0:00:02 > 0:00:06This fantastic prototype sports car is powered by a remarkable
0:00:06 > 0:00:08energy storage device -
0:00:08 > 0:00:12a device that we carry around in our pockets and a device that's helped
0:00:12 > 0:00:14revolutionise the modern world.
0:00:15 > 0:00:16The battery.
0:00:18 > 0:00:21In this lecture, I'm going to investigate one of the most
0:00:21 > 0:00:25important scientific challenges of our generation.
0:00:25 > 0:00:27What's the best way to store energy?
0:00:33 > 0:00:36To find out, we are going to try and get into
0:00:36 > 0:00:40the Guinness Book Of World Records with a very special battery.
0:01:17 > 0:01:22Welcome to my final 80th anniversary Christmas lectures.
0:01:22 > 0:01:27I'm Saiful Islam, I'm a professor of chemistry at the University of Bath.
0:01:28 > 0:01:34When we talk about energy storage, we're often talking about one thing,
0:01:34 > 0:01:38the battery. Try to imagine a world without them -
0:01:38 > 0:01:42you'd have no mobile phones, no laptops,
0:01:42 > 0:01:46tablet computers or even remotes for your TV.
0:01:47 > 0:01:50I think batteries are amazing.
0:01:50 > 0:01:53But they can be very, very familiar,
0:01:53 > 0:01:58so I wanted to show you an unusual and slightly, in fact, I think,
0:01:58 > 0:02:01quite scary, demonstration of what batteries can do.
0:02:01 > 0:02:04So I've rigged this up.
0:02:04 > 0:02:06This is...
0:02:07 > 0:02:12..an arc welder, not something I thought I'd be doing.
0:02:12 > 0:02:16It uses electricity to cut through solid metal.
0:02:16 > 0:02:20It's one of the most energy-intensive processes you can think of.
0:02:20 > 0:02:25The actual tip here can reach 20,000 Celsius,
0:02:25 > 0:02:31and that extractor fan there is going to take up the fumes.
0:02:31 > 0:02:36But the welder is hooked up to just a couple of ordinary car batteries
0:02:36 > 0:02:39and come with me and I'll show you what they look like.
0:02:42 > 0:02:47So right here are two ordinary car batteries and we've hooked them up
0:02:47 > 0:02:51but we've put them out here because there is a small chance
0:02:51 > 0:02:53they might explode.
0:02:53 > 0:02:57So let's try and set things up.
0:02:57 > 0:03:01So, I'm no welder, I'm just a humble chemist,
0:03:01 > 0:03:03but I'll be happy to give it a go.
0:03:03 > 0:03:06So this is my hand in glove.
0:03:08 > 0:03:12So it is really important at this stage, right, before I get down here...
0:03:12 > 0:03:14So if you can put your goggles on now.
0:03:21 > 0:03:23I tried something earlier.
0:03:24 > 0:03:25It wasn't a fantastic effort.
0:03:43 > 0:03:45Right.
0:03:46 > 0:03:49Let's see if that's better than my first attempt.
0:03:49 > 0:03:51Well, let's have a look.
0:03:51 > 0:03:57So if you look here, I tried to do RI twice.
0:03:57 > 0:04:01I don't think I'll give up my day job and become a welder.
0:04:01 > 0:04:07So I'd say that's my abstract period and that's my sort of dodgy period.
0:04:07 > 0:04:10So, anyway, I hope the sparks were flying there.
0:04:12 > 0:04:15So that is a very intensive process.
0:04:15 > 0:04:19But remember, that was done from the energy from a couple of
0:04:19 > 0:04:26car batteries. Storing energy is more important now than at any time
0:04:26 > 0:04:31in human history. It affects all aspects of our lives.
0:04:31 > 0:04:33So how many of you
0:04:33 > 0:04:35have got phones in your pockets?
0:04:35 > 0:04:38I imagine most of you.
0:04:38 > 0:04:40So why don't you get them out?
0:04:40 > 0:04:41Let's have a look at them.
0:04:42 > 0:04:45OK, and you can turn them on.
0:04:46 > 0:04:51So a simple question - how many of them are fully-charged?
0:04:51 > 0:04:52Who's got them fully-charged?
0:04:54 > 0:04:59Not that many. How many are less than half-charged?
0:04:59 > 0:05:00Right.
0:05:00 > 0:05:04And how many of you have actually run out of battery altogether?
0:05:06 > 0:05:07Just a few of you.
0:05:09 > 0:05:13So our phones often struggle to last a single day.
0:05:14 > 0:05:20Over the next hour, I'm going to try and do something truly amazing -
0:05:20 > 0:05:25I'm going to look at how we might supercharge a mobile phone
0:05:25 > 0:05:31and get it to last a whole year without plugging into the mains.
0:05:31 > 0:05:35So I'm sure all of you, and I know I would, would love one of those.
0:05:35 > 0:05:37So how much energy would that take?
0:05:38 > 0:05:41Look at this energy meter over here.
0:05:45 > 0:05:46OK, so...
0:05:48 > 0:05:51This meter uses units we can all understand -
0:05:51 > 0:05:53AA batteries.
0:05:53 > 0:06:00Our target for the year is about 800 AA batteries, which you will see,
0:06:00 > 0:06:02vroom, 800.
0:06:04 > 0:06:06So, to give you a better feel of what that looks like,
0:06:06 > 0:06:09I've got this large container and I'm going to go up the...
0:06:11 > 0:06:13..ladder to pour them in.
0:06:13 > 0:06:15Oh, they are down there.
0:06:15 > 0:06:18Erm, I think I need a volunteer to help out.
0:06:18 > 0:06:20Any volunteers to help out?
0:06:20 > 0:06:23So do you want to come round? Yes, come over.
0:06:27 > 0:06:28Can I take your name?
0:06:30 > 0:06:31Asheen?
0:06:31 > 0:06:35This is Asheen, he's going to help me put those batteries in there.
0:06:35 > 0:06:38So if you could pass me one bucket at a time.
0:06:38 > 0:06:43So this is what the 800 AA batteries look like if you wanted to power
0:06:43 > 0:06:45your mobile phone for a whole year.
0:06:49 > 0:06:52OK. Do you want to give me another bucket there?
0:06:52 > 0:06:53So, that's...
0:06:54 > 0:06:56..two.
0:06:56 > 0:06:57So this is...
0:07:01 > 0:07:02Just two more to go.
0:07:11 > 0:07:12And the last one.
0:07:12 > 0:07:15Let's see. So you can see, it's already really gone up
0:07:15 > 0:07:18to a high height. And then, the last lot.
0:07:21 > 0:07:23So it's already gone to the top.
0:07:23 > 0:07:28So that's what you would need to power your phone for a year.
0:07:28 > 0:07:31Can you imagine trying to carry that around in your pocket?
0:07:31 > 0:07:34You'd need some very large pockets there.
0:07:34 > 0:07:37Thank you, thank you very much.
0:07:37 > 0:07:40Let's thank him.
0:07:40 > 0:07:43So you can see already it's going to be a tough challenge.
0:07:43 > 0:07:49The key is storing more energy in a smaller size and a lighter weight.
0:07:49 > 0:07:54We want to increase something we call energy density.
0:07:54 > 0:07:59But first, it always helps to know our scientific history.
0:07:59 > 0:08:03Who made the first chemical battery?
0:08:04 > 0:08:08So one of the earliest batteries is right here in the vaults
0:08:08 > 0:08:12of the Royal Institution and we can show it to you right now.
0:08:16 > 0:08:20So this is our museum curator, Charlotte, and she'll be holding it.
0:08:20 > 0:08:23I'm not allowed to touch it because it's very precious.
0:08:24 > 0:08:27Here is a voltaic pile.
0:08:28 > 0:08:34It was made by Alessandro Volta in Italy and given to Michael Faraday
0:08:34 > 0:08:36nearly 200 years ago.
