Candle soot can power electric car batteries, research says

By @iamkarlatecson on
A man holds candles during a mass baptism ceremony at Matka Snt Mother of God monastery, 15 km (9 miles) outside the capital Skopje September 1, 2007. Several hundreds of Macedonians of all ages gathered for a mass baptism on Saturday. Reuters/Ognen Teofilovski

A new study reveals that carbon from candle soot could be used to power the kind of lithium ion battery in plug-in hybrid electric cars. Researchers from the Indian Institute of Technology in Hyderabad, India claim that their findings could open up possibilities for using carbon in more powerful batteries, which could drive down the costs of portable power.

Lithium ion batteries are used to power a wide range of devices, including smartphones, digital cameras, electric cars and even aircraft. The batteries produce current through two electrically charged materials suspended in a liquid. Carbon, while used as one of the materials in smaller batteries, is considered unsuitable for bigger and more powerful batteries because of its structure, which cannot produce the required current density.

In the new study, published in the journal Electrochimica Acta, the researchers found that because of the shape and configuration of the tiny carbon nanoparticles, the carbon in candle soot could be used in bigger batteries. The team also said that their research introduces a more scalable approach to making batteries because the soot could be produced quickly and easily. 

“If you put water droplet on candle soot it rolls off – that’s an observation that’s been made in the last few years. The material candle soot is made of, carbon, also has electric potential. So why not use it as an electrode? We looked into it and saw it also shows some exceptional electrochemical properties, so we decided to test it further,” said Dr Chandra Sharma, one of the study’s authors. 

Soot, which is made of carbon, is produced when a candle burns. For the study, the team observed the soot collected from the tip and middle of a candle flame and compared the size, shape and structure of the carbon. They found that the burning process formed nanoparticles of carbon that are 30 to 40 nanometers across. They also found that the soot recovered from the tip of a candle flame, which burned at 1,400 degrees Celcius, had fewer impurities like wax, making it perform better as an electrical conductor.

Using a technique called cyclic charge-discharge, or CCD, the researchers analysed the effectiveness of soot as a conducting material to use in a battery. The technique shows how powerful the battery is based on the rate of charge or discharge: the higher the rate, the more powerful the battery. According to the study’s results, the candle soot carbon performed better at higher rates.

Sharma said the technology is not only efficient and cost-effective but also scalable, which could make battery production cheaper. One hybrid car would need approximately 10 kilograms of carbon soot, which would be deposited in about an hour using candles, Sharma explained.

For their next step, the researchers plan to develop a candle soot battery to test the technology further. They are also looking at testing hybrid materials that contain candle soot to determine if they can improve it for batteries.

This is not the first research to explore the potential of carbon from candle soot. In 2007, a study demonstrated that fluorescent nanoparticles, or CNPs, can be prepared from candle soot. Fluorescent CNPs are used in various biological applications such as biomolecular labeling, cellular imaging, tumor targeting, single particle tracking and long-term in vivo monitoring.

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