Company car tax is already drastically lower if you drive an electric car. From 6th April 2020 battery electric cars are now 0% BiK. This increases to just 1% post April 6th 2021 and 2% in 2022/23- that represents a massive saving over a conventional car.
https://www.kia.com/uk/electric-hybrid-cars/cost-of-electric-cars/

