I think you'll struggle to find an electric car capable of that distance on a charge with a £15k budget. You could consider a plug-in hybrid – something like a Hyundai Ioniq PHEV will be able to cover local journeys under electric power, while having the back up of a petrol engine for your longer journeys. If most of your journeys are 160 miles, don't dismiss diesels – they'll be very efficient and make a lot of sense for this kind of mileage.