0:08:36 > 0:08:38So what is it made of?
0:08:38 > 0:08:39So you can see,
0:08:39 > 0:08:45it's got these kind of metal slabs and they are the metal electrodes,
0:08:45 > 0:08:48so zinc and copper.
0:08:48 > 0:08:50Between them, I don't know whether you can see on the camera,
0:08:50 > 0:08:53there's kind of cloth, a bit of cloth there,
0:08:53 > 0:08:56and that would have been soaked with salt water.
0:08:56 > 0:09:02It might look crude, but it did store a small electrical charge.
0:09:02 > 0:09:06So you'd probably need 1,000 of these to power your current
0:09:06 > 0:09:08modern mobile phone.
0:09:09 > 0:09:13But this was a key moment in the history of science.
0:09:13 > 0:09:19It was one of the first times anyone had been able to store electricity.
0:09:19 > 0:09:23It gave birth to a whole new field called electrochemistry.
0:09:23 > 0:09:24So thank you, Charlotte, thank you.
0:09:33 > 0:09:38So the voltaic pile I've just shown you and all batteries basically work
0:09:38 > 0:09:40on the same principle.
0:09:40 > 0:09:43A good way of explaining batteries
0:09:43 > 0:09:46is with a very complex piece of machinery.
0:09:48 > 0:09:50A lemon.
0:09:50 > 0:09:54And here, we're going to actually...
0:09:54 > 0:09:55Something I prepared earlier.
0:09:57 > 0:10:01We've got basically how a lemon battery works.
0:10:03 > 0:10:08As before, with that voltaic pile, you've got a metal electrode,
0:10:08 > 0:10:10in this case, a copper nail.
0:10:10 > 0:10:16And we've got at the end of this one, you can see a magnesium strip,
0:10:16 > 0:10:18which is the other electrode.
0:10:18 > 0:10:20So let's have a look at this voltmeter.
0:10:20 > 0:10:25So if you look at the value at the moment, it should be reading zero.
0:10:25 > 0:10:30So if I plug this in, it should, hopefully, give us a voltage.
0:10:33 > 0:10:35So you can see that
0:10:35 > 0:10:39and it's gone up to 1.42, 1.43 volts.
0:10:39 > 0:10:40Actually, 1.44.
0:10:40 > 0:10:43So actually it's showing a voltage.
0:10:43 > 0:10:47But these are the Christmas lectures.
0:10:47 > 0:10:50One lemon is not enough.
0:10:50 > 0:10:52So I wanted to go large.
0:10:52 > 0:10:56I told the Royal Institution I wanted to go very large,
0:10:56 > 0:11:00and it's so large it won't even squeeze into this lecture theatre.
0:11:00 > 0:11:03So follow me and I'm going to show you what it looks like.
0:11:07 > 0:11:12So this here is the biggest lemon battery the world has ever seen.
0:11:12 > 0:11:14It's gigantic.
0:11:14 > 0:11:17Look at it. Over 1,000 lemons.
0:11:17 > 0:11:20In fact, we cut them in half and sliced them
0:11:20 > 0:11:26to make 2,016 lemon slices, so this is cutting-edge technology.
0:11:26 > 0:11:27LAUGHTER
0:11:27 > 0:11:31Let me get a closer look at one of these batteries, OK.
0:11:31 > 0:11:34Joe, do you want to get closer to one of these batteries?
0:11:34 > 0:11:38So look - this is exactly one of the batteries that I showed you inside,
0:11:38 > 0:11:41with the electrodes and clips.
0:11:42 > 0:11:46So let me meet the adjudicator from the Guinness Book Of World Records,
0:11:46 > 0:11:49Craig, Craig Glenday, great to meet you.
0:11:49 > 0:11:53So let's move over to the voltmeter.
0:11:53 > 0:11:57So as you know, there were some issues with some of the lemons,
0:11:57 > 0:11:59so we weren't sure if we were going to quite reach the target.
0:11:59 > 0:12:02But what's the target we need to get to, to break a world record?
0:12:02 > 0:12:05To achieve the official Guinness World Records title,
0:12:05 > 0:12:07you must exceed 1,000 on the meter.
0:12:07 > 0:12:10So we are looking for 1,000 or more to be successful.
0:12:10 > 0:12:14OK, so, I'm going to do the connection
0:12:14 > 0:12:17and it rests on whether I can connect them up properly
0:12:17 > 0:12:20and we're going to pass that total.
0:12:20 > 0:12:23But I need a very large...
0:12:24 > 0:12:28..countdown from the audience so I can hear it from here.
0:12:28 > 0:12:30So give me a countdown.
0:12:30 > 0:12:34AUDIENCE: Three, two, one.
0:12:37 > 0:12:39So what does it read, Craig?
0:12:39 > 0:12:42I'm very pleased to say it reads 1,275,
0:12:42 > 0:12:45so you've more than broken the Guinness World Records title.
0:12:45 > 0:12:47- Congratulations.- Great!
0:12:53 > 0:12:56We've done it! We've got a world record!
0:12:58 > 0:12:59Yay!
0:13:16 > 0:13:20That was exciting. It was actually very nerve-racking and it was quite
0:13:20 > 0:13:22close to the edge, just before this lecture.
0:13:22 > 0:13:27So this may be the biggest lemon battery in the world.
0:13:27 > 0:13:31But could it power our phone for a year?
0:13:31 > 0:13:33We have a scientific term for that.
0:13:33 > 0:13:35No way, Jose.
0:13:37 > 0:13:41To really understand how that lemon battery worked,
0:13:41 > 0:13:43we need to get at the atomic level,
0:13:43 > 0:13:45we need to understand the chemistry.
0:13:45 > 0:13:48And this, right in front of you,
0:13:48 > 0:13:51is a scaled up version of that lemon battery.
0:13:51 > 0:13:53So let me explain what we have here.
0:13:53 > 0:13:58So this is the magnesium strip, that's one of the electrodes.
0:13:58 > 0:14:01And here we have a very oversized nail,
0:14:01 > 0:14:04the copper nail that was in there.
0:14:04 > 0:14:08And in between that is a representation of the lemon juice,
0:14:08 > 0:14:12the electrolytes, in between those two electrodes.
0:14:12 > 0:14:14So that is the battery.
0:14:14 > 0:14:15So what's going around the side?
0:14:15 > 0:14:18So around here is...
0:14:20 > 0:14:22..the wire, the external circuit,
0:14:22 > 0:14:25where the electrons should pass through.
0:14:25 > 0:14:29OK. So that is basically the battery and the external circuit.
0:14:29 > 0:14:32So I need a volunteer, please.
0:14:32 > 0:14:35And I think we have one already arranged, so, Isaac,
0:14:35 > 0:14:37do you want to come down?
0:14:39 > 0:14:40OK.
0:14:40 > 0:14:43So, Isaac, do you want to come round to the front here?
0:14:43 > 0:14:45So, we've got...
0:14:46 > 0:14:48..a board for you to wear.
0:14:48 > 0:14:50I know it's not a very fetching board,
0:14:50 > 0:14:54but it tells us exactly what you are for this evening.
0:14:54 > 0:15:02So you are, for this evening only, you're going to be a magnesium atom.
0:15:02 > 0:15:04OK? So what does a magnesium atom have?
0:15:04 > 0:15:06- It has...- Is it electrons?
0:15:06 > 0:15:08Electrons, it does.
0:15:08 > 0:15:13So if you stay around just to the side here, right to the side there.
0:15:13 > 0:15:16So you're going to hold these two electrons.
0:15:16 > 0:15:18So get those two hands ready.
0:15:19 > 0:15:21The thing about these electrons,
0:15:21 > 0:15:23they do wander off, they're very mobile.
0:15:23 > 0:15:25So let's have a look. So if you hold that.
0:15:27 > 0:15:30Just to make it more difficult for you, I know you are not a juggler,
0:15:30 > 0:15:32you're going to hold those two electrons like that.
