GCN LAB IMPRESSIONS

A battery that lasts 10 times longer, charges 10 times faster?

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?

Guys?


 

About the Author

Greg Crowe is a former GCN staff writer who covered mobile technology.

Reader Comments

Wed, Mar 28, 2012 Steve

The confusion I have is at what point in the design process are they? Is this a theoretical approach, have they modeled it, have they manufactured one yet? This article seems like it is expounding on a headline. Interesting, but not a good article

Mon, Nov 21, 2011 Captain Obvious

Generally, "breakthrough" announcements usually end with "...although commercialization is ten years away, or more, if they can get the bugs out."

Fri, Nov 18, 2011 Arty Watertown

A similar result to those mentioned in the article was obtained at MIT in 2008. It used doping in the anode similar to the process described and the process was licensed to A123 for use and a variety of advanced Li+ battery applications. My impression is that A123 has passed the industrial engineering hurdles and is now manufacturing these new batteries. The main customers are apparently auto manufacturers and these batteries are apparently key to the performance of newer plug-in hybrids like the volt. As mentioned in the previous comment, these devices address the issue of power density. It would be interesting to know how the Northwestern technology compares to the MIT technology and also if the two approaches are compatible. If you hadn't noticed, Greg, this is an assignment for a follow-up story by one of your dedicated readers!!

Fri, Nov 18, 2011

I enjoyed this article, short, simple, concise. I did not enjoy the comment "This article confuses a few of them", I saw nothing conflicting between what the commentor so ""expertly"" shared and the contents of the article.

Thu, Nov 17, 2011

Improvements in batteries can be confusing because there are many desirable specs. This article confuses a few of them. First, people want batteries that hold an enormous amount of energy. This is referred to as energy density. Second, people want to charge and recharge batteries very quickly. This is called power density. Third, people want batteries that can be charged/recharged numerous times without degrading over time. This is the cycle life of a battery or it's durability. The research you are referencing appears to address the power density and cycle life of a battery...not the energy density. Additionally, many believe there is not enough lithium in the world for mass adoption in the electrical vehicle market. We seem to be doing fine in the mobile device category however. Lastly, beware of battery improvement claims in general. It takes a very, very long time to go from lab to production. This has lead some to believe that real innovations won't come about until advanced semi-conductor fabrication techniques are brought to bear on the rather archaic processes used to make batteries.

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