There is no question that some useful short distance hops are possible in electrically-powered general aviation aircraft. Work is ongoing in human-carrying drones. Advances in high-power brushless DC motors, lithium polymer batteries, precision GPS and solid state inertial platforms make this possible.
However there is a huge difference between that and the air transport category. Most aviation energy is not consumed by general aviation or business aviation -- it is by commercial air transport. I don't know the exact numbers but I'd estimate over 90%, maybe over 95% is by commercial air transport, ie airline and cargo operations. Therefore any meaningful electric aviation solution must include that or at least articulate a plausible path using attainable technology to achieve electrically-powered commercial air transport.
The quote mentioned "short haul routes". To my knowledge this is routes under 3 hr, although some authorities use 3,200 km (1,727 nm).
What would be the energy or battery requirement for airline transport operations over (say) 1,500 km? Ideally this should provide roughly similar payload and travel time performance, else all of society is plunged back to the pre-jet era. Electric-driven jets are not really possible but electric-driven propellers are. Propeller-driven airliners with near jet performance have existed: the Tu-114 (based on the Tu-95). Fortunately its engines are rated in shaft horsepower which avoids the tricky conversion of pounds thrust to horsepower.
https://en.wikipedia.org/wiki/Tupolev_Tu-114
The Tu-114 had 4 x 14,800 hp engines. If we assume cruise power at 77% or 45,584 hp, that is 33.9 megawatts. A short-haul flight of two hours would therefore require roughly 67.8 megawatt-hours. How much battery power would be required to fulfill that?
33.9 MW is engine output, not including gearbox and propeller efficiency. To provide this electrically we must consider battery efficiency (say 90%) and electric motor efficiency (say 90%) for overall efficiency of 81%. We won't consider efficiency losses from motor controllers or other sources. This means the batteries must hold about 83.66 megawatt hours (not including reserves) for a two hr "short haul" flight of about 1,500 km.
The battery pack on an 85 KWhr Tesla Model S weighs about 540 kg (1,200 lb). We would need about 984 of these which would weigh about 1.18 million pounds. The Tu-114 had a payload of about 55,000 lb, but 130,000 lb of fuel for a total payload of 185,000 lb.
So very roughly, we only need an improvement in battery energy/weight ratio of about 10x to make this feasible. To recharge 10 of these after landing would require an on-site dedicated two gigawatt power plant, and the assumption each aircraft can sustain an approx 100-200 megawatt charge rate. Maybe Boeing's experience with the 787 li-ion batteries would give them an advantage.