Environment

How recycled glass bottles can become better batteries

Researchers at UCR have found a way to make better batteries using discarded glass bottles
Researchers at UCR have found a way to make better batteries using discarded glass bottles
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The UCR team behind the bottle-based silicon anodes
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The UCR team behind the bottle-based silicon anodes
Glass bottles can be a good source of silicon dioxide, which can be crushed into nanoparticles and used to make anodes for coin cell batteries
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Glass bottles can be a good source of silicon dioxide, which can be crushed into nanoparticles and used to make anodes for coin cell batteries
Researchers at UCR have found a way to make better batteries using discarded glass bottles
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Researchers at UCR have found a way to make better batteries using discarded glass bottles

Ask a regular smartphone user how they'd like to see the devices improved, and it's a safe bet that longer battery life would be close to the top of the list. Batteries made with silicon anodes could help boost that, and now a team at the University of California Riverside (UCR) has shown that these batteries can be environmentally friendly too, by being sourced from glass bottles headed for the scrap heap.

Lithium-ion batteries power everything from smartphones to electric vehicles, and conventionally they're made with a lithium cathode and a graphite anode. But as useful as this setup has been over the years, the ceiling on their efficiency has all but been reached, prompting researchers to look to our old friend silicon as an alternative anode.

While they have the potential to store up to 10 times more energy than graphite, silicon anodes aren't quite as durable, with the expansion and contraction that comes with regular use cracking the material and wearing them down much faster. Past work has found that crushing the silicon first helped to overcome that problem.

Glass bottles can be a good source of silicon dioxide, which can be crushed into nanoparticles and used to make anodes for coin cell batteries
Glass bottles can be a good source of silicon dioxide, which can be crushed into nanoparticles and used to make anodes for coin cell batteries

With durability addressed, the UCR team's research has now found a new source of silicon for producing batteries: discarded glass bottles. The researchers aren't strangers to using unusual materials as anodes: in the past, they've dabbled in recipes using sand and mushrooms. Now they've shown that silicon dioxide can be wrung out of glass bottles, saving them from the fate of clogging up landfills.

First, the bottles are crushed and ground down into a fine, white powder. Next, the silicon dioxide is reduced down into nanostructured silicon with the help of hot magnesium, and finally, those nanoparticles are coated in carbon, which makes them more stable and improves their energy storage capacity.

When tested in coin cell batteries over 400 cycles, the bottle-based silicon anodes demonstrated a capacity of about 1,420 mAh/g (milliamp hours per gram), a huge improvement over the storage capabilities of graphite anodes, which typically manage about 350 mAh/g.

"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," says Changling Li, lead author on the study. "Hence, we have very promising candidates for next-generation lithium-ion batteries."

The researchers say that the process is viable, thanks to the low-cost chemical reaction and the fact that each glass bottle can create enough nanosilicon to make hundreds of coin cell batteries. The team has filed a patent to commercialize the process and products.

The study was published in the journal Scientific Reports, and the process is outlined in the video below.

Source: University of California, Riverside

The Glass is Greener

5 comments
BarwiseBirch
My God, are the USA still sending glass bottles to dumps. We recycle them and have been doing so for years!
Bob Stuart
People almost always want better battery life. What I don't understand is why we so seldom see a device smaller than its battery. Even simple flashlights try to make their batteries a minor component, but at least those can be swapped for spares.
Mzungu_Mkubwa
@BarwiseBirch Most towns have recycling programs in the U.S., but wouldn't even be able to guess at the percentage of glass re-used. However, this is far from the most significant aspect of this research - I'd say merely a PC/PR stunt. To have quadrupled the energy density of li-ion batteries is huge, immediately erasing the primary objection to using electric to power vehicles: range anxiety. If the phrase "durability addressed" is actually true (how many cycles have been tested and what degradation levels have been observed?) then these dudes have a very valuable patent on their hands.
Nik
A battery like this would keep my watch operating for years, and year, and years....cant be bad! In the UK, bottles are recycled as hardcore, for building fill, not wasted as land fill. Recycling glass for glass is not cost effective, as it costs more to ship empty bottles than the bulk sand they are made from.
Karmudjun
Actually, we in the U.S.A. have been recycling, re-purposing, and reusing glass bottles for decades. We have also been throwing them with notes into the ocean and breaking them over people's heads in the movies. And some communities without full service recycling still provide glass recycling. BarwiseBirch, please let your God know?
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