Powering the Future
PHONE ALWAYS OUT OF BATTERY? MIZU NISHIKAWA-TOOMEY INTERVIEWS SCOTT BROWN ABOUT ENERGY ALTERNATIVES
Its 4am and I am lost in a far-away land known as Peckham. Although I had charged my phone the night before, excessive cat video watching in lectures earlier that day drained my battery. With no internet, and no maps, I am stranded.
Why is it that in 2015 we can land a probe on a comet travelling at 135,000 km/h but we cannot make a smart phone battery last for one day? What is being done to improve these battery lives? I spoke to businessman and scientist, Scott Brown, CEO of Nexeon.
Nexeon uses innovative technology to improve the life cycle and energy density of rechargeable batteries. While I dream of tea being free in the Print Room cafe, Scott dreams of a world free of disposable batteries, and where the consumption of materials and energy is drastically reduced.
“We need to replace non-rechargeable batteries with chargeable ones,” Scott explains. “If we could make a better performing rechargeable battery, people will be less inclined to use disposable ones. Another issue is electrical cars – if our batteries could be used in cars, drivers could travel further between charges, due to the higher energy density of our batteries”.
Brits throw away 600 million household batteries each year. If you were to line up those batteries end to end, they would reach from the U.K to Australia then back again. Not only does this contribute 22,000 tonnes of waste to landfill, harmful chemicals may seep out of these batteries into the ground and can contribute to soil and water pollution.
So why does the current design of rechargeable batteries lead to rapid decline of battery life?
“Most rechargeable batteries use carbon as the anode. (The anode and cathode carry the current to the electrical device from inside the battery). “
“Positive lithium ions will migrate from the negative cathode to the positive carbon anode during charging, and return to the negative cathode when discharging. The problem with carbon is it cannot absorb much of the positive lithium ions during charging and the battery is therefore limited in energy density or capacity.”
Many companies are trying to find a way around this problem with positive silicon anodes, providing different “flavours” – as Scott puts it – of silicon.
“The advantage of silicon is that it has a huge affinity for lithium and therefore high energy density batteries can be made using it. The disadvantage, however, is that silicon expands up to 300% of its original size during charging.”
This is a problem for rechargeable batteries as after several cycles the silicon becomes damaged and the battery’s energy density decreases. However, developments are being made.
“We’ve found a structure of silicon which is cost effective, as well as being able to expand and contract during use without damage. Test batteries we have made have large energy density and a longer life span than batteries made with other silicon materials. We hope to replace maybe not all but most of the carbon in the anodes of batteries with our silicon.” Successful transfer of these batteries onto the market will have a hugely positive environmental impact.
The responsibility cannot lie just within governments and international organizations such as the UN and the EU, it must also lie within researchers and private businesses. The future of energy is in batteries, and the future of business is in sustainable technology and engineering.
Hopefully, in 10 years time, I will be looking for my battery powered autopilot car to drive me home at 4 in the morning while I endlessly stream those cat videos from YouTube. For now, it’s just a dream.