Using a low-cost chemical process, researchers have turned waste glass bottles into nano-silicon anodes for lithium-ion batteries.
Even with today's recycling programmes, billions of glass bottles end up in landfills every year. A team of researchers at the University of California, Riverside's Bourns College of Engineering has found a new use for waste glass—batteries.
Using a low-cost chemical process and waste glass bottles, the team created nanosilicon anodes for high-performance lithium-ion batteries that can be used to extend the range of electric vehicles and plug-in hybrid vehicles, as well as provide more power with fewer charges to personal electronics like cell phones and laptops.
Silicon anodes can store up to 10 times more energy than conventional graphite anodes, but expansion and shrinkage during charge and discharge make them unstable. Downsizing silicon to the nanoscale has been shown to reduce this problem, and by combining an abundant and relatively pure form of silicon dioxide and a low-cost chemical reaction, the researchers created lithium-ion half-cell batteries that store almost four times more energy than conventional graphite anodes.
Figure 1: Waste glass bottles are turned into nanosilicon anodes using a low cost chemical process. (Source: UCR)
To create the anodes, the team used a three-step process that involved crushing and grinding the glass bottles into a fine white power, a magnesiothermic reduction to transform the silicon dioxide into nanostructured silicon, and coating the silicon nanoparticles with carbon to improve their stability and energy storage properties.
Coin cell batteries made using the glass bottle-based silicon anodes greatly outperformed traditional batteries in laboratory tests, researchers said. Carbon-coated glass derived-silicon (gSi@C) electrodes demonstrated excellent electrochemical performance with a capacity of ~1420 mAh/g at C/2 rate after 400 cycles.
Changling Li, a graduate student in materials science and engineering and lead author on the paper, said one glass bottle provides enough nanosilicon for hundreds of coin cell batteries or three-five pouch cell batteries.
“We started with a waste product that was headed for the landfill and created batteries that stored more energy, charged faster, and were more stable than commercial coin cell batteries. Hence, we have very promising candidates for next-generation lithium-ion batteries,” Li said.
Published in the Nature journal* Scientific Reports*, the research, "Silicon derived from glass bottles as anode materials for lithium ion full cell batteries," is the latest in a series of projects led by Cengiz Ozkan, professor of mechanical engineering, and Mihri Ozkan, professor of electrical engineering, to create lithium-ion battery anodes from environmentally-friendly materials. Previous research has focused on developing and testing anodes from portabella mushrooms, sand and diatomaceous (fossil-rich) earth.