Our conquest in search of better battery for our mobile phones still continues. Again, continuing the series of our coverage on “Future of Battery Technologies”, let us take a look at Graphene Super Capacitors.
Our search was for a better compound with high energy density. Normal Li-Ion battery takes about 3-4 hours approximate time to fully charge up. We always wondered why it can’t be much faster!!!!
A team of international researchers led by UCLA’s Richard Kaner have created graphene super capacitors using a LightScribe DVD burner. These capacitors are both highly flexible and have energy and power densities better than existing conventional lithium-ion.
The LSG capacitors are capable of discharging at 20 watts per cm3, some three times higher than lithium ion. Also the energy density it holds is about 1.36 mill watt-hours per cm3, which is twice when compared to lithium-ion battery. Sounds good but is this technology within reach of mobile batteries?? The answer is absolutely yes.
Well engineers at Northwestern University have refined the same old Li-Ion battery we use with new anode inside it. In lithium ion batteries there is a graphite anode, a metal oxide cathode, and an electrolyte containing a lithium salt. Better specially-crafted graphene electrode can allow a lithium-ion battery to store 10 times as much power and charge 10 times faster and last longer, too.
Each lithium ion have to travel around the outer edge of each graphene layer but the researchers, with new anode made from sheets of graphene (graphite is simply millions of layers of graphene), have inserted millions of nano-holes (10-20nm) through each layer of graphene (picture below). This will allow them to jump through nano-holes directly.
Also introducing clusters of silicon between each layer of graphene; graphene on its own can only carry one lithium ion per six carbon atoms, but each silicon atom can hold four lithium ions. And if you do the math this compound effect will increase the storing and charging speed by 10 times. So our normal 1500 mAh battery can have power capacity worth 15000 mAh. And also it can be charged in about half an hour instead of 3-4 hours.
Isn’t it fabulous and exciting but wait we have something more. The charge/discharge cycles of The Northwestern battery is five times more effective than lithium ion battery. These graphene supercapacitors could really change the technology backdrop. Let us hope this technology is accepted and implemented at industrial scale and we might be able to see battery which can last almost a WEEK!!!
Give us feedback in comments below and let us know your views. Stay tuned for some other exciting future technologies of the batteries in the next blog.