Electric cars

Sulfur battery technology could allow electric cars to go three times farther by 2024

Sulfur battery technology could allow electric cars to go three times farther by 2024

The limited range is one of the most frequent criticisms of electric vehicles. Although a 300-mile rating is increasingly common for today’s electric cars, some fossil-fuel models can go twice as far on one tank. But what if your BEV could travel 900 miles on a single charge? German battery startup Theion is a promising technology that could offer this possibility as early as 2024.

the the key to theion’s technology is sulfur, and in fact the company name is derived from the Greek for this yellow mineral. According to CEO Dr Ulrich Ehmes, it has the properties required to revolutionize battery chemistry, with indirect benefits in all key areas for electric vehicles. Co-founder and CTO Marek Slavik had been working on the technology for almost a decade, and Ehmes recently arrived to make it a production reality.

As many EV haters on social media will tell you, EV batteries are full of rare earth minerals, making them expensive and ethically problematic to manufacture, especially when sourcing them. cobalt from the Congo. Theion’s strategy is to base its battery technology on minerals that are far more abundant than those used in current Lithium-Ion cells, but which have similar energy density potential.

Sulfur is the tenth most abundant element on Earth, and local sources are usually available at any chosen location in the world. “Existing battery technology uses nickel, manganese and cobalt for the cathode,” says Ehmes. “It’s called NMC 811 because it contains 80% nickel, 10% cobalt, 10% manganese. In our case, we replace this NMC 811 with sulfur. So we have no nickel, no manganese, no cobalt, and we’re replacing the current collective plies of copper and aluminum with graphene, so we also have no aluminum and no copper in our cells. The only things we have in our cells are metallic lithium foil, sulfur and carbon. For this technology to work, the sulfur must be melted to form crystals, but it is only 112C (235F).

So what are the benefits of Theion’s radical change in battery chemistry? Sure, you can get an electric vehicle 900 miles with today’s battery technology. The problem would be the weight of this battery and the space it requires. Current electric vehicles consume between 3 and 5 miles per kWh, although the energy consumption can be much higher if you drive “spirited” or in extreme temperatures. Let’s say 4 miles per kWh to be fair. Using this figure, you would need 225kWh to drive 900 miles. Current Tesla Model 3 “2170” batteries have a density of 260Wh/kg, although the latest technology can reach 350Wh/kg. Assuming the latter, a 225kWh battery would weigh 643kg, but with Tesla 2170 cells it would weigh 865kg. With a Tesla Model 3 Long Range weighing around 1,850 kg, you can see why no electric vehicle today offers a range of 900 miles.

Battery weight is derived from the “gravimetric density” of the cells, but the other consideration is the “volumetric density” – the space occupied by the batteries. Tesla Model 3 2170 batteries are said to have a volumetric density of 416 kWh/liter. Although the weight is important, you should also place your batteries in a reasonable space, so that there is enough left for passengers and cargo. Most current designs place the batteries in a ‘skateboard’ design under the floor to maximize this space, but you still see many EVs sitting higher than internal combustion equivalents to provide the necessary floor thickness .

When Tesla switched to LFP batteries in the standard Model 3 in Europe it lost both gravimetric and volumetric density due to shortcomings of this technology compared to lithium-ion, but the Model 3 battery case was designed to accommodate the larger batteries of the long range and performance, so this base model might just take up more space in the battery case. Tesla appears to have increased the battery size to deliver the latest WLTP range of 305 miles while sacrificing some acceleration due to the added weight of the LFP.

Ehmes says Theion’s technology will dramatically increase gravimetric and volumetric density, so its batteries take up less weight and space for the same capacity, or you can have a lot more capacity for the same weight.

Theion’s current Gen 1 technology is already at 500 Wh/kg and 800 Wh/litre – well above Tesla’s 2170 cells. But Gen 2 technology promises to take that to 700 Wh/kg and 1,000 Wh/litre in 2023, followed by Gen 3 in 2024 which will deliver 1 kWh/kg and 1,200 Wh/l. Going back to our car with a range of 900 miles, its battery would weigh only 225 kg. That would be around 60kg lighter than the current battery in the Tesla Model 3 Long Range, which has a WLTP rating of 374 miles, and take up around a third of the space. Theion’s Gen 4 battery, due in 2025, will have a slightly lower gravity density of 900 Wh/kg, but a higher volumetric density of 1,500 Wh/litre – so it would take up just over a quarter of the space of a Tesla Model 3 Long Range the battery. Theion also promises 2,000 charge-discharge cycles for its Gen 3 and 4 technologies, which is higher than the 1,000-1,500 cycles of current Lithium-Ion cells.

Another important aspect is of course the price, and Theion promises incredible discounts here too. “Our price target is €30 per kilowatt hour compared to €90 per kilowatt hour today,” says Ehmes. Indeed, the materials used by Theion are cheaper, as is the energy consumption. “The production energy is 90% lower.” With batteries accounting for about a third of current electric vehicle costs, this reduction would easily push the total price of cars well below that of internal combustion vehicles. This current 225kWh for 900 miles pack would potentially be the same kind of price as a 75kWh for 300 miles pack today.

Unfortunately, Theion will not initially supply its technologies to the electric vehicle industry. “We are currently talking with the space industry,” says Ehmes. “We will then hand over the surplus R&D to the air taxi. Then mobile devices like handhelds, laptops, cell phones, and wearable devices. But electric vehicles are definitely on Theion’s roadmap, and production has been designed to accommodate the quantities electric cars require.

Assuming this technology delivers as promised, it could remove one of the last barriers to EV adoption. A city car with a range of 300 miles would have a battery that weighs just 75kg and takes up only 50 liters of space. In comparison, a Tesla Model 3 Long Range battery delivering this autonomy takes 180 liters. But if you outfitted a car like the Tesla with Theion’s technology, it could easily go 900 miles or even more on a single charge with the same size and weight battery it has now.

Of course, a 225kWh battery like this would take about 30 hours to charge on a 7.4kW home charger, and probably over an hour to get to 80% on even the most popular public DC fast chargers. fast. But if you can go 900 miles on a charge, you may never need to use a public charger.

It should be remembered that, although electric vehicles and internal combustion cars were invented around the same time (at the end of the 19and century), electric vehicles took much less time to develop. The electric vehicle as we know it today has only really been around for a decade, while internal combustion has been steadily improving for over 100 years. The EV is already smoother to drive, faster and cheaper to run than internal combustion. It will clearly not be many more years before technology such as Theion’s will mean that electric vehicles will also go further between refueling stops.