0:15:32 > 0:15:36So this is the magnesium atom with two electrons.
0:15:36 > 0:15:41So electrons are the smallest particles of the atom.
0:15:41 > 0:15:45They act as carriers of electrical charge.
0:15:45 > 0:15:49So when we talk about electricity, we are really talking about
0:15:49 > 0:15:51electrons moving.
0:15:51 > 0:15:53So what happens when we connect the wire?
0:15:53 > 0:15:56So you can see already that there is a clip there,
0:15:56 > 0:16:01already connected to that electrode so there's one clip here
0:16:01 > 0:16:06representing our other connection.
0:16:06 > 0:16:11So I'm going to connect that to the magnesium electrode and I'm going to
0:16:11 > 0:16:13connect it to the circuit in a second.
0:16:13 > 0:16:16And before that, can you get ready with your electron?
0:16:16 > 0:16:19So if you hold it there but don't let it roll it yet.
0:16:19 > 0:16:22So just hold it there and when I connect them,
0:16:22 > 0:16:26just give it a little nudge, a little push around that circuit, OK.
0:16:26 > 0:16:30So let me make the connection now and then give it a little nudge, yeah.
0:16:30 > 0:16:33So this electron moving is electricity and actually,
0:16:33 > 0:16:36it would power that lamp. There you are.
0:16:36 > 0:16:37Here's another electron.
0:16:39 > 0:16:41There you are. So those electrons, ie,
0:16:41 > 0:16:46these large balls representing them are actually powering a device.
0:16:46 > 0:16:50And that's how the start of that process works.
0:16:50 > 0:16:52But there's another driving force -
0:16:52 > 0:16:57that magnesium atom has just lost two negatively charged electrons.
0:16:57 > 0:16:58So what happens there?
0:16:58 > 0:16:59It becomes...
0:17:02 > 0:17:04..a magnesium ion.
0:17:04 > 0:17:09Yes. And there is a driving force that pushes that ion
0:17:09 > 0:17:10across the pool, the electrolyte.
0:17:10 > 0:17:14So do you want to go through that pool, but very carefully, because it's full of balls.
0:17:14 > 0:17:16Right to the other side.
0:17:16 > 0:17:18So, if you come to the side here.
0:17:20 > 0:17:22Great. So you're an ion now.
0:17:22 > 0:17:24How you feeling? Positive?
0:17:24 > 0:17:25Great.
0:17:25 > 0:17:27LAUGHTER
0:17:27 > 0:17:32So that's basically how that lemon battery worked.
0:17:32 > 0:17:33What happens here,
0:17:33 > 0:17:37there are some further chemical reactions to balance the charges.
0:17:38 > 0:17:39But this is not rechargeable.
0:17:39 > 0:17:43What happens is that, once we've used up all the metal,
0:17:43 > 0:17:48it goes from that side to this side and if it uses up all that metal,
0:17:48 > 0:17:51you actually don't produce any more electricity.
0:17:51 > 0:17:54So this is not a rechargeable battery
0:17:54 > 0:17:56like the ones that you find in your phones.
0:17:56 > 0:17:58Thank you, Isaac, for helping out.
0:18:00 > 0:18:03And thank you very much. OK. Do you want to go back to your place?
0:18:12 > 0:18:14Almost all of the rechargeable batteries
0:18:14 > 0:18:18in your phones and laptops rely on a single rare
0:18:18 > 0:18:20and extraordinary metal.
0:18:20 > 0:18:22As part of our 80th celebrations,
0:18:22 > 0:18:27we are inviting Christmas lecturers past to help out.
0:18:27 > 0:18:31To introduce you to the properties of this material,
0:18:31 > 0:18:33please welcome the 2012 Christmas Lecturer
0:18:33 > 0:18:36and fellow chemist, Dr Peter Wothers.
0:18:39 > 0:18:41- Hi there, Peter.- Hi there.
0:18:46 > 0:18:48Peter, I'm so glad you could join us.
0:18:48 > 0:18:49It's great to be back.
0:18:49 > 0:18:53So, tell us about your lectures back four years ago, 2012.
0:18:53 > 0:18:55So we were looking at the chemistry of the elements,
0:18:55 > 0:18:58so all the different elements around us and how important they are
0:18:58 > 0:19:02- in our everyday lives. - I really enjoyed watching them.
0:19:02 > 0:19:05So what was your favourite demonstration amongst the lectures?
0:19:05 > 0:19:09I think my favourite one was actually when we burnt a diamond
0:19:09 > 0:19:11in oxygen gas.
0:19:11 > 0:19:15So Harry Kroto, Nobel Prize winner, came down and helped out and it was
0:19:15 > 0:19:19just absolutely fantastic to see this tiny little diamond in the gas
0:19:19 > 0:19:23there just glowing beautifully like a little star trapped in a jar.
0:19:23 > 0:19:25- It is quite stunning to see, isn't it?- That's right, yes.
0:19:25 > 0:19:29There are no flames coming from this, so this is just,
0:19:29 > 0:19:34again, the heat of the reaction as the carbon combines with the oxygen
0:19:34 > 0:19:38that's present flowing through here forming carbon dioxide.
0:19:38 > 0:19:40That is absolutely stunning.
0:19:40 > 0:19:42Just look at that, it's glowing all by itself,
0:19:42 > 0:19:44it's absolutely brilliant.
0:19:44 > 0:19:46So I've got you on for a specific reason -
0:19:46 > 0:19:50I've mentioned this strange material.
0:19:50 > 0:19:52Can you tell us a bit more about it?
0:19:52 > 0:19:55Yes, so, this is one of the elements and it's a metal
0:19:55 > 0:19:58and I've got a little sample in the jar here.
0:20:00 > 0:20:03This metal is actually incredibly reactive,
0:20:03 > 0:20:06much more reactive than a lump of iron would be.
0:20:06 > 0:20:10It's in fact so reactive that it reacts with air and with water,
0:20:10 > 0:20:12as we shall see in a minute.
0:20:12 > 0:20:14So this is...
0:20:15 > 0:20:18Let me just take a piece out. This is in the form of foil.
0:20:22 > 0:20:24And you can see it's just a nice,
0:20:24 > 0:20:29shiny metal there and it's the element lithium.
0:20:29 > 0:20:34And this is actually in fact so light that it will float on water,
0:20:34 > 0:20:36- which is rather nice. - Let's have a see.
0:20:36 > 0:20:38- OK, but you might want to step back a little bit.- I will do.
0:20:38 > 0:20:40OK, there we go.
0:20:40 > 0:20:44And that's because it's instantly reacting with the water.
0:20:45 > 0:20:48The lithium metal is turning into lithium ions,
0:20:48 > 0:20:51which are dissolving in the water there and also giving out
0:20:51 > 0:20:54hydrogen gas and forming an alkaline hydroxide solution.
0:20:57 > 0:20:59- It's gone already.- It's great.
0:20:59 > 0:21:04Well, thank you, Peter, for telling us about this strange material,
0:21:04 > 0:21:07the lithium metal, and with an elegant demonstration.
0:21:07 > 0:21:10- Let's thank Peter Wothers once again.- Thank you.
0:21:21 > 0:21:26So why keep such a reactive metal in our pockets?
0:21:26 > 0:21:29What makes lithium so good?
0:21:29 > 0:21:33To illustrate this I've got a pair of lead acid batteries here.
0:21:33 > 0:21:36How much work can they do?
0:21:36 > 0:21:40Well, we've decided to show them a slightly different way.
0:21:40 > 0:21:44We've calculated how far they would turn a famous London landmark.
0:21:44 > 0:21:48So on this screen, you should see...
0:21:48 > 0:21:52This is just a time-lapse photography of the London Eye.
0:21:52 > 0:21:55Those lead acid batteries can actually turn the London Eye
0:21:55 > 0:21:59a certain amount. So let's see how much that could be.
