The requirement for Arcola Energy’s powertrain platform, and for FCEV vehicles in general, is high-power batteries, minimising weight and lifetime cost.
In a fuel cell electric powertrain, the battery provides power delivery and regenerative braking acceptance, so power density for both change and discharge is critical. The battery is carefully managed within the system, operating between 40% to 80% SoC in micro-cycling mode so deep discharge cycles are rare.
Battery lifetime in this high-power, heavy-duty application is critical. Buses do 5,000 hours per year and operate for at least 15 years, so 75,000 hours is expected. Safety in this heavy-duty environment is essential of course, and good thermal stability characteristics are valuable. Compliance with appropriate standards (Reg 10 and Reg 100.02) is essential.
The current benchmarks at pack level are:
- Gravimetric power density: 500 kW/kg for peak power (10s) charge and discharge
- Cost: $150/kW (peak)
- Lifetime: 75,000+ hours in micro-cycling mode for road vehicles
Other factors are also relevant, but of lower priority with the benchmarks for current technology:
- Volumetric power density: 750 kW/l
- Gravimetric energy density: 60kWh/kg
The survey asks to what extent these targets can be met now and the R&D requirements to achieve and exceed these in the future.