Department for Transport figures show there were 1307 battery-electric vehicles in the Kingdom at the end of last year – up from 791 at the end of 2020, a 65% rise.
It meant 516 electric vehicles were newly registered in 2021 – double the 264 the year before.
The Government is aiming to entirely phase out petrol and diesel-powered cars by 2030, with battery electric vehicles planned to account for all car sales by 2035.
Auto Trader said the recent surge is positive, but that electric cars are still too expensive for many people to make the switch from petrol and diesel-powered vehicles.
Across the UK, the number of electric vehicles on the roads almost doubled, increasing by 94% from 215,000 at the end of 2020 to 420,000 last year.
On average, an electric car will emit around one-third less carbon dioxide than an equivalent petrol or diesel car, transport and the environment, a European clean transport campaign group, says.
Ian Plummer, commercial director at Auto Trader, said: "Over the last year, we’ve seen significant strides in range capability, as well as a growing choice of makes, models and body types, right now there’s one new electric vehicle coming onto the market per week."
He stressed the need to further invest in charging ports, saying drivers must have confidence in being able to charge their cars.
The Government hopes to install 300,000 public charging points by 2030, 18 times the number a decade previously.