0:22:00 > 0:22:02So we can see,
0:22:02 > 0:22:06it's only about 6%, OK.
0:22:06 > 0:22:12That would be around 27 metres of those pods moving round.
0:22:12 > 0:22:16These are lithium ion batteries
0:22:16 > 0:22:20of the same weight as our lead acid ones there.
0:22:20 > 0:22:24So let's see what they would do to this London Eye.
0:22:24 > 0:22:26So let's have a look. They would go round...
0:22:29 > 0:22:31..25%.
0:22:31 > 0:22:35So it moves the pods over 100 metres.
0:22:35 > 0:22:39And that's because a lithium battery stores a lot more energy
0:22:39 > 0:22:42than any older lead acid battery of the same weight.
0:22:42 > 0:22:46It's what we call a higher energy density.
0:22:47 > 0:22:50And this has big implications.
0:22:50 > 0:22:55It's a great pleasure to welcome the 1987 Christmas Lecturer and previous
0:22:55 > 0:23:01director of the Royal Institution, Professor Sir John Meurig Thomas.
0:23:01 > 0:23:02APPLAUSE
0:23:06 > 0:23:08Thank you very much.
0:23:08 > 0:23:09Thank you.
0:23:15 > 0:23:16Your lectures were some time ago.
0:23:16 > 0:23:19What was the subject that you covered back then?
0:23:19 > 0:23:24Crystals and lasers and I dealt mainly with crystalline materials.
0:23:24 > 0:23:29Crystalline platinum in particular, not crystalline lithium.
0:23:29 > 0:23:32Well, related to that, I've got you on for a specific reason,
0:23:32 > 0:23:35holding a very interesting device. Tell us about what you are holding.
0:23:35 > 0:23:40Well, this is a mobile phone manufactured in Texas in 1983.
0:23:40 > 0:23:43It cost £4,000.
0:23:43 > 0:23:46It's about 5lbs in weight.
0:23:46 > 0:23:49It could allow you to speak for 30 minutes,
0:23:49 > 0:23:54but you needed ten hours to charge it.
0:23:54 > 0:23:56So I didn't buy one, I didn't buy one.
0:23:56 > 0:24:00OK. So, Sir John, I think we've got some footage
0:24:00 > 0:24:01from a previous lecture.
0:24:01 > 0:24:06It's Professor David Pye of Queen Mary College, as it then was.
0:24:06 > 0:24:09Find the phone under your seat there, it's ringing.
0:24:09 > 0:24:13OK. Would you like to press the orange button please?
0:24:13 > 0:24:16Take the call, then use it as an ordinary phone.
0:24:17 > 0:24:19Hold it up to your ear.
0:24:20 > 0:24:23Hello. Can you hear me on the phone?
0:24:23 > 0:24:25- Very clearly.- Good.
0:24:25 > 0:24:26Can you tell me your name please?
0:24:26 > 0:24:29Charles.
0:24:30 > 0:24:33Great. Sir John, it's been a real pleasure and I'm glad you could
0:24:33 > 0:24:37join us to describe that particular device.
0:24:37 > 0:24:38So thank you very much.
0:24:38 > 0:24:40It's a delight to be here.
0:24:40 > 0:24:41Thank you.
0:24:49 > 0:24:54Lithium ion batteries first came on the market in the early 1990s.
0:24:55 > 0:24:59Probably way before most of you were born, actually.
0:24:59 > 0:25:04They've helped power a worldwide portable revolution.
0:25:04 > 0:25:07They've changed all our lives.
0:25:07 > 0:25:11So why are lithium ion batteries so much better at storing energy?
0:25:11 > 0:25:15To understand that, we need to get back to chemistry,
0:25:15 > 0:25:17which is where I like to be.
0:25:17 > 0:25:23So lithium has the smallest atoms or ions of any metal
0:25:23 > 0:25:25in the periodic table.
0:25:25 > 0:25:29So this is just a lithium atom,
0:25:29 > 0:25:33but how does it compare to another atom in the periodic table?
0:25:33 > 0:25:35So I'm going to hand it over to a couple of people here.
0:25:35 > 0:25:37Can you just hold those?
0:25:37 > 0:25:42So this is sort of a relative scale.
0:25:42 > 0:25:44You've got lithium
0:25:44 > 0:25:47and you've got the potassium.
0:25:47 > 0:25:50And if you can hold those, you can see quite clearly
0:25:50 > 0:25:53that lithium is a lot smaller
0:25:53 > 0:25:59and the more ions you can pack into a battery or into a space,
0:25:59 > 0:26:01the more energy you can store.
0:26:01 > 0:26:05In fact, you can cram more lithium ions, the small lithium ions,
0:26:05 > 0:26:09into the same space than any other metal.
0:26:09 > 0:26:14So this gives lithium batteries their high energy density.
0:26:15 > 0:26:17Because lithium ions are so tiny,
0:26:17 > 0:26:21it's very difficult to see them using experiment alone.
0:26:22 > 0:26:27So, as a chemist, I'm lucky that my research can use
0:26:27 > 0:26:32modern supercomputers to model what is happening inside batteries
0:26:32 > 0:26:34at the atomic level.
0:26:34 > 0:26:36In fact, at parties,
0:26:36 > 0:26:38when I get invited, that is,
0:26:38 > 0:26:43when people ask me what I do, I sometimes say, "I model."
0:26:44 > 0:26:50And this is a computer model of the atomic structure of that lithium,
0:26:50 > 0:26:52of a lithium battery material.
0:26:52 > 0:26:55So this is a lithium cobalt oxide electrode.
0:26:55 > 0:26:59The cobalts are in purple, the oxygens are in red.
0:26:59 > 0:27:03We can see the lithium ions zipping through between the channels.
0:27:03 > 0:27:09So it's a very sheet-like structure and the important stuff is happening
0:27:09 > 0:27:13between the sheets, so we can see the lithium ion just zipping through.
0:27:13 > 0:27:18So they just indicate very fast ion motion.
0:27:18 > 0:27:20So when you charge up your phone tonight,
0:27:20 > 0:27:25probably Snapchatting to late in the evening,
0:27:25 > 0:27:29when you see those red and green symbols, they just indicate
0:27:29 > 0:27:33that tiny lithium ions are moving through a battery material.
0:27:33 > 0:27:36Those tiny lithium ions are moving through those sheets.
0:27:38 > 0:27:41But as you may have seen in the news recently,
0:27:41 > 0:27:45batteries sometimes go wrong.
0:27:45 > 0:27:48They overheat and it's usually due to short circuiting
0:27:48 > 0:27:51and I should stress that this is a very rare event,
0:27:51 > 0:27:54considering the billions of cells that have been sold
0:27:54 > 0:27:57practically every week.
0:27:57 > 0:28:01So we've set up a demonstration and this one is so dangerous
0:28:01 > 0:28:03that we couldn't actually do it in the lecture theatre.
0:28:03 > 0:28:08So we're doing it outside and we've set it up on the roof.
0:28:08 > 0:28:12So what you see there is a lithium battery pack.
0:28:12 > 0:28:15It's within a Perspex box, and right above it
0:28:15 > 0:28:21you can just about see a tube and at the top of the tube,
0:28:21 > 0:28:24you will see a giant nail.
0:28:24 > 0:28:28And it's going to go straight down into that lithium ion battery.
0:28:28 > 0:28:33And this is a serious point, do not attempt this at home.
0:28:33 > 0:28:36OK. It's going to be pulled by that small string there,
0:28:36 > 0:28:37that's going to release the rod
0:28:37 > 0:28:39and that nail's going to go straight down.
0:28:39 > 0:28:42So I think we need a countdown here, all right?
0:28:42 > 0:28:44Another countdown.
0:28:44 > 0:28:46ALL: Three, two, one.
0:28:56 > 0:28:59So what you are seeing there is the reaction right on that
0:28:59 > 0:29:00lithium ion battery.
