Battery technology has changed little since Volta, but are longer lasting batteries finally here?

The discussion above was broadcast on Today with Sean O’Rourke on 14th September, 2015

Volta's Battery

Battery technology has changed little since Alessandro Volta’s stacked battery of 1799, here being demonstrated above to Napoleon. But, a technological breakthrough may finally be on the way (Source: Jean Loup Charmet/ Science Photo Library)

We take batteries for granted, but it is hard to imagine a world without them. Think about it for a moment. Almost everything that requires power, makes use of battery power.

The list includes cars (electrical and fuel powered), children’s toys, bicycle lights, recording devices, hearing aids, and, of course, our beloved laptops, tablets and smartphones.

Batteries have, however, become a limiting technology, and for years have been acting like a brake on the development of ever faster, more powerful electronic devices and gadgets.

Whereas, the power of a microchip – the brain of our electronic devices – has doubled every two years or so, since the 1970s, battery power, upon which they rely, hasn’t kept pace.

While the microchip has been doubling its power relentlessly every couple of years, engineers have struggled to get an extra 30 per cent of power from batteries over the same time frame.

The remarkable thing is that until recently, the technology upon which batteries are based hadn’t changed much since the first working battery designed by Alessandro Volta in 1799.

Yet there are many new technologies in development which could provide the long sought breakthrough that would provide us – at last – with batteries that can provide power at a high enough level and long enough to suit our needs.

History

In 1791 Luigi Galvani noticed that an electrical circuit created with two different metals, when touched on two ends of the leg of a dead frog, would cause the frog’s leg to twitch.

The two metals were creating an electric current within the frog’s leg, causing its muscles to contract. This was a transfer of chemical energy into electrical energy – a primitive battery.

The first simple, working battery, as we would recognise it today, which became known as the Voltaic pile, was built by Alessandro Volta, an Italian physicist in 1799.

Volta’s battery was not the first device created by humans which could produce electricity, as the famous ‘Baghdad Battery’ dates back to about 200 BC.

These batteries were discovered by an archaeologist called Wilhelm Konig, outside Baghdad in 1938. They were small jars, which held an iron rod contained in copper.

Tests on the batteries indicated that the jars had been filled with some kind of acidic substance like vinegar or wine, leading researchers to theorise that they were ancient batteries.

However, the Volta battery was the first to produce a steady, lasting electrical current.

Volta’s battery had two electrodes. An electrode, to explain, is something which exists to create a connection between an electric conductor and a non electrical conductor.

So, a lamp that is connected to a battery would be connected by an electrode, which would carry the electrical current from the battery, to the lamp, via safe, non conduction materials.

The electrodes in the Volta battery were circular disks of zinc metal and copper metal, separated by cardboard paper in between them, which was soaked in salty water.

An electrolyte is something either liquid, or molten, which is full of ions, or negatively charged atoms, which are the basic building blocks of electricity. Volta’s electrolyte was salty water.

Chemical reactions in the electrolyte led to a positive charge being created at the zinc electrode – the anode – and a negative charge created at the copper end – the cathode.

The electricity in battery flows from towards the positive cathode, because electricity by its nature is negatively charge, and in Volta’s battery this flow could not be reversed.

One problem with Volta’s battery was there was a buildup of hydrogen gas, a by-product of the chemical reactions,which formed a barrier between the electrolyte and the electrodes.

Thus, the effectiveness of the Volta battery diminished over time. Furthermore, when more acidic electrolytes came into use, batteries could often be dangerous to handle.

Another problem was that because the Volta battery was built in a stack, the weight of the stack would, after a certain height, begin to squeeze the brine out of the cardboard.

Model T Ford

The 1926 Model T Ford, pictured here, was the first mass produced car to have an automatic starting key. This was possible by using a battery designed by Irish priest Fr Nicholas Callan in 1837 (Credit: automotivehistoryonline.com)

Fr Callan’s Battery

One of the key researchers in what scientific historians call ‘the electric century’ – the 19th century – when electricity was harnessed and made widely available – was an Irish priest.

