It is a truth universally acknowledged that when Sir Isaac Newton was sitting in his English garden one day, an apple fell on his head. As he recovered from the blow, he saw the light – or lights – and discovered gravity. Had he, perhaps, been sitting in his garden in, say, Indonesia or the Philippines under a coconut palm, then it seems likely that nobody would have ever heard of it, or of him for that matter. By such coincidences does science proceed. 

He called the phenomenon ‘gravity’ after the Latin virtue ‘gravitas’ which was one of the great Roman virtues meaning seriousness, dignity, responsibility and, of course weight. Gravity is serious stuff. So what could be better than to name the simplest of all batteries after the great man himself; the Newton Battery. This uses the mighty power of gravity to generate electricity by allowing lumps of concrete or bricks to fall down, while attached by wire to turn a generator. Of course, you need to pull them up before you do this using excess electricity from solar or wind, but the aim of the game is to get the power when you actually need it. The fact that you get roughly 75% of the electricity out of it that you put into it in the first place to pull the concrete up, is neither here nor there.

This is perhaps an unfair description, since very large scale ‘batteries’ of this kind have been necessary for the proper operation of electricity grids for decades, even in that ancient era of hydrocarbon-generated power. Two spectacular ones are the Tennessee Valley Authority’s Raccoon Mountain, and Dinorwig in Wales. These both pump water up a mountain and then release it down a shaft to turbines below, thus providing 1,653 MW and 1,800 MW of capacity respectively when it is actually needed to balance the grid. In the case of Raccoon, it takes 28 hours to fill and 22 hours to discharge. Regrettably, such pump storage schemes are both expensive, and lengthy to build and are the product of the 1970s. What is perhaps odd is that, while the UK National Grid believes that a further 10 GWs of these will be needed to balance the renewable grid by 2030, new ones in Scotland and elsewhere are stuck in limbo by the “contract for differences” payment scheme.

But to return to the Newton Battery, kings of the game are currently Energy Vault Holdings; a Swiss-American company. Their Battery Energy Storage System (BESS) can punt out power over a few hours, by what they call “the elevator gain of brick”. The machines look like large rectangular boxes, the inside of which have rows and rows of 30 tonne bricks moving up and down on vertical tracks. Given the sheer simplicity of the system – physical not chemical – it   is not a surprise the company now has contracts in Switzerland, USA, India and a 25 MW machine in Rudong, China for a grand total of 1,635 MW of battery power. It may not make everybody as rich as they claim, but revenues of $146 million in 2022 after a company start up in late 2018 isn’t bad going.

Of course, anybody born in the 1950s will not recognise this idea of a battery. For them, a battery will always remain a flat blue cardboard-sided thing with two copper conductors, which if you left it too long in your bicycle light would corrode the inside. The dynamo was a great advance. One has to suspect that for many of the elderly the idea of trusting your life to a ‘battery’ is a technology too far, although many in fact now do so in pacemakers. Or alternatively a battery is seen as two small round tubes, which are too fiddly to recharge when they fade, or the heavy old lead-acid cuboid that provides the spark that ignites the petrol in a car. Sure, they are rechargeable, but they do need refilling with distilled water. But the idea of driving around for miles on electricity would be absurd.

Yet batteries have clearly moved on since they were first invented in around 1800 by the Italian Volta. He put copper and zinc in diluted sulphuric acid and the zinc oxidised causing electrons to flow to the copper and it also produced hydrogen. There were several disadvantages to this, for not only was the acid corrosive, but the resulting hydrogen could explode. That said, the invention did set off a fascination with electricity which made a great many advances in the science, if nothing much as yet, of practical value. In the 1840s, for example, James Joule wanted to run his father’s brewery on electricity, produced from zinc and acid, and discovered that a pound of zinc in acid could lift over 300,000 pounds, but sadly only by one foot. Steam from coal was a lot cheaper than zinc for a start.

What was needed was to go down the list of standard electrode potentials in so far as they knew what they were and mix and match them and this duly happened. Gaston Plante did the lead-acid mix in 1859 and this helps drive our cars even today. One of the first dry cells hit the streets using zinc-carbon arrived in 1881, while the first rechargeable – nickel-cadmium – came in 1899. Edison started using alkaline storage in 1901. Eveready got its name in 1905 and in 1949 produced Alkaline-Manganese batteries, which lasted at least five times as long as its rivals. Duracell came along in 1924.

While not diminishing the achievements involved in any of this, none of it would be capable of running a car very far. The battery which does this – the lithium-ion battery – had to wait until the 1970s and was really the work of three men; Stanley Whittingham, John Goodenough and Akiro Yoshino, who all won the Nobel Prize for Chemistry in 2019. Respectively Anglo-American, American and Japanese, the two former scientists got their doctorates from New College, ironically one of the oldest colleges in Oxford, while Whittingham worked for 15 years for Exxon and it was in their New Jersey labs that he produced the first one.

The advantage of lithium-ion as a battery is that it has a very high energy density in that it has a lot of power in a very small space. Equally, it has relatively low self-discharge and does not run down over time without connection. Finally, unlike Nickel-Cadmium rechargeables, it does not hold much less energy after it has been recharged several times, known as the ‘memory effect’. The anode is made with graphite, the cathode with a metal oxide and the electrolyte is a lithium salt in a solvent.

