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Complex metal Bismuth may be the future of clean energy

Bismuth is a heavy, brittle metal that forms colourful geometric crystals when melted down. Completely nontoxic and able to absorb light almost anywhere, it may one day power our homes with clean energy.

Looking like an artifact straight from a Guardians of the Galaxy movie, Bismuth, or Bismuth Subsalicylate is an iridescent metal which could replace conventional batteries for good in the near future.

Bismuth has been a known metal since ancient times, though it was often confused with lead and tin as they share similar properties. It’s when the brittle mineral is melted down and cooled into alien-like form that its potential value comes to light.

First identified as a mineral in 1753, it was typically mined along with lead, tin, and copper for use in things like cosmetics and paint. But unlike the metals surrounding it on the periodic table, modern science has deemed it benign for human consumption and non-toxic to our environment.

If you head into your medicine cabinet and grab the bright pink anti-diarrheal drug Pepto Bismol, you’ll see each bottle has as much as a quarter gram of Bismuth in it.

File:Wismut Kristall und 1cm3 Wuerfel.jpg
Credit: Wikipedia

Having spent decades in circulation throughout the pharmaceutical industry, scientists have long theorised that Bismuth could be the sustainable successor to lithium and silicon batteries that we’ve long been searching for.

But in what ways does Bismuth differ to conventional batteries?

According to scientists like Robert Haye, of the Imperial College London, Bismuth-based semi-conductors have been found very effective in converting light sources into energy – making it a ‘photovoltaic’ material, for those into physics.

Unlike most photovoltaics, however, Bismuth also has unique electronic properties that make it effective for indoor use and places the sun struggles to reach directly. While traditional photovoltaic cells rely heavily on infrared light, the Bismuth ones have a wider band gap allowing them to absorb more invisible light.

Not to mention it boasts some of the lowest thermal conductivity values in metal. Anyone who runs high spec games on a laptop will more than appreciate that aspect.

Coined by those in the know as the ‘Green Element,’ Bismuth is beginning to replace lead in electric solder, fire sprinkler systems, and the lining of waterpipes in houses, reducing the risk of toxins spreading in our soil and water.

As the internet of things becomes more sophisticated in the modern home, Bismuth semi-conductors could have umpteen uses. Smart devices unconnected to a centralised system – like temperature sensors, lighting systems, and alarms – need powering somehow, and this nifty material might be the answer.

‘We’ve found that if you take Bismuth based compounds indoors, you can increase the overall efficiency by a factor of five,’ says Haye.

Theoretically, if Bismuth semi-conductors rolled out on a wide scale today, everyday batteries reliant on lithium, cadmium, and cobalt, would likely become redundant and fast. Imagine never having to replace a battery.

While the Earth’s crust isn’t exactly brimming with Bismuth to mine – it ranks 69th in the elemental abundance scale – there is enough in the world to ‘support the widespread deployment of Bismuth semi-conductors,’ as they require far less material than silicon based implements to generate energy.

As we approach 2023, around 15 billion household batteries have been thrown in landfill sites. So, the next time you drink a spoonful of Pepto Bismol, consider the possibility that the mineral you’ve just consumed may one day end our search for sustainable energy.


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