A battery powered plane is possible in the same vein that a fusion powered plane is possible - it's not at all possible with current technology and anything in the foreseeable future.
There are battery electric "regional commuter" two-seater planes on sale today. There's a 9-seater prototype that has completed short hop test flights [1]. Right now almost all of that is short-hop, but the excitement in that growing industry is that may disrupt the economics of even long range jet flights before long. (Not just "foreseeable future" but "sooner than you think".) (The efficiencies of battery electric for planes is apparently really interesting: that battery motor full torque access apparently a game changer for some types of flight dynamics. Or so I've heard.)
> The aircraft flew at more than 100 mph to an altitude of around 2,500 feet, made a few turns and then landed after 28 minutes
This isn't going to disrupt any kind of airline traffic. Battery energy density needs to improve by at least an order of magnitude - probably two - before it has any significant aerospace application outside of drones.
Already practical for some applications but needing work to more, even possibly a lot of work, is still a vast difference from "never in the foreseeable future".
Regional planes that only travel 30 minutes to an hour and do so cheaper and more efficiently than gas/diesel equivalent planes can still massively disrupt the big passenger airlines. It used to be that the airlines had a wider mixture of 30 minute/1 hour flights on smaller commuter planes to smaller "regional" airports before the economies of scale of jet engines pushed everything bigger (fewer flights below 1 hour in distance; more "hub-and-spokes" centralization; etc). A return of cheap, efficient short 9 or so passenger commuter flights could massively disrupt today's passenger airlines and their logistics, not just tomorrow's.
If electric efficiencies also manage to scale to the bigger flights, who knows what will happen, but it is something to watch that there's already practical disruption implications even before scaling it up that big.
No, it's not practical for any application - at least none besides drones. A 737 has 150-200 seats, this would entail 17 separate 9-seater electric planes - each of which needs its own pilot - to substitute one regional jet. Ticket price would have to be extremely high just to fulfill the labor cost of operating the aircraft, because of this high staff to passenger ratio. There's also no mention of how long it took to recharge these batteries after the 30 minute flight - a plane that needs to sit for several hours to recharge between each 30 minute flight is not going to yield a return on investment.
Most regional airline flights are 50-100 seats. "Tiny" aircraft by airline standards are things like turboprop passenger craft [1]. A single digit number of seats is much more niche than regional flights. It's limited to island hopping and bush flying in remote areas - a much more limited market than regional flights. 2 hours of labor split 9 ways instead of 90 ways increases your labor cost by an order of magnitude. And again, it's unclear if that electric plane could even lift 9 passengers - it's just a plane with 9 seats, there was no mention as to whether or not the mass of passengers in those seats were simulated with a load.
Scaling up would make it more efficient, but batteries' limitations prevent larger planes. Hence, why more energy dense fuels are required.
The earlier point remains that if that economics flips and rather than doing 3 hour-ish flights of 50-100 people between modest "hubs" you had more opportunities to do shorter point-to-point (1 hour/30 minutes/less) you light up a lot of possible flight legs that current passenger flight has ignored for decades.
(In some cases you light them back up because earlier periods of passenger flight did have less hub-and-spoke/deep centralization and a lot more airports and airfields overall than are in operation today.)
I'm not sure it is going to happen, but I wouldn't underestimate the potential there either just because it doesn't look like the status quo. That's kind of the definition of "disruption".
> you had more opportunities to do shorter point-to-point (1 hour/30 minutes/less) you light up a lot of possible flight legs that current passenger flight has ignored for decades
And my point is that this isn't going to be remotely possible without order-of-magnitude improvements in battery technology. The economics of a 9 seater aircraft flying 30 minutes in what a car can cover in an hour is just terrible. Remember, that plane was flying slowly and didn't even climb over 2,500 feet. With no passenger load either, probably. The amount of energy it'd take to carry a load with passengers in a 30 to 1 hour flight at normal cruising speed is vastly greater than what is capable with batteries.
The existing lithium ion batteries are already approaching or exceeding 50%. Just like how there's only so much energy you can get out of a kilogram of gasoline, there's only so much energy you can store in a kilogram of a lithium battery (different chemistries like LiFePo have different thermodynamic limits, but they all have a hard physical limit). A battery powered plane would have to have a different battery chemistry, the thermodynamics of the best battery chemistry we know of is too constrained. "Pick a new chemistry" is way easier said than done. Why haven't we just picked a new combustible fuel chemistry that doesn't emit greenhouse gases?
And in a sense, you're right that battery powered planes are the future: hydrogen is that new battery chemistry. The energy density by mass and volume of compressed or liquid H2 is much greater than lithium batteries: https://en.m.wikipedia.org/wiki/Energy_density#/media/File%3...
First you read the chart wrong the volumetric energy density of compressed hydrogen is lower, liquid hydrogen had it’s own set of huge problems. Volumetric issues are huge for aircraft as larger volume means more drag which reduces the utility of all that energy.
Anyway, your comparing hydrogen ignoring the loss factor of engines, and the weight of fuel tanks so the useful energy density is much lower. “High-pressure tanks weigh much more than the hydrogen they can hold. The hydrogen may be around 5.7% of the total mass,[19] giving just 6.8 MJ per kg total mass for the LHV” At an overly generous hypothetical engine efficiency of * 50% that’s ~= 3.4 MJ per kg.
New chemistry is hardly a dream there are a huge range of battery chemistries out there with many under active development that beat current lithium ion batteries. Aluminum isn’t quite up to the hype, but it is very promising for aircraft.
> First you read the chart wrong the volumetric energy density of compressed hydrogen is lower,
No, you read the chart wrong: Hydrogen gas at atmospheric pressure - as in not compressed - has worse energy density by volume. Hydrogen at 700 bar has ~5x the energy per liter than lithium ion batteries at liquid hydrogen 10x. And all of these have energy densities by mass that are 100x better than lithium ion battery or more.
> New chemistry is hardly a dream there are a huge range of battery chemistries out there with many under active development that beat current lithium ion batteries.
Such as? You gave the example of aluminum, but as you point out they have problems that inhibit practical use: namely corrosion of electrolytes. The point remains: lithium ion is the best battery chemistry we've yet found and even it is far, far from up to the task of powering an aircraft.