Or at least it was. What the three pioneers started was a whole variety of experiments with materials for anodes, cathodes and electrolytes from titanium, nickel, cobalt, manganese, iron, silicon, tin and carbon all using lithium as the core. Much naturally depends upon cost, which in the case of lithium has risen exponential from $20,000 to $88,000 a ton since 2017, as a result of its use in batteries, only falling back marginally due to covid. Areas of production include, China, Australia, Chile and Argentina.

In fact, if truth were told, it would have been much better if Whittingham had discovered some other material with which to make his battery. Of course it is not his fault, but lithium is a horrible little metal. It does not occur in nature in a pure form and must be kept in, say, kerosene, on which it floats, to avoid a reaction with air. Before batteries, one of its principal uses was in thermonuclear explosions. Either way, while most batteries are safe, some of them have the unwelcome habit of catching fire. A famous example was in Samsung’s highly lauded Galaxy 7 mobile phone. Launched in August 2016 with such success that they could not meet demand, the company had to recall them in September because of reports of numerous fires. Changing the batteries produced no improvement and the company had to send out instructions to owners as to how they should be safely returned in boxes.

The airlines have now joined in. Smartphones, tablets, cameras, laptops, vape devices and anything with a lithium-ion or lithium metal battery has to be taken on board with the hand luggage. This is unsurprising and increasingly necessary because of the growth in these batteries. In early 2023, the US Federal Aviation Authority reported that there had been 62 reported incidents of fires on planes due to the batteries in 2022. In 2014 there had been a mere nine. Meanwhile, the New York fire authorities said that lithium-ion batteries had caused over 200 city fires, killing six people and injuring over 150.

In February 2022, the specialised car carrier Felicity Ace caught fire and eventually sank, taking 4,000 cars to the bottom with it and costing Mitsui OSK over $500 million. Many were luxury vehicles, notably Bentleys, Porsches and the last Lamborghini Aventadors ever made. The crew blamed the fire on vehicle batteries and some shipping companies are now refusing to carry them. Attempts at salvage were prevented even after the fire appeared to have gone out, due to the extreme heat. The wreck is now in 10,000 ft of water.

London is not immune from the impact. Electric bikes and scooters are seen as a particular worry. According to the London Fire Brigade, 2022 saw 88 fires in a huge increase over the previous year. The odd thing is that such bikes are illegal on public streets in the UK, but nobody takes much notice, with the result that they are less than properly regulated. What impresses the fire service is the sheer heat and ferocity of the fires produced. Leaving your scooter in a corridor, near the door, will prevent you leaving the building if it burns. Accidents generally with scooters rose by a third in 2022, with 1,437 injured.

This has naturally produced a lot of warnings about counterfeit cells going cheap. This is a more serious problem than it might seem. As the market for lithium-ion cells increases and costs go up, the temptation to cut corners becomes obvious. As the leaders of safety analysis on this kind the thing, the US-based Underwriter’s Laboratories have pointed out that the batteries should have both a positive temperature coefficient and a current interruption device. The problem is that it is very difficult to tell whether these are actually present. They point out that a spelling mistake on the outside wrapper as to its origin in ‘Colifornia’ can be a pretty good guide, but who decides to look? The chances are that the power of the battery is also exaggerated, but the obvious problem is that it could catch fire. Equally, the counterfeit could be a used one and been overcharged repeatedly, which is also dangerous.

One of the oddities in all this is that the International Energy Agency (IEA) has already concluded that the world could face a significant shortage of lithium by 2025. The numbers are certainly not encouraging, as the World Economic Forum agrees. It takes roughly 4-8 kg of lithium to make an electric car battery and in 2022, 10.6 million EVs were sold in a 60% increase over the previous year. That makes 84,800 tonnes of lithium on cars alone. Total global production of lithium was 130,000 tonnes in 2022. If the sales continue at the current rate, EVs could comfortably exceed this requirement as soon as this year.

An equal concern lies in how long they actually last and whether these cars will have a viable second-hand market. This obviously depends on the use of the car. Tesla and Hyundai offer an eight-year warranty, which is good because the batteries are extremely expensive to replace.  Clearly this limit of 100,000 to 150,000 miles in the rest of the warranty is hardly on a par with the more elderly petrol-driven models. Equally if the second-hand market moves into electrics in a big way, the demand for lithium could grow even faster.

The geopolitics of this are not encouraging. China currently has around 60-70% of the lithium output, but around 70-80% of the processing capacity. Consequently, an escalation of conflict with China over Taiwan would not help the immediate future of the electric vehicle. It is not as if lithium is scarce on the planet. As noted, Argentina, Australia and Chile have huge reserves. What matters is both its extraction – hopefully from clay – and its processing, which is expensive. Predictably, Elon Musk is investing in both to keep the show on the road.

This suggests that in the ‘immediate’ future the increase in electric cars and the general use of lithium in batteries may be at risk in the mid years of 2020-2030, but this is by no means the end of the story. The race is on to find safer alternatives, using a collection of alternatives to lithium in the lab. Graphene, the wonderfully robust and high conducting carbon is hardly in the picture yet. To replace gasoline and diesel and head for a net zero economy, as the World Economic Forum calculates, we will need 2 billion electric vehicles by 2050.

What is however significant is that in one lifetime of 70 odd years, the ‘battery’ has evolved from something that spread a hazy light from a bicycle lamp, to something as big as the 110 tonne E-Dumper truck, courtesy of the Swiss company Kuhn Schweiz with a 600 kWh battery that uses regenerative breaking to sustain its charge. Whatever else it has done, the fear of climate change has put a pretty big charge under the backsides of our engineers and scientists.