Combustion taxes makes sense if it's only used by transportation means, but that is not the case of electric energy. You could tax at the plug/socket level, but that's probably something that will be easy to tamper with.
There could always be something fancy such as remotely tracking the vehicles, but that will open a can of privacy worms.
The only viable option is to do tolls. Not necessarily representative of actual use, but a good enough approximation of use.