Farasis Energy Achieves Breakthrough with Million-Mile Battery Cells: Enhanced Longevity, High Energy Density, and Advanced Safety Features

Farasis Energy Achieves Breakthrough with Million-Mile Battery Cells: Enhanced Longevity, High Energy Density, and Advanced Safety Features
Image credit: Farasis Energy 

Farasis Energy has announced a major milestone in battery technology with the successful testing of its innovative battery cells, marking significant progress in the development of a million-mile battery. Achieving this milestone requires cells to endure over 5000 cycles of rigorous testing, a process spanning 24 to 36 months.

Since 2018, Farasis Energy has tested its NCM chemistry cells, the P75 and P73, to understand their cyclic and calendar aging characteristics. These tests have shown that battery packs using these cells can last up to a million miles over 15 years, retaining over 70% of their capacity. The capacity degradation of battery cells depends on several factors such as temperature, depth of discharge, charge and discharge rates, pressure, and storage conditions. While many cells perform well under standard test conditions (25℃ and C/3 rate), real-life conditions are often more demanding. 

Farasis Energy test results for its NCM chemistry cells
Image credit: Farasis Energy 

Farasis Energy has subjected its cells to strenuous scenarios, including fast charging (10% to 80% in approximately 20 minutes for P75 and 30 minutes for P73) and high depth of discharge of 90% and above. The tests also involved varying temperatures (25 to 35℃) to reflect conditions in major automotive markets like the coastal United States, Western Europe, and China. Additionally, the test fixtures simulated real-life pressure conditions encountered in battery packs/modules.

Advanced materials and charging strategies contribute to the long cycle life of these cells. The separators are coated with semi-solid gel to minimize electrolyte use while maintaining ion conductivity and chemical stability. The cathode and anode materials are stable, and the electrolyte-electrode interface is optimized for better performance. An optimized charging strategy reduces lithium plating and heat generation, curbing side reactions that lead to capacity loss.

Internal structure of the new Farasis Energy battery cell
Image credit: Farasis Energy 

These battery packs offer not only long life but also high energy density, quick charging (20 to 30 minutes), and thermal propagation mitigation. They are mass-produced for high-end vehicles like Voyah (the premium arm of Dongfeng) and Mercedes-Benz, as well as commercial vehicles. The cells achieve up to 285 Wh/kg energy density, extending the range for heavy-duty electric trucks by an additional 300km compared to LFP-based battery packs.

Farasis has also developed unique packaging technologies to ensure safe operation, including a directional exhaust system, multi-sided thermal barrier protection for each cell, thermoelectric separation, and phase change materials to absorb heat during thermal events. These features prevent the spread of thermal propagation, significantly enhancing safety.

The different packages of the Farasis Energy battery cell
Image credit: Farasis Energy 

Commercial vehicles, which often exceed 200,000 miles, benefit from the lower operating costs of electric powertrains compared to diesel engines. The long-lasting battery packs offer substantial financial and environmental advantages. Additionally, leaders in the electric vehicle takeoff and landing (eVToL) market have independently validated these cells, noting their durability over 10,000 flight cycles and preferring Farasis's pouch cells over cylindrical and prismatic options.