0:29:04 > 0:29:07So, as you can see, that is an intense reaction,
0:29:07 > 0:29:10just from that nail going right through that lithium ion battery.
0:29:10 > 0:29:12So what's happening there?
0:29:13 > 0:29:17So what's happening is that the nail connects the two electrodes
0:29:17 > 0:29:22and short-circuits the battery, which makes it overheat.
0:29:22 > 0:29:26And this mimics the short-circuiting caused by bad battery design.
0:29:28 > 0:29:31But it's not the lithium that explodes.
0:29:31 > 0:29:35It's actually something else.
0:29:35 > 0:29:38It's the liquid electrolyte that sits between
0:29:38 > 0:29:40the two electrodes.
0:29:40 > 0:29:45And that electrolyte is made up of a lithium salt in a solvent,
0:29:45 > 0:29:48and that solvent is highly flammable.
0:29:48 > 0:29:52Get it too hot and it simply erupts out of the casing.
0:29:52 > 0:29:56So we're going to see a demonstration of this right now.
0:29:56 > 0:29:59Natasha, I think we're ready, so give us a demonstration.
0:30:03 > 0:30:04Great.
0:30:09 > 0:30:10Thank you.
0:30:14 > 0:30:17OK, so that's a very violent reaction.
0:30:17 > 0:30:21So this overheating is sometimes called thermal runaway.
0:30:23 > 0:30:25Which is a very rare event.
0:30:25 > 0:30:29Obviously, as long as you don't drive a nail through your battery
0:30:29 > 0:30:33or phone. So, let's get back to our original question.
0:30:33 > 0:30:37Can we power our phone for a whole year
0:30:37 > 0:30:39without plugging in to the mains?
0:30:39 > 0:30:45Well, we've been working very hard behind the scenes, and guess what?
0:30:47 > 0:30:49We've done it.
0:30:49 > 0:30:55Here it is. We've done the maths and this would definitely run your phone
0:30:55 > 0:30:58for a whole year. Inside, as you can see,
0:30:58 > 0:31:01are several lithium ion batteries,
0:31:01 > 0:31:03the size of car batteries wired together.
0:31:05 > 0:31:08I need a volunteer here.
0:31:08 > 0:31:11Yes. Yes, front row, come on over.
0:31:18 > 0:31:22So, this is on a sort of rucksack.
0:31:22 > 0:31:24Oh, yes, can I take your name?
0:31:24 > 0:31:26- Adam.- Adam, sorry.
0:31:26 > 0:31:29Adam, well, Adam, you're going to try and lift that up.
0:31:29 > 0:31:33So why don't you come round and give it a good pull up.
0:31:33 > 0:31:36You're probably stronger than I am, so can you try and lift that up?
0:31:36 > 0:31:37- This?- Yeah.
0:31:38 > 0:31:39That is heavy, isn't it?
0:31:41 > 0:31:43Would you like to carry that with your mobile phone?
0:31:43 > 0:31:46- No.- Right, well, you've given that a good attempt,
0:31:46 > 0:31:48so come over on this side here.
0:31:48 > 0:31:50In fact, do you know how much that weighs?
0:31:50 > 0:31:55You probably could tell - that weighs 30 kilos.
0:31:55 > 0:31:57Actually, I can barely lift it as well.
0:31:57 > 0:32:00So you're not going to put that very soon into your pocket,
0:32:00 > 0:32:03unless you've got very large pockets.
0:32:03 > 0:32:07So to make this work, we need somebody else to help out.
0:32:07 > 0:32:11Please welcome Britain's strongest woman Andrea Thompson.
0:32:16 > 0:32:17Thank you.
0:32:21 > 0:32:23Thank you, Andrea, for joining us.
0:32:23 > 0:32:25Thanks for having me.
0:32:25 > 0:32:27You are Britain's strongest woman.
0:32:27 > 0:32:30What did you have to do to get that accolade?
0:32:31 > 0:32:37Well, I had to pick up 220 kilos in my hands, pull a truck,
0:32:37 > 0:32:39a three-tonne truck
0:32:39 > 0:32:43and lift a series of atlas stones from 80-120 kilos.
0:32:43 > 0:32:45A three-tonne truck?
0:32:45 > 0:32:48- Yes.- So how far did you move with that?
0:32:48 > 0:32:4920 metres.
0:32:49 > 0:32:52- 20 metres?- Yeah. It was tough.- Oh, right!
0:32:52 > 0:32:54Well, let's see what you can do with this.
0:32:55 > 0:32:58As you can see, we've got some straps here, so I wonder if you
0:32:58 > 0:33:01could pick that up and see if you can put that on your back.
0:33:01 > 0:33:03- OK.- Let's give it a go.
0:33:03 > 0:33:05So that's 30 kilos, remember.
0:33:10 > 0:33:11It's a bit of a tight strap.
0:33:14 > 0:33:15- There you are.- Thank you.
0:33:15 > 0:33:17- Does that fit now?- That's fine.
0:33:18 > 0:33:19Oh, yes!
0:33:20 > 0:33:22That looks quite snug.
0:33:22 > 0:33:23Yes!
0:33:31 > 0:33:32That might be a solution for Andrea,
0:33:32 > 0:33:35but I don't think it's practical for everyone else.
0:33:35 > 0:33:37So, you can see, it's a possible solution,
0:33:37 > 0:33:40but not quite a practical one.
0:33:40 > 0:33:43You're going to carry that around for a whole year next to your phone.
0:33:44 > 0:33:47Let's thank Adam, once again.
0:33:47 > 0:33:51And we're going to thank Andrea. Thank you. Can you do us a favour?
0:33:51 > 0:33:55- Can you take that off with you?- Of course I will.- Thank you. Thank you.
0:34:04 > 0:34:06So can we do better?
0:34:06 > 0:34:10Can we help our phones last longer on a single charge?
0:34:11 > 0:34:15So we've talked about more powerful batteries, but obviously,
0:34:15 > 0:34:18if your phone uses less,
0:34:18 > 0:34:20then obviously it would last longer.
0:34:20 > 0:34:24So which function on your phone uses the most energy?
0:34:24 > 0:34:28Well, to answer this question, we need to smash open
0:34:28 > 0:34:30someone's smartphone.
0:34:33 > 0:34:36Actually, at this point, I would love to use my daughter's,
0:34:36 > 0:34:38but I couldn't possibly do that.
0:34:38 > 0:34:40So, any volunteers to have their phone smashed?
0:34:40 > 0:34:43Yes. Give us your phone.
0:34:43 > 0:34:45OK. Right, let's put it there.
0:34:45 > 0:34:46So.
0:34:47 > 0:34:50We need a countdown for this, OK.
0:34:50 > 0:34:54So, three, two, one.
0:34:54 > 0:34:56No, no, no.
0:34:57 > 0:34:59No, of course I couldn't do that.
0:35:01 > 0:35:04Don't worry, we've got our own set up here.
0:35:04 > 0:35:08So this is obviously something again we've prepared earlier.
0:35:08 > 0:35:11It has a voltmeter there and a typical mobile phone.
0:35:13 > 0:35:15Mobile phones do lots of things, OK.
0:35:15 > 0:35:21And this just actually gives an indication of the energy
0:35:21 > 0:35:24used by the different functions
0:35:24 > 0:35:26within that mobile phone.
0:35:26 > 0:35:30And the numbers are really a relative number,
0:35:30 > 0:35:32so don't worry about the units exactly,
0:35:32 > 0:35:34but just look at the relative values.
0:35:34 > 0:35:40So at the moment, you can see the relative values are fairly low, OK.
0:35:40 > 0:35:43And that's the phone on idle.
0:35:43 > 0:35:44So now...
0:35:45 > 0:35:47..I think we're just turning it on.
0:35:47 > 0:35:51And you can see straight away, just by turning it on,
0:35:51 > 0:35:54the energy usage has gone up.
0:35:54 > 0:35:58So if you look at the photo function, it whacks up.