Fr Nicholas Callan was a 19th century battery pioneer and Catholic priest, based at at what was then part of The Catholic University of Ireland (now called Maynooth University).

He built some of the most powerful batteries and magnets that had ever been built in his workshop at Maynooth, and he spent long hours there, immersed in his researchers.

Callan, unlike scientists today, did not publish his findings, but when he had mastered some aspect of knowledge, he simply moved on to the next topic that he was interested in.

This meant that he did not get credit for the extent of his contribution to the development of the battery, and to the widespread availability of electricity until relatively recent times.

One of his inventions, called the induction coil, was a quantum leap for battery technology when he invented it in 1837. It was the first immensely powerful battery ever invented.

Our modern cars can be started by a simple turn of a key, thanks to a battery designed by Irish priest in the 19th century, and put into a Model T Ford in 1926.

Up until the 1920s, cars had to be started by manually by turning a hand crank. This was physically demanding, and people that were not young and fit often couldn’t manage it.

Callan developed an induction coil in 1837, almost a century before, which provided a way to massively ramp up the electrical power available to a small Model T car battery.

The 1926 Model T Ford, was the first car that went into mass production with an electrical starting mechanism, and this meant anyone, regardless of age or health, could drive a car.

The technical trick that Callan uncovered was to repeatedly break the electrical circuit in a battery by dipping copper wires in liquid mercury cups.

Callan found that the more rapidly he could break the current, using his ‘repeater’, the more intense the flow of electricity produced would become.

He was a quiet intense man, who spent hours in his laboratory at what is now NUI Maynooth. HIs fellow clerics wondered at his interest in science, and regard his lab work as useless.

Daniell Cell

Around the same time Fr Callan was working, in the 1830s, a British scientist John Daniell, developed an improved version of Volta’s battery which was called the Daniell cell.

The so-called Daniell Cell was made up of two metal plates, one of copper and one of zinc, and two solutions, of copper sulfate and zinc sulfate, all in a simple glass jar.

Copper sulfate is denser than zinc sulfate so it sank to the bottom of the glass jar and surrounded a copper plate. The lighter zinc sulfate floated on top of the copper sulfate and it was surrounded by a zinc plate. The zinc plate was negative and the copper the positive.

This worked well for stationary applications, such as powering doorbells, and early telephones, but it didn’t work for mobile applications such as powering a flashlight. But, it worked.

Chemistry

The principles of what happens when you put a battery into your remote control or flashlight today, in September 2015, is similar to the early batteries, going back more than 200 years.

Basically, chemistry is being used to generate electricity, and move it from one part of the battery to the other, and then into the device where the electrical power is consumed.

In simplest terms, the chemical reactions in the anode, or negative end of the battery, creates electrons, which are the basic units of electricity.

These electrons are transferred in the electrolyte substance, which is liquid of some sort, often an acid, from the anode, to the positive end of the battery, the cathode, via a current.

At the cathode chemical reactions occur which essential absorb the electrons, and their energy, to produce electricity, which is transferred to a device running on battery power.

The battery will continue to produce electricity until one, or both, of the electrodes, run out of the substances which are needed to produce and absorb electricity respectively.

Modern batteries are still based on using chemistry to produce, absorb and transfer electricity. We have got better – somewhat – at manipulating the chemistry to make better batteries.

There are zinc-carbon batteries, alkaline batteries, lithium ion batteries and lead-acid batteries in common usage today.

The lead-acid battery, which is used in a typical car battery has electrodes made of lead oxide and metallic lead, while the electrolyte is a sulfuric acid solution.

These are dangerous to handle, and an environmental nightmare, but they produce enough electricity to get a car started in the morning, and that is what we all ultimately want.

The alkaline batteries, are the kinds of batteries we buy in shops, to put into children’s toys, for example. The cathode here is a manganese dioxide mixture, and the anode a zinc powder.

It gets its name, however, from its potassium hydroxide electrolyte, an alkaline substance..

Acids are often excellent electrolytes, because they strongly ionize in solution. They can produce a lot of ions when put into solution, whether they are positive or negative.

ither way, acids don’t form stable molecules when put in solution. The create ions, which are highly mobile in solution, and facilitate the conduction of electricity.

