Sulfur battery technology might double the range of electric cars

Compared to the core ingredients of conventional NMC li-ion batteries, sulfur is cheap.

The limited range of EVs is one of the most often leveled critiques. While a 300-mile range is becoming more common for modern electric vehicles, certain fossil-fuel vehicles can travel twice that far on a single tank. However, what if your BEV was capable of traveling 900 kilometers on a single charge? Theion, a German battery company, says it has technology that could make this possible in 2024.

Sulfur is critical to Theion's technology, and the company's name is taken from the Greek word for this yellow mineral. According to CEO Dr. Ulrich Ehmes, it possesses the qualities necessary to usher in a revolution in battery chemistry, resulting in advantages across the board for electric vehicles. Marek Slavik has been developing the technology for the better part of a decade. Ehmes has lately come to bring it to production.

Many EV detractors on social media can attest that EV batteries include rare earth materials, making them pricey and morally problematic to produce, mainly when cobalt is sourced from the Congo. Theion's approach is to build its battery technology on minerals that are significantly more plentiful than those utilized in today's Lithium-Ion cells yet have a comparable energy density potential.

Sulfur is the tenth most plentiful element on Earth, and it is often available locally in any given place. "Present battery technology utilizes nickel, manganese, and cobalt as the cathode material," Ehmes explains. "It is named NMC 811 because it contains 80% nickel, 10% cobalt, and 10% manganese. In this example, we substitute sulfur for the NMC 811. Thus, we eliminate nickel, manganese, and cobalt from our cells. We replace the present collective folds of copper and aluminum with graphene, eliminating aluminum and copper from our cells. Our cells contain merely lithium metal foil, sulfur, and carbon." The sulfur must be melted to create crystals to make this technique function. This takes place at only 112 degrees Celsius (235F).

What are the benefits of Theion's paradigm-shifting battery chemistry? In fact, with current battery technology, an EV could travel 900 miles. The issue would be the battery's weight and space required. Current EVs get between 3 to 5 miles per kWh, but this figure may be significantly higher if driven "spiritedly" or in harsh conditions. Let us assume 4 miles per kWh; 225kwh would be required to travel 900 miles. Tesla Model 3 "2170" batteries now have a density of 260Wh/kg, although advanced technology can achieve 350Wh/kg. Assuming a density of 350Wh/kg, a 225kWh battery would weigh 643kg, but 865kg if it included Tesla 2170 cells. With a Tesla Model 3 Long Range weighing 1,850 kilograms, it is easy to see why no other EV currently available has a 900-mile range.

The weight of the battery is determined by the "gravimetric density" of the cells, but another factor to consider is the "volumetric density" - how much space the batteries occupy. According to Tesla, the Model 3 2170 batteries have a volumetric density of 416 kWh/liter. While weight is critical, you also need to pack your batteries into a fair amount of space so that passengers and luggage have enough room. While most current designs place the batteries beneath the floor in a "skateboard" configuration to utilize this space, many EVs nevertheless sit higher than their internal combustion counterparts to offer the requisite floor thickness.

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When Tesla switched to LFP batteries in the standard Tesla Model 3 in Europe, it sacrificed both gravimetric and volumetric density due to the technology's shortcomings compared to Lithium-Ion. Still, the Model 3's battery box was designed to accommodate the larger batteries in the Tesla Long Range and Tesla Performance, so this base model could take up more battery box space. As a result, Tesla looks to have upped the battery capacity to achieve the new WLTP range of 305 miles while losing some acceleration owing to the added weight of LFP.

 Ehmes says that Theion's technology will significantly improve both the weight and volume density of its batteries, allowing them to either be lighter or take up less space while still having the same amount of power for the same weight.

 Theion's current Gen 1 technology already exceeds Tesla's 2170 cells by 500Wh/kg and 800Wh/liter. However, Gen 2 technology is expected to increase this to 700Wh/kg and 1,000Wh/liter in 2023, followed by Gen 3 in 2024 at 1kWh/kg and 1,200Wh/l. Returning to our 900-mile-range automobile, its battery would weigh just 225kg. This would weigh around 60 kg less than the existing battery in the Tesla Model 3 Long Range, which has a 374-mile WLTP range and would take up roughly a third of the available space. Theion's Gen 4 battery, scheduled for release in 2025, will have a slightly lower gravimetric density of 900Wh/kg but a greater volumetric density of 1,500Wh/liter — taking up just over a fourth of the area required by a Tesla Model 3 Long Range battery. Theion also promises 2,000 charge-discharge cycles for its Gen 3 and 4 technologies, which is much more than the existing Lithium-Ion cell's 1,000-1,500 cycles.

 Another critical factor is pricing, and Theion is also offering incredible discounts on this. "Our goal price is €30 per kilowatt-hour, down from €90 per kilowatt-hour now," Ehmes explains. This is because Theion's materials are more affordable than its energy usage. "Production energy consumption is reduced by 90%." With batteries accounting for around a third of current EV costs, this decrease would quickly bring overall car prices down to levels comparable to internal combustion cars. That present 225kWh battery with a range of 900 miles may cost the same as a 75kWh pack with a range of 300 miles.

Regrettably, Theion will not initially supply its solutions to the electric vehicle market. "We are now discussing the space business," Ehmes explains. "We will then turn over the excess RD to the air taxi." Following that, mobile devices such as handhelds, laptops, smartphones, and wearables." However, electric cars are undoubtedly on Theion's list of things to work on, and production has been stepped up to meet the demand for electric cars.

 If this technology performs as advertised, it has the potential to remove one of the remaining hurdles to EV adoption. For example, a 300-mile range city vehicle would have a battery weighing just 75kg and taking up less than 50 liters of space. By contrast, a Tesla Model 3 Long Range battery providing a similar range requires 180 liters. However, if a car like Tesla were equipped with Theion's technology, it could quickly go 900 miles or more on a single charge with a battery the same size and weight as the one that comes with the car.

Recharging a 225kWh battery takes roughly 30 hours on a 7.4kW home charger and possibly more than an hour on even the quickest public DC rapid chargers. However, if you can travel 900 miles on a single charge, you may never use a public charger.

It is worth noting that, while both electric vehicles and internal combustion engines were conceived about the same time, EVs have advanced far more rapidly. The EV as we know it now has only been for about a decade, but internal combustion has been developing slowly for over a century. The electric vehicle is already more comfortable to drive, faster, and less expensive to operate than internal combustion engines. It will not be long until technology like Theion enables EVs to go longer between refueling stops. @via EV stories and Cleantechnica.

Floris Muna

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