The research could lead to commercial batteries with longer lifespans for computers, smartphones, appliances, cars and spacecraft.
Scientists have sought to use nanowires in batteries. Thousands of times thinner than a human hair, they are highly conductive and feature a large surface area for the storage and transfer of electrons. The filaments are fragile and fail to support repeated discharging and recharging, or cycling. In a typical lithium-ion battery, they expand and grow brittle, which leads to cracking.
UCI researchers have solved the problem by coating a gold nanowire in a manganese dioxide shell and encasing the assembly in an electrolyte made of a Plexiglas-like gel. The combination is reliable and resistant to failure.
The study leader, UCI doctoral candidate Mya Le Thai, cycled the testing electrode up to 200,000 times during three months without detecting any loss of capacity or power and without fracturing any nanowires. The findings were published in the American Chemical Society’s Energy Letters.
“Mya was playing around, and she coated this whole thing with a very thin gel layer and started to cycle it,” said senior author Reginald Penner, chair of UCI’s chemistry department. “She discovered that just by using this gel, she could cycle it hundreds of thousands of times without losing any capacity.”
“The coated electrode holds its shape much better, making it a more reliable option,” explained Thai. “This research proves that a nanowire-based battery electrode can have a long lifetime and that we can make these kinds of batteries a reality.”
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