings of the Adolescent Brain Having a bigger brain does not guarantee more cognitive power. Myth: The Bigger the Brain, the Smarter You Are But what if something in early life interferes with the ability to take in sensory information? Research shows early childhood is marked by critical periods - times when the brain is intensely adaptable to new sights, sounds, tastes, and touches.
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