Engineering news
Engineers at the University of California, Riverside are using a low-cost chemical process to turn waste glass bottles into silicon-nanoparticle anodes – the negatively charged side of batteries – for high-performance lithium-ion batteries.
"We started with a waste product and created batteries that stored more energy, charged faster, and were more stable than commercial coin cell batteries,” said Changling Li, materials engineer at the university and the lead author of the study. “We have very promising candidates for next-generation lithium-ion batteries.”
The silicon dioxide found in the billions of glass bottles that end up in landfill sites every year could replace graphite as a material for anodes, as silicon can store up to 10 times more energy, according to the researchers.
But the problem with silicon is its tendency to expand and shrink during charge and discharge, making it unstable.
The team overcame this issue by downsizing silicon to the nanoscale, putting an almost pure form of silicon dioxide through a chemical reaction to produce lithium-ion half-cell batteries that can store nearly four times more energy than conventional graphite anodes, said the scientists.
The Riverside researchers created the anodes for coin cell batteries by crushing and grinding bottles into fine white powder. They then turned silicon dioxide into nanosilicon by removing oxygen using magnesium at an elevated temperature. The nanoparticles were then coated with carbon to improve stability and energy storage properties.
One glass bottle produces enough nanosilicon to make hundreds of coin cell batteries or up to five pouch cell batteries, Li added.
The team has previously developed and tested lithium-ion battery anodes made from other environmentally-friendly materials such as
portabella mushrooms and
sand.
The study was published in
Nature’s journal
Scientific Reports.