However, I have to agree that my previous comment _wrongly_ implied that burning coal at the plants to power the electric cars is the main issue we have to deal with.
I don't think it follows that just because we have historically centralized power generation, this was obviously due to efficiency. For example, centralization of management, investment, pollution control, logistical (fuel delivery), safety (nuclear) and reliability concerns seem far more obvious to me, although I don't doubt there could be an efficiency benefit to large-scale generation, I've just never heard of it.
Simple rectification has not so much loss, I think you are thinking about low voltage DC power supplies, and I think that chargers for large, high voltage battery piles are likely to be happy with rectified (maybe doubled) mains supply.
The low voltage supply is first rectifying the input, then using an inverter to generate high frequency AC, then rectifying and filtering this to give a DC output.
The simple "diode" rectification is no longer acceptable due to harmonics put on the AC side causing grid stability problems and emitted radio interference.
Citation needed. It seems obvious to me that a huge power plant is going to be less polluting per kWh than a tiny little engine in a car. Otherwise, we'd use tiny little car engines to power everything - which only happens at the moment in places where they cannot get electricity by other means (building sites etc).