Tesla CEO Elon Musk doesn’t shy away from grand visions. When he kicked off his highly anticipated “Battery Day” on Tuesday, he began with an early September photo of San Francisco bathed in the orange light of the surrounding wildfires followed by a chart showing the Earth’s skyrocketing temperature.
He then spoke of the need to save the world – and of the solution he already has at the ready: new batteries. “Roughly 20 to 25 terawatt hours” of battery production each year “sustained for 15 to 25 years (is necessary) to transition the world to renewable,” Musk said. That is more than 100 times present-day production capacity. Who, then, is going to deliver the needed technology? Musk, of course!
“We’re putting so much effort into making cells and kind of trying to reinvent every aspect of cell production, from mining the ore to a complete battery pack,” he told his audience on Tuesday. He was speaking at the Tesla factory in Fremont, California, together with his chief engineer Drew Baglino. The two of them came in matching black jeans and T-shirts and, to ensure appropriate social distancing, held their presentation outdoors before just 200 select Tesla stockholders, all of whom remained in their cars. Instead of clapping in approval, they honked their horns.
The article you are reading originally appeared in German in issue 40/2020 (September 26, 2020) of DER SPIEGEL.
The drive-in show in Fremont was intended to send a clear message: Tesla is right at the front of the global race to build the “super battery.” Still, the company’s stock price dropped slightly as a result of the event, with many investors having expected a much more spectacular announcement.
Nevertheless, with the technologies and battery factories that Musk has announced, Tesla has become a serious competitor to the companies from China, Japan and South Korea that have dominated the battery industry until now.
The company that first develops a battery that can be charged quickly, has high energy density and a lifetime spanning millions of miles will likely be rewarded with a significant chunk of what will be a multibillion-dollar market. Indeed, battery companies of today are like the oil companies of old. And the technological leaders control the entire supply chain, from raw materials to the battery itself – perhaps even including the electric car in which it is installed.
The Search for the Perfect Battery
The electric vehicle and car battery industries are important elements in the ongoing power struggle between the U.S. and China. And despite Tesla’s pioneering role, U.S. President Donald Trump’s America has thus far been losing that part of the race. The International Energy Agency forecasts that by 2030, only around 8 percent of newly registered vehicles in the U.S. will be electric, compared to 28 percent in China and 26 percent in Europe. China’s automobile market has been the largest in the world for several years now and the country controls over 70 percent of the globe’s battery production capacity. The Chinese are in a perfect position to profit from the electrification of transportation.
Trucks, buses and perhaps even short-haul passenger jets could all ultimately be propelled by electricity in the dawning, post fossil-fuel age. In 2019, more than 4.5 million electric cars navigated the roads of the world. By 2030, that number will have risen to 150 million, the International Energy Agency believes. And those looking to play a dominant role in that market will have to offer fast-charging batteries that can store more energy, have a longer lifespan, are safer and cost less.
A price of $100 per kilowatt-hour (currently, it lies at around $160 per kilowatt-hour) is seen as the barrier at which electric cars will be cheaper than internal combustion vehicles. At that point, it will just be a matter of time before the world’s 1.2 billion vehicles are replaced by their electric counterparts.
Battery expert Maximilian Fichtner of the Helmholtz Institute Ulm is full of praise for the technology’s efficiency. “With hydrogen propulsion, only about 15 to 20 percent of the energy produced really makes it to the wheels. With batteries, it is 70 to 75 percent. Without high-performance batteries, the energy and mobility revolution cannot succeed.”
Most of the batteries in today’s electric vehicles are of the lithium-ion variety. This type of battery was introduced by Sony in 1991. When such a battery discharges, lithium ions move from the battery’s negative pole (the anode) and its positive pole (cathode) through liquid electrolyte and a separator membrane. The electrons shed at the anode also make their way to the cathode, but not through the battery, instead traveling through the attached electrical circuit. The process is reversed during charging.
The Most Energy in the Smallest Possible Space
Lithium-ion batteries have become standard in the automobile industry – as they have for many other products, ranging from mobile telephones to electric lawn mowers – because they are light and have a large storage capacity. The chemical configuration of anode, cathode and electrolyte determine how well the battery works. Chemists and engineers have experimented with manganese, cobalt, magnesium, graphite and sulfur; they have tried out iron, nickel and silicon, with liquid and solid electrolyte. The trick is to combine the materials such that as much energy as possible can be stored in the smallest space possible.