0:35:58 > 0:36:05Look at that. Taking photos, you can see the energy usage
0:36:05 > 0:36:08sometimes touches numbers as high as 400.
0:36:08 > 0:36:15And then you've got to use the internet to transmit that photo.
0:36:15 > 0:36:17So this is the Wi-Fi.
0:36:17 > 0:36:20So Wi-Fi drops down a bit, but still,
0:36:20 > 0:36:23you've got relative energy usage.
0:36:23 > 0:36:29And then lastly, I think we'll go on to Twitter and go to the
0:36:29 > 0:36:35RI website and I think you'll see a very dodgy photo.
0:36:35 > 0:36:37There you are. So again,
0:36:37 > 0:36:41you can see the different functions are using different relative amounts
0:36:41 > 0:36:45of energy. So taking photos and having your screen lit up
0:36:45 > 0:36:47uses your battery up quickly.
0:36:47 > 0:36:50But if you really want to save battery life,
0:36:50 > 0:36:53then GPS is worth turning off, too.
0:36:55 > 0:36:59Saving battery life is OK, but can only get you so far.
0:37:00 > 0:37:04To stand a chance of powering our phone for a year,
0:37:04 > 0:37:08we're going to need a new battery design.
0:37:09 > 0:37:13So hundreds of research labs around the world,
0:37:13 > 0:37:16including our research lab,
0:37:16 > 0:37:19are searching for the next big battery discovery.
0:37:19 > 0:37:23There are lots of new designs out there,
0:37:23 > 0:37:27and I'd like to tell you about one of the most exciting examples,
0:37:27 > 0:37:31actually theoretically, the best battery.
0:37:31 > 0:37:34Can you please welcome Dr Lee Johnson
0:37:34 > 0:37:37from Peter Bruce's group to operate this battery for me.
0:37:41 > 0:37:42Thank you.
0:37:48 > 0:37:55So this unusual battery uses just lithium metal reacting with oxygen
0:37:55 > 0:37:59from the air. So it's a lithium oxygen battery.
0:37:59 > 0:38:03This makes it very lightweight and very energy dense.
0:38:03 > 0:38:08So what you have here, this is a vacuum chamber and inside it is
0:38:08 > 0:38:10actually the lithium battery cell.
0:38:10 > 0:38:14It's not powering these lights at the moment, OK.
0:38:16 > 0:38:21The battery itself is made up of what we call a chemical sandwich.
0:38:21 > 0:38:24So let me show you what that sandwich looks like.
0:38:24 > 0:38:31Here it is. This is about half a gram of lithium metal, OK.
0:38:31 > 0:38:35And that's within that very cell, only half a gram of lithium metal.
0:38:36 > 0:38:37The other...
0:38:39 > 0:38:43..part of that sandwich is just this kind of carbon mesh.
0:38:45 > 0:38:49And this carbon mesh has a very high surface area,
0:38:49 > 0:38:53and what that allows is the oxygen to react with the metal.
0:38:53 > 0:38:55So if you let the air in,
0:38:55 > 0:38:59we should see hopefully the lights go on from that reaction.
0:38:59 > 0:39:02- Are you ready?- Tell us what you're going to be doing here.
0:39:02 > 0:39:04OK, so there's a vacuum in here. And I'm going to open this valve,
0:39:04 > 0:39:06and that's going to let the air into this chamber.
0:39:06 > 0:39:10And hopefully what you'll see is the pressure go up here,
0:39:10 > 0:39:12and you'll see these lights come on.
0:39:12 > 0:39:13- So, are we ready?- OK.- Yeah.
0:39:13 > 0:39:15OK. So you'll hear a hiss.
0:39:20 > 0:39:23And we should see it start to light up now.
0:39:23 > 0:39:26- OK.- So there you see, you can see it going.
0:39:30 > 0:39:34So this is being produced by this lithium oxygen battery.
0:39:39 > 0:39:42And that was only half a gram of lithium.
0:39:42 > 0:39:46So this stores a high amount of chemical energy,
0:39:46 > 0:39:51at least three times more energy than today's lithium ion batteries
0:39:51 > 0:39:53in your mobile phones.
0:39:53 > 0:39:56So these batteries are exciting.
0:39:56 > 0:39:58They do need more research,
0:39:58 > 0:40:03but they're probably at least a decade away for practical devices
0:40:03 > 0:40:05in your phone.
0:40:05 > 0:40:08So let's thank Dr Lee Johnson again. Thank you.
0:40:17 > 0:40:19So, so far in this lecture,
0:40:19 > 0:40:23we've mostly been looking into how to power our phone for a year.
0:40:25 > 0:40:27I'm going to move away from that for a moment,
0:40:27 > 0:40:31because I want to talk about some other ways energy storage
0:40:31 > 0:40:33affects our lives.
0:40:33 > 0:40:38One important area is the huge growth in renewable energy,
0:40:38 > 0:40:41such as wind and solar.
0:40:42 > 0:40:46Last year, the UK generated a quarter of our electricity
0:40:46 > 0:40:50from renewables - solar, wind and wave power.
0:40:50 > 0:40:55But what happens when the wind isn't blowing and the sun isn't shining?
0:40:55 > 0:40:59So currently, there is no single solution.
0:41:00 > 0:41:04Batteries will play a part, but we need something
0:41:04 > 0:41:06on a much bigger scale.
0:41:07 > 0:41:09There are a number of options.
0:41:09 > 0:41:14People have tried pumping water into raised reservoirs when
0:41:14 > 0:41:19energy's plentiful and releasing it to give us power at a later date.
0:41:19 > 0:41:23This is sometimes called pumped hydro.
0:41:23 > 0:41:26But there's one fascinating form of large-scale energy storage
0:41:26 > 0:41:31I'd like to tell you about. It's called magnetic energy storage.
0:41:32 > 0:41:36This is a strip of powerful magnets.
0:41:36 > 0:41:39So you can see here, it forms this track round here.
0:41:41 > 0:41:45And what we have here is some superconductors
0:41:45 > 0:41:47in that liquid nitrogen.
0:41:47 > 0:41:51These superconductors actually only work at very low temperatures.
0:41:51 > 0:41:55So could you place that on this powerful strip of magnets?
0:41:55 > 0:41:58And let's see it levitating around.
0:42:01 > 0:42:04So let's give it another nudge there. Yes, it goes.
0:42:04 > 0:42:05CROWD MURMURS EXCITEDLY
0:42:05 > 0:42:07Yes. Yes, that's much better.
0:42:10 > 0:42:11There it... Oh!
0:42:13 > 0:42:14Yes!
0:42:18 > 0:42:20Yes.
0:42:20 > 0:42:24A superconductor is a material that shows powerful magnetic behaviour.
0:42:24 > 0:42:29The reason this vehicle floats is because inside the superconductor
0:42:29 > 0:42:34is an electric current that meets no resistance.
0:42:34 > 0:42:36And if you make a ring out of this superconductor,
0:42:36 > 0:42:40it forms a never-ending electrical circuit.
0:42:40 > 0:42:44So this circuit can store large amounts of electricity to be used
0:42:44 > 0:42:47later on. OK, so a round of applause there.
0:43:03 > 0:43:08There's one other crucial area of our lives that better energy storage
0:43:08 > 0:43:11could completely revolutionise -
0:43:11 > 0:43:13the cars we drive.
0:43:13 > 0:43:18We saw that sporty electric car at the beginning of the lecture.
0:43:18 > 0:43:22Thanks to advances in lithium batteries, we're at the dawn
0:43:22 > 0:43:25of the era of the electric car.
0:43:25 > 0:43:29But they've got stiff competition.
0:43:31 > 0:43:35We've seen that a couple of large lithium batteries could power
0:43:35 > 0:43:38the London Eye a quarter turn.
0:43:38 > 0:43:42So what would the same weight of petrol do?
0:43:42 > 0:43:47So that's a quarter of a turn for the lithium ion battery.