Rechargeable batteries

In the modern era it has become important to develop decent rechargeable batteries, such as mobile phone charges, which can be plugged in and recharged on the move.

However, rechargeable batteries have been around a long time. In fact they date back as far as 1859 when Gaston Plante, a French physicist invented the humble lead acid battery.

We know that lead acid batteries in our cars can run out, hence the jump leads we carry in the boot. The jump leads are used to re-charge the battery from another battery usually.

The difference between a rechargeable battery and a non-rechargeable one is that the chemical reactions producing electric current in a rechargeable battery are reversible.

As the world, a became increasingly mobile, it was vital to invent a powerful, rechargeable battery. Along came the lithium-ion battery in 1991 (by Sony and Asahi Kasei)

In this battery, charge could be reversed, and the products that were in the battery were not going to be used up rapidly, or diminished in power with multiple weekly charges.

The lithium-ion battery, which goes into so many of our devices, is one such rechargeable battery. These are high performance batteries, which often used lithium cobalt oxide as the cathode and carbon as its anode. These materials, lithium, and carbon, are also very light.

owever, lithium ion batteries still need an electrolyte, typically lithium salt, which is in solution. So, these high technology batteries are still limited by the need for a liquid solution.

The future

There are many competing technologies working to develop the breakthrough that will move batteries on to the next stage.

There are solid state batteries, and solar batteries, and even batteries, which scientists have recently proposed, which could be based on thin air?

Solid state batteries will be made of solid electrodes and solid electrolytes. They can be easily miniaturised, and long shelf lives. They also are not prone to reduced performance due to temperature like liquid electrolytes, when exposed to near freezing or boiling conditions.

The technical problem with solid state batteries, however, is that it is proving difficult for engineers to get high electrical currents moving easily across solid to solid surfaces.

Solar batteries are another technology being explored, as the next big thing in batteries, and these are based on converting the energy in sunlight directly into electrical energy.

The materials used are those that change their electrical characteristics in response to sunlight. They work in a similar way to solar panels, but they need to be smaller of course.

Wind batteries 

Tesla Motors, from the US, meanwhile, are developing industrial scale batteries, which can be used to power the home, they say, or to store energy from renewable sources like wind.

In May Tesla and an Irish company Gaelectric announced they were going to work on a large utility scale battery power project in Ireland.

The plan is to demonstrate that Tesla batteries, can store energy from the sun and the wind, which there is plenty of in Ireland, and release in quantities sufficient for utilities to use.

Tesla also wants to enable business and homes to be able to store renewable energy from the Sun, and wind to manage their power needs, and reduce reliance on fossil fuels.

However, when it comes to our electronic devices, it seems that a workable solar battery, which is powerful and cheap, and reliable is still no-where in sight.

Solar powered batteries can be sluggish on start-up when they are cold, and they don’t have enough power, of the type that an iPhone requires, for example to do the job.

Their role maybe to have a solar battery on the iPhone as a back-up to use in an emergency when the battery is running low and there is no electrical socket in sight.

Hydrogen

Future iPhones could run on hydrogen refuelled via the headphone socket. Intelligent Energy, a British firm behind the breakthrough, expects there’ll be a gas cartridge slot (Credit: iFixit)

Intelligent Energy says it made an iPhone 6 with a battery which creates electricity by combining hydrogen and oxygen – that means air! – to last the phone for a week.

The bonus is that the combination of hydrogen and oxygen, produces only small amount of water and heat as waste products.

This announcement has been shrouded in secrecy as it correct this will be a massive breakthrough. The company said its fuel cell system was incorporated into the current iPhone 6 without any alteration to the size or shape of the device.

The only difference, compared to other handsets is that there are rear vents where a tiny amount of water vapour waste is allowed to escape.

Intelligent Energy, who are reportedly working closely with Apple, said they are considering what price to sell their cartridges at, so it’s not going to be part of the iPhone per se.

It’s likely the cartridge might sell for just the cost of a latte, company executives said, and even so, a 300 billion Sterling market per year could open up.

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