Liquid-based battery

We’ve all been there - you need your phone for an emergency call or a look a map and... the battery's dead. Getting better batteries could change not only our smartphone use, but it is one of the biggest challenges for getting people to take up electric vehicles. And while batteries have improved in leaps and bounds since the 80s, there’s still a very long way to go and progress has stalled in recent years. But the good news is that Glasgow chemist Lee Cronin has come up with a totally new battery concept: a super-charged liquid that you pump like petrol. Chris Smith asked him what's holding back present battery technology, and how his new system works...

Lee - Electricity is electrons flowing and the way we make batteries, or store power in batteries is we cram as many electrons as we can into the can if you like. When we squeeze them in they jostle up against one another and they heat up the battery material. And the battery literally starts to get a bit too hot and if it’s too hot then it can start to degrade.

Chris - How are you trying to surmount this?

Lee - We are pretty good at making nanoclusters, and these are basically taking lumps of metal at the nanoscale that we can add lots of electrons to in a very small space. And because we’re able to add them into this condensed space, they are able to go in without too much heat. And the beautiful thing is we can get lots of them in there and because the molecule is a nano type molecule, it’s a cage, it stays pretty good and doesn’t fall apart.

Chris - So this is a completely new battery material that you’re coming up with?

Lee - Yes. And also this material we have made a flow battery so the battery material’s are actually liquid. We actually pour the electrons into the nanocluster which is actually in water.

Chris - What is the chemical that’s enabling you to do this?

Lee - This is a derivative of tungsten oxide. It’s actually like a rich rust. A very expensive rust compared to say iron oxide but it’s the same principle. The oxide is able to store the electrons on the metal within the cluster. So if we were able to make a cluster out of say 18 metals, which we have here, we can get a whopping 18 electrons into a really small nano volume.

Chris - Okay. So paint a picture for me then because everyone’s familiar with what a Duracell battery, or an Eveready battery looks like: you know one of these cells that we buy and we put into a TV remote control. How would this differ from that?

Lee - In the Duracell, the battery has a solid electrolyte where the chemicals are mixed are a solid. But in our system, we’re able to flow the electrolyte around between the electrodes, which we call the “anode” and the “cathode.” The point is when the battery’s normally exhausted with the Duracell you either have to charge it up or you throw it away. In our battery what you can do is charge it up, but if you need a quick charge you just drain out the liquid and fill up the tank again. It’s just like a gasolene tank.

So we’re imagining the we could actually put this into an electric vehicle, and when the electric vehicle was flat you’d go to the petrol station. But rather than filling up with diesel or petrol, you’d remove the spent electrolyte and then pour in the fully charged new electrolyte. That would take a few seconds and then you could zoom away again in your electric car for many hundreds of miles.

Chris - But, critically, you could regenerate the electrolyte that’s exhausted?

Lee - Exactly. Because the material doesn’t degrade you just recycle it again. Probably take it away in a tanker to a power station, recharge it, and bring it back. And the beautiful thing is it uses all the liquid infrastructure we have so people would not get range anxiety about “can I find a plug, can I find some electricity?” They’re used to going to a petrol station and getting liquid and putting it in the tank.

Chris - How would your new electrolyte based system compare with the best the industry has to offer at the moment?

Lee - Actually, very well. In fact, it’s a little bit better practically than what is achieved right now and we do have a new idea using this that could make it up to five times better. But right now I’d say were about 1.5 times better but we could be many many times faster charging. Well not charging, but removing the electrolyte and putting in new stuff.

Chris - Is it safe?

Lee - Well, it’s corrosive. It’s like a lead acid battery; it’s pretty corrosive and you need to be careful that you don’t burn yourself and the materials you use are up to the job. But compared to a lead acid battery I guess it is pretty safe.