0:43:47 > 0:43:51How far would that petrol go?
0:43:51 > 0:43:53So let's have a look.
0:43:53 > 0:43:54It will go
0:43:54 > 0:43:59three revolutions, four, 16, 18, 19, 20.
0:43:59 > 0:44:0320 revolutions of the London Eye.
0:44:03 > 0:44:07It stores more than 50 times the best lithium ion battery.
0:44:07 > 0:44:12So in terms of energy, it's way, way ahead.
0:44:13 > 0:44:17But as I'm sure you'll know, petrol has some serious problems.
0:44:18 > 0:44:21So, a bit of chemistry here, and I am a chemist.
0:44:21 > 0:44:23So, petrol...
0:44:26 > 0:44:30..is made up of long chains of hydrogen and carbon,
0:44:30 > 0:44:33which we call hydrocarbons.
0:44:37 > 0:44:41So these are beautiful
0:44:41 > 0:44:44molecular models of... This is octane.
0:44:44 > 0:44:48So you can see the black are carbons,
0:44:48 > 0:44:51the small white balls are hydrogen.
0:44:51 > 0:44:53But there's a problem.
0:44:54 > 0:44:59When you burn these, you get pure carbon, that black.
0:44:59 > 0:45:02But you also get something else, something you can't see -
0:45:02 > 0:45:03carbon dioxide.
0:45:03 > 0:45:07And that's this feature there,
0:45:07 > 0:45:09so that's carbon dioxide.
0:45:09 > 0:45:10So if you take that.
0:45:11 > 0:45:13So this is carbon dioxide.
0:45:13 > 0:45:16So the carbon has reacted with oxygen,
0:45:16 > 0:45:19so the reds are the oxygens and the carbon is in black.
0:45:19 > 0:45:21But that's just the molecular model.
0:45:23 > 0:45:26We're going to look and see how much energy they produce,
0:45:26 > 0:45:29but also some of the pollution they may produce.
0:45:29 > 0:45:32So we're going to burn just a bit of petrol.
0:45:32 > 0:45:35There's a bit of petrol in that crucible,
0:45:35 > 0:45:38and we're going to see the effect of burning that.
0:45:41 > 0:45:43OK. So there's some petrol burning.
0:45:44 > 0:45:49And what happens when you just put a simple tile over it?
0:45:54 > 0:45:56Obviously do not do this at home.
0:45:56 > 0:46:02And you can see very quickly how much carbon soot's been produced.
0:46:04 > 0:46:05OK.
0:46:07 > 0:46:09Thanks. Thanks, Natasha.
0:46:10 > 0:46:14So that's the problem with today's cars -
0:46:14 > 0:46:18petrol-powered road transport produces a lot of air pollution,
0:46:18 > 0:46:22and going electric would be much better for air quality,
0:46:22 > 0:46:23and better for the planet.
0:46:23 > 0:46:27But first we need to solve a big issue with electric cars -
0:46:27 > 0:46:31can we go a long distance without charging?
0:46:31 > 0:46:34Some people call this range anxiety.
0:46:35 > 0:46:40Did you know, though, that most car journeys in the UK are less
0:46:40 > 0:46:44than 30 miles? But obviously it's nice to know that we can go further
0:46:44 > 0:46:46if we need to.
0:46:46 > 0:46:51And I've always wanted to celebrate New Year in Scotland,
0:46:51 > 0:46:55so I wanted to find out if I could drive an electric car from
0:46:55 > 0:46:57the Royal Institution here
0:46:57 > 0:47:00to Edinburgh on one charge.
0:47:01 > 0:47:04So we can see here,
0:47:04 > 0:47:07hopefully you can, if you're not geographically challenged,
0:47:07 > 0:47:09that here is London.
0:47:09 > 0:47:12And to get to Edinburgh, you'd follow the A1
0:47:12 > 0:47:15right up this path here.
0:47:16 > 0:47:21So we want to look at different types of electric vehicle
0:47:21 > 0:47:22and see how far we could go.
0:47:22 > 0:47:25So I need a volunteer to help with this.
0:47:25 > 0:47:28So I should get somebody from there, do you want to come down?
0:47:28 > 0:47:29Great.
0:47:34 > 0:47:35OK. So can I take your name?
0:47:35 > 0:47:39- Sam.- Sam, good. Could you come on this side here?
0:47:39 > 0:47:43So we've got some different vehicles and I'm going to pass them to you.
0:47:43 > 0:47:50Right, so first of all, we've got an electric golf cart.
0:47:50 > 0:47:54OK. So what I'd like you to do, you're going to start there.
0:47:54 > 0:47:58If you could just gently go up the A1 and when you feel a bit of
0:47:58 > 0:48:01magnetic pull, just stop there, OK.
0:48:01 > 0:48:03Let's go along there. Yes.
0:48:03 > 0:48:06So the second vehicle, the G-Wiz.
0:48:08 > 0:48:10Right. That's a G-Wiz vehicle,
0:48:10 > 0:48:12that electric vehicle.
0:48:12 > 0:48:16Right. See if you can actually feel some magnetic tension again.
0:48:16 > 0:48:18There. Does it feel there? Yeah.
0:48:18 > 0:48:21That's it. Actually, it doesn't go much further.
0:48:21 > 0:48:25That G-Wiz car goes only about 50 miles outside London.
0:48:25 > 0:48:27So let's go to the third vehicle.
0:48:28 > 0:48:29And this is...
0:48:31 > 0:48:34..a Nissan Leaf. This is an all-electric Nissan Leaf.
0:48:34 > 0:48:35So if you can go along the A1.
0:48:36 > 0:48:41About there. So that's actually about 124 miles outside London.
0:48:41 > 0:48:46OK. So there are some actual London buses that are electric powered.
0:48:46 > 0:48:47OK, let's have a go.
0:48:47 > 0:48:51Let's do up from there and let's see how far you can get.
0:48:52 > 0:48:54Is it feeling...? Around there. That's a good one.
0:48:54 > 0:48:56So that is about 180 miles,
0:48:56 > 0:48:58just a bit further than the Nissan Leaf.
0:48:58 > 0:49:03The last one, this is the latest Tesla Model S.
0:49:03 > 0:49:07OK. And let's see how far that goes.
0:49:07 > 0:49:10So you can start from the London bus, let's see.
0:49:10 > 0:49:11Gently go up there.
0:49:11 > 0:49:14About there. It doesn't quite get to Edinburgh.
0:49:14 > 0:49:19In fact, it's gone just over 300 miles from London.
0:49:19 > 0:49:21So thank you again. Thank you.
0:49:21 > 0:49:22Thank you.
0:49:26 > 0:49:31So as we've seen, I'm not going to get to Edinburgh on one charge.
0:49:31 > 0:49:35Petrol cars still have the edge on range.
0:49:35 > 0:49:40But batteries are improving, thanks to worldwide research efforts.
0:49:40 > 0:49:43So one way electric cars are seriously competing
0:49:43 > 0:49:45is in performance.
0:49:45 > 0:49:50And if you love fast cars like that sporty electric car I arrived in,
0:49:50 > 0:49:53going electric might not be as bad as you think.
0:49:53 > 0:50:00I asked the 2014 Christmas Lecturer, Professor Danielle George,
0:50:00 > 0:50:02to put this to the test.
0:50:02 > 0:50:04Hi, Saiful. Hi, everyone.
0:50:04 > 0:50:09I'm here at a closed-off racetrack with two very exciting cars.
0:50:09 > 0:50:12One of them is a petrol-powered supercar,
0:50:12 > 0:50:14the Bentley Continental Titan,
0:50:14 > 0:50:17which has been souped-up to within an inch of its life.
0:50:17 > 0:50:21The other is an electric car, the Tesla Model S,
0:50:21 > 0:50:23which looks a bit like a posh saloon.
0:50:23 > 0:50:26But I'm going to be putting these two cars to the test to see
0:50:26 > 0:50:29which one reaches 60mph the quickest.
