Granite Geek: UNH Water-Powered Battery Project May Diversify Energy Opportunities

Dec 21, 2016

Most of the batteries we use in our daily life are made from chemicals, and many of those chemicals are toxic.  Researchers at the University of New Hampshire are working with technology that uses water instead of those toxic chemicals.  Water has not been a great material for building a battery, but this research may change that. 

Granite Geek David Brooks spoke with NHPR’s Peter Biello about this new research from UNH, and what it could mean for the future.  David is a reporter for the Concord Monitor, writer at granitegeek.org, and a regular guest on NHPR’s All Things Considered

The transcript has been edited for clarity. 

So, David, before we get into the water aspect of the new battery technology at UNH, tell us how batteries in general are supposed to work.

[Batteries are] a way to store electrical energy as chemical energy, because electrical energy just doesn’t store well; you can’t stick it in your pocket. And so the way it traditionally does this is it has a couple of different metals that are stuck into a usually a liquid. The metals are called electrodes, the liquid is called electrolytes. And the chemical interaction amongst those when a circuit is completed causes electrons to move from here to there or there to here, and in the process it creates a current or it stores a current.

And water hasn’t been a very good electrolyte in the past.  Why not?

It doesn’t chemically interact with any known electrodes, any known alloys or metals, in way that would make the electrons move when you want them to. The battery in your car is a lead-acid battery because it uses lead and acid, that was the first major one that was found. And it’s still quite effective, but it’s heavy and it’s toxic as all get-out. 

Everybody’s always wanted to use water an electrolyte, which is sort of the medium the metal is stuck in, for obvious reasons: it’s cheap, it’s easy to dispose of, and it’s non-toxic. But the question is can you find alloys or metals that will work as electrodes in water as an electrolyte in a way that will be able to store and transfer energy well?

And apparently UNH is close to doing that.

Yeah, they have research that indicates that… a meatal has been used in other attempts. They call these aqueous batteries because this is science, you have to call it something complicated – aqueous batteries and magnesium oxide is a particular metal that interacts with water in certain ways. But if you store too much voltage in it, if you use too much voltage in it, it interacts with the water in a way that gets in the way of the process. And the question is can you alter the magnesium oxide in a way that will be able to handle more voltage without this deposition happening in the water? 

UNH researcher Xiaowei Teng and his PhD students – a couple of his PhD students – have been working on this for a couple of years with a Department of Energy grant. And they believe they have found a way.  I have to admit I can’t really explain to you what they do. The way they describe it is they use a “well-ordered hydroxylated interphase that suppresses the gas evolution reactions.”

A hydroxylated interphase! Why didn’t you say so!

Absolutely! So it raises the amount of the voltage that can be used and stored in a way that shows great promise in making aqueous batteries – water batteries – actually commercially useful.

Spell out that promise for us. If this technology is commercially viable, what might it enable that we’re, as of right now, unable to do?

The idea is to supplant some existing battery technologies with a less toxic, safer variant – one that doesn’t explode as easily. We’ve heard of some exploding cell phone batteries.

What it won’t do, and what Dr. Teng admitted, is it’s not going to suddenly… even if it surpasses his wildest dreams in working and in terms of how cheap it is, it’s not going to show up everywhere. Because one of the things he talked about is that battery technology improves and matures as the world changes and we try to electrify everything – that’s sort of par what you have to do to de-carbonize industry – it’s going to require different kinds of batteries.  You’ll need some that the most important thing is that it’s small. You’re going to need some that the most important thing is it lasts a long time and can be charged at a certain depth in a certain amount of time quickly. You’ve got other ones that the most important thing is that it can hold a whole lot of charge and can release it and it doesn’t matter how long it is. So this will be, if all goes well and it seems to be so far, this will be one of a number of battery technologies that will be reshaping our future.