There is already a good answer that talks about how a catapult provides virtually no benefit for fuel-based aircraft.
However, I'm wondering if the same answer is true for electric planes? For example, I see here:
The high-lift [leading edge] propellers are all used during takeoff…. Once you get to a comfortable margin, say 30 percent above stall speed, then it will just run off the cruise [wingtip] props and you can fold the [blades on the] lift propellers.
This suggests to me that the aerodynamics, complexity, and weight of (at least that design of) electric aircraft could be improved if there were some other means of getting planes up to speed.
While a catapult is a pleasingly high tech solution, there are a number of reasons (some mentioned in that other answer) that make it impractical.
But what about some lower-tech options? A truck with a tow rope? A specially designed cart that the plane sits in that accelerates it up to take off velocity?
I know, that's not going to be practical for jumbo-jet sized craft. But for planes that seat (say) a dozen passengers, could this be a part of the solution? Or does the math work out essentially the same?
EDIT in response to GdD's question What problem are you trying to solve?
The biggest obstacles to adopting electric aircraft are the limitations imposed by today's battery technology. My question is intended to determine whether take off assist could address that limitation both by alleviating the high demand for power at take off, and by reducing the weight, complexity, etc of equipment that is only needed at take off.
So, the first part of the question is: Would any type of "take off assist" make useful contributions to the operation of electric airplanes?
Peter Kämpf's answer is "no" for existing aircraft. But does electric make things different? Especially given that electric airplanes are currently being designed from scratch?
The second part of the question is: Would any useful "take off assist" for electric planes be viable?
While a steam-powered, extended-length catapult might be both possible and beneficial (and cool), it's hard to believe it's ever going to be practical. But if a truck with a tow rope allows you to extend the plane's range by 25% while also reducing cost and maintenance, that seems interesting.
To address jamesqf's other comment, my target family of aircraft is something along the lines of Eviation's Alice.
I guess I'm just wondering if electric airplane designers are failing to consider it just because that's how existing planes work? Or have they done the math?