0:50:33 > 0:50:34Very, very exciting.
0:50:46 > 0:50:47Three...
0:50:47 > 0:50:48ENGINE REVS
0:50:48 > 0:50:50Two, one.
0:50:50 > 0:50:51HORN BLOWS
0:50:51 > 0:50:53Wow!
0:50:53 > 0:50:54Oh, my Lord!
0:51:03 > 0:51:04Good grief!
0:51:06 > 0:51:09That is amazing!
0:51:09 > 0:51:11Oh. I'm still shaking!
0:51:14 > 0:51:18It is seriously like being on some sort of roller-coaster.
0:51:18 > 0:51:20It is so fast, and so quiet.
0:51:23 > 0:51:28And I definitely left the Bentley Continental for dust.
0:51:28 > 0:51:32Now, an all-electric car similar to this actually holds the record
0:51:32 > 0:51:36for the fastest 0-60 time, and there's a reason for that.
0:51:37 > 0:51:40A petrol car uses gears,
0:51:40 > 0:51:42and so as we increase our speed,
0:51:42 > 0:51:44we need to increase the gear that we're using.
0:51:44 > 0:51:46And you can really see this on this graph here.
0:51:46 > 0:51:50So what we have are both cars plotted here, time and speed.
0:51:50 > 0:51:54The red is the electric car, and the black is the petrol car.
0:51:54 > 0:51:59And you can see the speed and then the gear change here,
0:51:59 > 0:52:02and then the increase in speed again after the gear has changed.
0:52:02 > 0:52:04But with an all electric car,
0:52:04 > 0:52:08we get peak performance from that electric motor as soon as our foot
0:52:08 > 0:52:11hits that pedal. So there's no need for gears.
0:52:12 > 0:52:17And the result is one mean, green speed machine.
0:52:17 > 0:52:20And this is all possible thanks to better batteries.
0:52:21 > 0:52:22Yes.
0:52:31 > 0:52:35Thank you, Danielle. I think we'll be seeing a lot more electric cars
0:52:35 > 0:52:38on our roads in the future, but maybe not going as fast
0:52:38 > 0:52:41as that one, obviously.
0:52:41 > 0:52:44For the moment, we're still stuck on petrol.
0:52:44 > 0:52:48Is there anything that can beat it in terms of energy density?
0:52:48 > 0:52:52Here are our lithium and potassium atoms from earlier.
0:52:52 > 0:52:58And this is... I think it's nice to use a couple of volunteers.
0:52:58 > 0:53:00If you hold on to those.
0:53:00 > 0:53:04So I showed you... Just remind you, that's potassium and that's lithium,
0:53:04 > 0:53:06and just to show their relative sizes.
0:53:06 > 0:53:10Obviously, that's not the real size of their atoms.
0:53:10 > 0:53:14But there's an even smaller atom we can use.
0:53:15 > 0:53:16Hydrogen.
0:53:16 > 0:53:18Just a single proton.
0:53:18 > 0:53:23So I might as well put it right there, so if you just hold that.
0:53:23 > 0:53:25So if you see the relative sizes,
0:53:25 > 0:53:27this is to scale.
0:53:27 > 0:53:31Hydrogen is five times smaller than lithium.
0:53:31 > 0:53:34In fact, hydrogen is the smallest and lightest element
0:53:34 > 0:53:36in the periodic table.
0:53:36 > 0:53:41By weight, hydrogen is the most energy-dense fuel.
0:53:41 > 0:53:46I think it's London Eye time again, to see how they compare.
0:53:46 > 0:53:47So if you remember...
0:53:50 > 0:53:56..30kg of lithium battery turned it a quarter, OK.
0:53:56 > 0:53:59The same weight of petrol turned it...
0:54:00 > 0:54:02..20 times.
0:54:02 > 0:54:07This is the same weight of hydrogen fuel as a liquid.
0:54:07 > 0:54:08Let's have a look.
0:54:10 > 0:54:15Starts off 20, past 30, past 40.
0:54:15 > 0:54:1862 revolutions.
0:54:18 > 0:54:22It would power it for three whole days.
0:54:22 > 0:54:27There's no doubt hydrogen contains a huge amount of energy,
0:54:27 > 0:54:31and I can show you this with another simple demonstration -
0:54:31 > 0:54:34a balloon full of hydrogen.
0:54:36 > 0:54:40But this demo needs hands over your ears.
0:54:43 > 0:54:44OK.
0:54:49 > 0:54:52Whoa! Go on, yes!
0:54:52 > 0:54:53Yes!
0:54:57 > 0:55:02Right, so can we harness the energy from this powerful chemical reaction
0:55:02 > 0:55:03more efficiently?
0:55:04 > 0:55:06Yes, we can.
0:55:06 > 0:55:09Hydrogen is used in things called fuel cells,
0:55:09 > 0:55:12that are actually being used to power several London buses
0:55:12 > 0:55:16right now. So can I use this super fuel to power my phone?
0:55:17 > 0:55:22OK. This is a commercial fuel cell, it's a tiny one,
0:55:22 > 0:55:24but you can't quite see inside it.
0:55:24 > 0:55:28So we've got a demonstration fuel cell to show how it works
0:55:28 > 0:55:31in this Perspex device here.
0:55:31 > 0:55:34So what we have here is the oxygen
0:55:34 > 0:55:38and the hydrogen. If they react within this fuel cell,
0:55:38 > 0:55:39they can produce energy.
0:55:39 > 0:55:42Now that can be shown easily by this fan here.
0:55:44 > 0:55:45There you are.
0:55:50 > 0:55:52A fuel cell is very similar to a battery -
0:55:52 > 0:55:55it has two electrodes and an electrolyte.
0:55:55 > 0:55:57But there's a big, big difference -
0:55:57 > 0:56:00the battery is self-contained.
0:56:00 > 0:56:04A fuel cell needs to be fed with hydrogen as a fuel.
0:56:04 > 0:56:08So let me drink a typical fuel cell by-product.
0:56:13 > 0:56:14It's just water.
0:56:14 > 0:56:16So you can't get any cleaner than that.
0:56:18 > 0:56:21But can it power my phone?
0:56:21 > 0:56:25Shall we plug our phone into our working fuel cell?
0:56:25 > 0:56:30OK, so this is a typical phone.
0:56:30 > 0:56:32So let's turn on the device.
0:56:35 > 0:56:38Hopefully you can now see the charging.
0:56:38 > 0:56:43So this could power our phone for a whole year without plugging
0:56:43 > 0:56:48in to the mains, but we still need to top it up with hydrogen.
0:56:48 > 0:56:53Sadly, hydrogen is not the answer to all our energy problems, not yet.
0:56:53 > 0:56:58We have to store it at a temperature of minus 250 degrees Celsius
0:56:58 > 0:57:00to keep it a liquid.
0:57:00 > 0:57:03This means that hydrogen is costly to store,
0:57:03 > 0:57:08takes a lot of energy to produce, and has safety issues.
0:57:08 > 0:57:12Finding better ways to store energy is still a vital challenge.
0:57:14 > 0:57:15In these lectures,
0:57:15 > 0:57:18we've celebrated the 80th anniversary
0:57:18 > 0:57:20with Christmas lecturers past.
0:57:20 > 0:57:23We've celebrated energy in all its different forms,
0:57:23 > 0:57:27and broken a world record.
0:57:27 > 0:57:31I've got one final energetic celebration -
0:57:31 > 0:57:33I want to go out with a big bang.
0:57:33 > 0:57:36Hands over your ears, and goggles on!
0:58:00 > 0:58:04We're at the dawn of a new era in clean energy.
0:58:04 > 0:58:09The next chapter of fuelling the future is for all of you to write.
0:58:09 > 0:58:12So go out and charge ahead.
0:58:12 > 0:58:13Thank you, and good night!
0:58:16 > 0:58:17Thank you.