Farasis Energy claims breakthrough in million-mile battery

Chinese lithium-ion battery cell maker Farasis Energy, which supplies Geely, Mercedes-Benz, and Turkish Togg, among others, claims to have successfully achieved durable NMC cells for a million-mile (1.6 million km) battery in lab testing. Battery packs using these cells can last a million miles over 15 years while retaining over 70% of their capacity, even with fast charging.

The latter required cycling its NMC cells P75 and P73, developed since 2018, over 5,000 times, a process that takes 24 to 36 months of accelerated testing at varying temperatures of 25°C to 35℃. The cell maker explains that cell capacity degradation depends on factors such as cell temperature, depth of discharge, charge rate, discharge rate, pressure, and storage temperature.

Coated with semi-solid gel

Farasis Energy says its testing incorporated strenuous usage scenarios going further than industry-standard test conditions (25℃ and C/3 rate), including fast charging. That means charging a battery from 10% to 80% in around 20 minutes for P75, and around 30 minutes for P73 and a high depth of discharge of 90% and above.

Advanced materials and charging strategies achieve a long cycle life. “The separators are coated with semi-solid gel to reduce the amount of electrolyte while ensuring excellent ion conductivity and chemical stability.”

“The cathode and anode materials have excellent stability, and the electrolyte and electrode interface are optimized for improved performance. The charging strategy is optimized to reduce lithium plating and heat generation, effectively suppressing the side reactions that cause capacity loss,” the press release states.

Heavy trucks and buses

Mercedes uses Farasis cells in its high-end vehicles, but even those won’t need a ‘million-mile battery’. On average, Farasis says, consumer vehicles reach no more than 200,000 miles (320,000 km), but commercial vehicles usually do.

“Traditionally served by diesel engines, commercial vehicles can benefit from the lower operating costs of electric powertrains, which are half that of diesel engines when considering maintenance and fuel/electricity costs. Long-lasting battery packs in commercial vehicles provide significant financial and environmental benefits to operators and the public,” the cell maker claims.

Farasis Energy, one of the then-biggest battery cell makers globally, was founded in 2002 and has its headquarters in Ganzhou, Jiangxi, China. It has R&D centers in the US (Silicon Valley), Germany (Stuttgart), Turkey (Gemlik), and China. The production of battery cells is concentrated in China.