Both are true.coleafrado wrote: ↑Sat May 30, 2020 11:57 amNot to mention that Al-air discharge efficiency (when recycling is accounted for) is about the same as internal combustion.LeftieBiker wrote: ↑Fri May 29, 2020 1:54 pmI remember an aluminum-air prototype car back in the Nineties. The discharge output was so low that they needed to add a smaller Ni-Cad pack just so the car could accelerate on the highway. They had more luck with a bus, again, IIRC, with a second pack for acceleration. The aluminum modules had to be replaced regularly as they were exhausted.
The first point is why a hybrid battery is the only realistic way to handle this. Power output of a 100kG Al-air battery would be on the order of 20kW to 40kW;. That's enough for a steady speed, but not enough for significant hill climbing or for zippy acceleration. It also responds to the airflow through the battery, so output is delayed while the air pump speeds up airflow. Regeneration energy can't be captured by the Al-air as well.
The second point is also true. With a hybrid battery, as most trips are short, so most of the total energy used is stored in the Li-ion battery. About 75% of miles driven are on trips under 100 miles. Some of the longer trip's miles would also be on the more efficient Li-ion battery. The Al-air also has the potential to be a way to shift energy seasonally. Renewable energy is more abundant in some seasons and less in others. Produce Aluminum while the Sun shines, and use it when needed.
I'm not sure if this is ever going to be mainstream rather than niche. Decades away at best.