Lithium Sulfur, Lithium Carbon — Batteries Have Come A Long Way, Baby

September 23, 20213 years ago Steve Hanley 0 Comments

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Ready for some battery tech news? Both Lyten and MAHLE have announced new battery technology breakthroughs and neither of them is some pie-in-the-sky experiment from the laboratory that is 10 years away from production. Both promise lower costs, faster charging, and reduced flammability. Let’s take a closer look.

Lyten Lithium-Sulfur Battery

California-based Lyten has been working on lithium-sulfur battery cells for the Department of Defense for several years. In a press release, it says it is ready to move from defense applications to powering electric vehicles. What’s so special about Lyten technology? Energy densities of up to 900 Wh per kg — roughly three times greater than conventional lithium-ion batteries.

The secret is a special 3-dimensional graphene that took years to refine. This unique material can be engineered and tuned at the molecular level to specific battery application requirements, the company says. It makes it possible to unlock the performance potential of sulfur by arresting the “poly-sulfide shuttle,” a compromising factor that shortens battery life and has prevented the use of lithium-sulfur batteries in electric vehicles until now. During Department of Defense testing, a LytCell™ prototype design has survived more than 1,400 charge/discharge cycles.

“We have begun a generational transformation from internal combustion engines to BEVs. We’re confident that Lyten’s breakthrough battery platform will accelerate the mass consumer adoption of electric vehicle ownership due to the performance, range, and safety improvements of our LytCell EV™ batteries,” says Dan Cook, CEO and co-founder of Lyten. “By also delivering the most environmentally responsible battery with a USMCA-compliant supply chain, we believe Lyten will enable automakers to more confidently execute their announced electrification roadmaps.”

The company says its lithium-sulfur batteries are safer than conventional lithium-ion batteries because they do not contain oxygen from metallic oxides. That oxygen is what promotes the thermal runaway events that have plagued many EVs, particularly the Chevy Bolt.

In addition, the company says its batteries will make electric cars less expensive than conventional cars with internal combustion engines. They can operate at temperatures as low as -30 degrees Celsius or as high as 60 degrees Celsius. Flexible and scalable pack sizing will make it possible for Lyten batteries to meet the needs of a wide range of automotive platforms.

The batteries can be produced in cylindrical, pouch, and prismatic formats at production facilities near auto factories. The company says its batteries have the lowest carbon footprint of any EV battery, can charge in under 20 minutes, and contain no conflict materials such as cobalt. It expects full production and market availability for 2025 and 2026 model-year vehicles.

MAHLE Lithium-Carbon Battery

MAHLE Powertrain test facility. Credit: MAHLE

We tend to focus on automobiles here at Casa CleanTechnica, but in many parts of the world, scooters and mopeds are the vehicles of choice, especially in crowded urban environments. Germany’s MAHLE is a Tier One supplier to the automotive industry. It has partnered with Allotrope Energy to create a battery for small vehicles that combines the features of a traditional lithium-ion battery with those of a supercapacitor.

Allotrope’s lithium-carbon battery is fully recyclable, uses no rare earth metals, is not susceptible to thermal runaway events, and can be recharged in as little at 90 seconds. “Range anxiety is often quoted as the main barrier to electric vehicle adoption, but if the battery could be recharged in the same time it takes to refuel a conventional IC engine vehicle, much of that worry goes away,” says Mike Bassett, MAHLE Powertrain’s head of research.

“With the rise of the on-demand economy, there’s been a rapid increase in the use of petrol powered mopeds for urban deliveries such as take-away meals and this has contributed to air quality issues in our cities. Decarbonizing these deliveries has so far proved difficult without maintaining a stock of expensive interchangeable batteries or switching to a larger, heavier electric vehicle with increased energy consumption,” Bassett says. (Interchangeable batteries that can be swapped easily are coming from Piaggio, KTM, Honda, and Yamaha.)

Allotrope Energy’s lithium-carbon technology combines the benefits of supercapacitors and traditional lithium-ion batteries to deliver a cell that can be recharged quickly and yet retains good energy density. The technology features a high-rate battery anode and a high capacity electric double layer capacitor cathode separated by an organic electrolyte.

The result is a battery cell that suffers none of the thermal degradation effects experienced by traditional lithium batteries. Its stability, even at high temperatures, permits high current delivery and fast recharging, all without the need for complex external cooling or elaborate battery management systems.

The best part is: the batteries are inexpensive and the capacitor style cathode is good for more than 100,000 cycles. The elimination of rare earth metals and the design’s complete recyclability make it better for the environment both during production and long after it.

As part of the project, MAHLE Powertrain investigated using the lithium-carbon batteries to power electric mopeds for fast food delivery within a 25 km target range. The lithium-carbon battery can be recharged at 20kW in just 90 seconds, meaning a full charge could be obtained in the time takes the next order to be delivered.

“With ultra-fast charging, the size of the battery can be optimized to suit the scenarios the vehicle will be used in, and that leads not only to weight savings but also cost reductions that further lower the barriers to decarbonization,” Bassett claims. “The real challenge came in designing the electrical architecture capable of absorbing such high rates of charge.”

That’s all well and good, but chargers that can deliver 20 kW of power are not common, “So we created our own bespoke design,” he adds. The solution his team came up with uses its own built-in capacitor-based energy storage module to deliver ultra-fast charging by augmenting the power from a typical 7 kW single phase connection. That reduces costs and complexity while eliminating the need for expensive power grid connection upgrades.

The Takeaway

Triple the power density; one third the charging time. Some amazing things are happening as the EV revolution picks up speed. Nobody today remembers cars that had to be started using a hand crank. Before long, nobody will remember when cars had internal combustion engines. That day is getting closer all the time.