Elon Musk has said advances in battery technology could make electric planes commercially viable within three years.

The Tesla boss made the claim just two weeks after the electric car maker published a research paper detailing vastly improved next-generation battery cells.

The breakthrough appears to have prompted Musk to revise a previous prediction from 2019 that it would be at least five years until commercial batteries achieve a 400Wh/kg energy density, which he calculated is necessary for flight.

“400 Wh/kg *with* high cycle life, produced in volume (not just a lab) is not far,” he tweeted. “Probably 3 to 4 years.”

Several companies are already working on zero-emission planes, though Tesla is yet to commit to building one.

Musk has hinted several times that he is interested in creating one, even as far back as 2010 during his one-line cameo in Iron Man 2. “Got an idea for an electric jet,” he said.

In a 2016 interview he revealed that he already had prototype designs for a vertical take-off vehicle, though they have never been publicly released. In an interview two years later he said Tesla’s focus remained on cars, claiming that developing an electric plane “isn’t necessary right now”.

Small-scale operations are already underway, with the first ever commercial test flight with an electric plane taking place last year in Canada.

Harbour Air flew an electric seaplane for 15 minutes over the Fraser River, in what could be the first step towards electrifying its entire fleet of more than 40 planes.

Tesla did not immediately respond to a request for comment from The Independent.