GCN LAB IMPRESSIONS
A battery that lasts 10 times longer, charges 10 times faster?
- By Greg Crowe
- Nov 17, 2011
A battery is a battery, right? I mean, the idea of a chemical process to get the electrons to flow from one electrode to the other has been around forever. It’s even possible the ancient Mesopotamians had them. And unlike some other technologies, improvements in battery life haven’t exactly followed Moore’s Law.
I was pretty sure we weren’t going to see a huge improvement in their performance, until a whole new process was discovered to replace chemical batteries entirely. Shows what I know.
A team of researchers at Northwestern University has figured out a way to build the anode (negative electrode) in a standard lithium-ion battery (the type commonly used in most electronic devices today) to extend its charge by a factor of 10. What’s more, this design also allows the battery to recharge 10 times faster.
Lithium-ion batteries are called that because of the lithium ions that travel from the anode to the cathode (positive electrode) through a chemical process. The recharging process simply makes the ions go back to the anode.
However, the carbon-based material (atom-thick sheets called graphene) that makes up the anode can only hold one lithium ion for about every six carbon atoms in the material. Silicon can hold more ions, but unfortunately its changes in volume made silicon alone not viable for use in a battery.
So the Northwestern researchers did two things. First, they interspersed bits of silicon in among the carbon-based material. This upped the anode’s capacity, while the carbon helped counter the volume changes. Second, they strategically placed holes in the graphene sheets that allow the lithium ions to jump through as a shortcut on their way back during recharging.
So, in theory, you could use your smart phone for a week or so without charging, then bring it back to a full charge in about 15 minutes, which would be nice.
They haven’t said when this experimental design will be ready for mainline production, but I would guess within a year or two. And all this was just from looking at the anode — they haven’t even started on the cathode yet.
I, for one, can’t wait to spend all of the extra time that will be needed for testing devices in the lab that have 10 times the battery life. Uh, I will get overtime, right?
Greg Crowe is a former GCN staff writer who covered mobile technology.