“We are looking for the all-rounder,” says Martin Winter, head of the battery research center MEET at the University of Münster and of the Helmholtz Institute Münster. The chemist and his 250 colleagues research electrolyte compounds for conductivity and temperature stability. Hundreds of handmade batteries undergo testing in the institute’s climate chambers.
The researchers produce anodes and cathodes from a number of different mixtures of materials in the form of 80-micrometer-thin electrode foil. In a dry room – necessary because the metallic lithium the scientists work with reacts aggressively to water – the electrodes are assembled into “pouch cells,” flat batteries that look like the aluminum pouches for instant mashed potatoes. The researchers then determine the electrochemical properties of the test batteries. Each variety has different parameters for energy density, lifetime, safety, cost and environmental sustainability.
Traditionally, the cathodes of lithium batteries have been made with lithium cobalt oxide. But cobalt is expensive, and much of it comes from the Democratic Republic of Congo, where miners work under inhumane conditions. Furthermore, child labor is widespread in the country and spoil heaps from the mines contaminate the environment.
In response, scientists and industrial leaders have long been trying to reduce the amount of cobalt used in their batteries. For example, the Chinese company CATL, which partners with Tesla, started mass-production last year of nickel-manganese-cobalt and nickel-cobalt-aluminum cells. They contain only 2 to 3 percent cobalt – a 90 percent reduction from earlier batteries.
Tesla wants to go even further, with Musk having announced his intention to produce cobalt-free batteries, hoping to completely replace the controversial element with nickel. In other batteries, Tesla wants to use cathodes made of lithium iron phosphate. A pioneer in this technology is the Chinese company BYD, which has been selling a vehicle equipped with such batteries since July. The luxury electric vehicle, called the BYD Han, has a range of 600 kilometers on a single charge.
BYD presented an additional advantage of this technology in March, when the battery, which the company calls Blade, passed the “nail penetration test.” The test involves driving a three- to eight-millimeter thick nail through the battery, thus triggering a short circuit. Standard lithium-ion batteries frequently heat up to over 500 degrees Celsius and burst into flames when pierced in this manner, which presents serious dangers in the event of a car accident. The iron phosphate battery from BYD experienced no such trouble, with the temperature of the Blade only rising by a paltry 60 degrees Celsius, according to the company.
“Lithium iron phosphate batteries are definitely safer,” says Winter, the battery scientist at the University of Münster. They also have a longer lifespan, he says. Yet the same volume of lithium iron phosphate, he says, can store less energy than other cathodes.
Energy density is considered one of the most important characteristics for batteries. The best commercial batteries at the moment have a density of around 260 watt-hours per kilogram. Some startups, though, have pledged to develop a density of up to 1,000 watt-hours per kilogram.
For such high performance, the battery’s anode also must be built differently. In this respect, hopes are high for the lithium-metal anode. In the technology most frequently used for anodes thus far, lithium atoms are embedded in graphite. The more lithium is packed in, the greater the battery’s energy density. With the lithium-metal anode, however, the repository itself is made of lithium, which can boost the battery’s energy density by up to 65 percent. Plus, it makes the batteries lighter.
The Tesla Way
But it’s not quite that easy: Lithium is extremely reactive. Needle-like growths can develop on the surface of the anode – so-called dendrites. If they become too large, short circuits can be the result, with the battery even exploding in the worst-case scenario.
Researchers hope that protective coatings and special electrolytes can prevent the development of dendrites. Others are looking into using conductive plastics or ceramic materials instead of the liquid electrolyte most commonly used thus far. Called solid-state batteries, they, too, are said to have a higher energy density and can be charged more quickly. Toyota has announced its intention to introduce a solid-state battery by 2025 and the company has reported on prototypes that can be charged in just 15 minutes.
Tesla, for its part, has settled on a different material for its anodes, one for which many also have high hopes: silicon.
The element has thus far been considered a difficult material for anodes because its volume quadruples as soon as lithium is embedded in it. But Tesla claims to have solved that problem, with the company saying the material can be stabilized with an elastic polymer coating. It is cheaper, available in almost unlimited quantities and it can store nine times more lithium than graphite.
“There would no longer be any reason to buy an internal combustion vehicle – not even the price.”
More than anything, though, Tesla is focusing on improved production strategies for its batteries. Musk’s factory designs are spectacular. If the alleged achievements of the pilot facility in Fremont can be repeated at a much larger scale, then the investment costs for the company’s battery factories – called tera factories – will shrink by almost 70 percent. Musk also intends to build a battery factory at the Grünheide site just outside of Berlin.
