Elon Musk has said he is “dying” to expand beyond cars and trucks with Tesla and build an electric supersonic jet.

The planes would use vertical take-off and landing (VTOL) technology to rise to a high altitude, before using battery-powered propulsion to reach speeds in excess of 1,236km/h (768mph).

The polymath billionaire said the only thing stopping him from developing the next-generation aircraft is his current workload.

Mr Musk currently heads two multi-billion dollar companies – SpaceX and Tesla – as well as neurotech startup Neuralink and tunnel-digging venture The Boring Company. He is also the co-founder of the artificial intelligence research laboratory OpenAI and the father of six children.

“I’m so dying to do a supersonic, electric VOTL [sic] jet, but adding more work will make my brain explode,” he tweeted on Thursday, using emojis for the final two words.

It is not the first time Mr Musk has spoken of his ambition to design an electric jet, having previously detailed a concept during one of his appearances on the Joe Rogan podcast.

“I have a design for a plane,” he said. “The exciting thing to do would be some kind of electric vertical takeoff and landing, supersonic jet.”

The concept would use two different propulsion systems: one to lift the plane off the crowd and into the sky, the other to propel the craft forward at supersonic speeds.

“The interesting thing about an electric plane is that you want to go as high as possible but you need a certain energy density in the battery pack because you have to overcome gravitational potential energy,” he said.

“Once you’ve overcome gravitational potential energy and you’re at a high altitude, the energy you use in cruise is very low, and then you can recapture a large part of your gravitational potential energy on the way down.

“The higher you go, the faster you will go for the same amount of energy. And at a certain altitude you can go supersonic with less energy-per-mile – quite a lot less energy per mile – than aircraft at 35,000 feet.”

In 2013, Mr Musk came up with another idea for a new forms of transport called the Hyperloop. Without the capacity to work on it himself, he wrote a whitepaper for the 1,000kph vacuum tube pods, which other startups then used to develop their own versions of it.

Mr Musk subsequently funded competitions to encourage its development, with the hope that Hyperloop networks could provide an eco-friendly and more efficient alternative to plane travel.