This electric plane promises to fly 90 passengers 500 miles on a single charge

• Dutch startup Elysian unveiled plans for an electric plane it says could fly 500 miles on a single charge.
• The company says the E9X has eight engines and folding wingtips.
• Electric planes have largely failed to take off, with both NASA and Rolls Royce scrapping efforts.

After years of hype, electric planes have largely failed to get off the ground, with startups collapsing and existing prototypes struggling to take off.