Tesla is planning a “dry” production procedure for the electrodes, which would obviate the need for solvent and eliminate several steps in the production process. Furthermore, engineers have been able to drastically shorten the wiring within the batteries, a technology that Tesla has adapted from Maxwell, a company it bought last year. The result is that the electrons don’t have to travel as far, and less heat is created. That means the battery cells can be larger and packed more densely. Not only that, but such a system can be charged up to six times faster, says Tesla.
The bottom line is that batteries produced in this manner should have a range that is 54 percent greater and a cost that is 56 percent lower than today’s batteries. “That would put us at a cost of between $70 and $80 per kilowatt-hour,” says Maximilian Fichtner from the Helmholtz Institute Ulm. “There would no longer be any reason to buy an internal combustion vehicle – not even the price.”
Tesla also wants to forge ahead on recycling. The battery system of a Tesla Model S can weigh more than half a ton and they are packed full of valuable metals. Recycling that material is decisive to keep the environmental and climate impacts of the future flood of batteries as low as possible. “When it comes to batteries, we really do have good chances of creating a closed-loop recycling system,” says Fichtner. More than 90 percent of the materials used in batteries can be recycled. In addition to cobalt, it could be particularly profitable to recover the nickel and copper.
To this point, though, a mere 5 percent of the lithium used in batteries is recycled. And the substances most often used in batteries are extremely unevenly distributed around the world. The overwhelming majority of lithium comes from Australia and Chile, some 72 percent of the world’s graphite is produced in China and more than half of all cobalt comes from DR Congo.
Germany Lags Far Behind
In response, researchers have long since begun conceiving batteries that require no lithium at all. They are hoping to find substances that are environmentally friendly, cheaply available and based on elements that are more readily available.
This is Fichtner’s area of expertise. Post Lithium Storage, or POLiS, is the name of a research association involving scientists based in the German cities of Ulm and Karlsruhe. As part of that association, Fichtner is looking into replacing lithium with natrium, magnesium or potassium. “Especially for battery types that use large quantities of material, it makes more sense to use sustainable substances,” Fichtner says. As an element of sea salt, natrium is available in almost unlimited quantities, he says. Magnesium, meanwhile, can be found in the mineral dolomite, out of which, for example, “almost the entire Swabian Jura” is made, he says, referring to the low range of mountains in southwestern Germany.
“It does stand out that when it comes to mobility, we in Germany have done all we can to prolong the lifespans of old technologies.”
Such alternative batteries, though, still aren’t as productive as their lithium-ion forebears. Nevertheless, the first natrium batteries are scheduled to hit the market this year. “They will likely be used in power tools or electric bicycles initially,” Fichtner says. The next step, he hopes, is large batteries for the storage of wind- and solar-generated energy. The batteries in the basements of apartment blocks that have roof-top solar panels could also soon operate without the need for lithium, he believes.
For cars, though, lithium technology will remain standard for the foreseeable future. “The energy density of current lithium technology is three times as high as for today’s natrium batteries,” says Winter. And by 2025, a 50 percent increase in energy density is possible, he believes.
He also argues that Germany’s lack of battery production facilities is the height of negligence. Carmakers in the country have thus far depended on the technological pioneers in the Far East, with experts saying that Asian companies have a five- to seven-year head start. “It does stand out that when it comes to mobility, we in Germany have done all we can to prolong the lifespans of old technologies,” Winter says.
In order to catch up, he says, leading German researchers must cooperate more closely with industry. In that vein, the German federal government and the state of North Rhine-Westphalia have ponied up 700 million euros for the erection of a research factory. Research results are to be translated there into serial production. Winter believes the factory represents a great opportunity: “If Germany only corners 5 to 10 percent of the expected giga-market, it would be a gigantic success.”
Whether it will be possible to compete with Tesla on the long term, though, is questionable. The start-up costs for battery factories are vast and many German carmakers are experiencing corona-related difficulties, making such investments even more difficult to afford. Musk, though, has achieved a stock-market value for his company that is greater than all German carmakers together.
And he boasts that he has laid the groundwork for future success. Tesla, for example, has secured access to lithium deposits in Nevada, just hours away from the Tesla Gigafactory. Nevada, Tesla announced in Fremont, is home to enough lithium to electrify the country’s entire fleet of automobiles.
The Tesla CEO has nothing but scorn for internal combustion vehicles. On Tuesday, he said that he doesn’t believe the industry will be around for much longer. The comment earned him a chorus of honking.