Other chemistries that have potential further down the line are sodium ion, which is benign and sustainable, semi-solid state and solid state, “but solid state is still a costly route”, warns Palmer. Technical improvements will also help to boost efficiency and lead to smaller batteries.
“The best possible cooling is important,” he adds. “Keeping the temperature between the coolest cell and the hottest cell within points of a degree prevents cell decay. Also integration of the pack and finally electronics. If you bring these things together, you can make batteries more efficient and therefore cheaper. But ultimately, the big move comes by having a widespread network that allows you to have smaller batteries.”
David Greenwood, an advanced propulsion systems expert at the Warwick Manufacturing Group, explains that there’s more to the cost of an EV than just the purchase price.
“When we’re talking about cost, what do we mean? Is it just purchase cost? Is it whole-life cost? Aspects of the vehicles and vehicle design have a bearing on cost but so does charging infrastructure,” says Greenwood. “There’s also the question of whether batteries can be made more cheaply, but that’s the last thing in the chain.”
With EVs, the total cost of ownership is arguably a more significant consideration than for conventional cars, says Greenwood. “For people buying the ‘right’ EV – by which I mean the owner is using the range it’s capable of – the total cost of ownership is not a big issue,” he says.
“If you’re clever about which tariff you get from your provider and store the energy you buy in the car’s battery, then your total cost of ownership is at least as good as it is for a petrol or diesel car. The challenge is the really big upfront cost, but running costs afterwards are pretty low.”
Finance packages such as leasing and PCP help to lessen the impact of the upfront cost, and when combined with the lower ‘fuel’ and servicing costs, adds Greenwood, “overall you should still be winning.