Neo... so whats on the horizon for batteries? Is it possible to make a reasonably sized battery that does cost/weight a ton, that will enable a car to do 400-500 miles?
It's a complex question, and it largely depends what you mean by reasonably sized - but, to put it very bluntly, in the next ten years, with the physics we know, probably not.
Let me clarify - battery technology (referring to the electrochemical and the electromechanical aspects) will improve by some percentage each year, but it is not a large percentage. What this means is, in 5-10 years:
1. You can pay the same amount for a battery pack of the same mass and get double the range of the EVs on sale today.
2. You can pay half the amount for a battery pack of hall the mass and get the same range of the EVs on sale today.
There will be other savings associated with economies of scale and organisation of infrastructure and so on, so in real terms the battery pack will end up costing less, no matter what. In any case, amongst most of the car companies pursuing an EV option, option 2. is preferred as it better suits the use case for an EV and helps drive down cost, and so on. It also improves the dynamics and efficiency of a vehicle (less heavy battery pack results in less mass to lug around, hence an improvement in efficiency).
The problem with a metal-based battery is that, as I mentioned, its energy density compared to gasoline is poor, and there's simply no way around that (hell,
wood has a greater potential energy than metal, but the conversion effiency - how efficiently you can convert the chemical energy stored within to kinetic energy - is so poor rendering such an exercise pointless). So an EV for very-long ranges just doesn't make sense, especially as you take energy out of the battery pack, you still have the same mass to lug around, resulting in an overall decrease in vehicle efficiency.
For longer-range vehicles
at the moment gasoline-electric is the way to go, be it parallel hybrid (a Prius - a normal car with a small gasoline engine with electric "assist") or a series hybrid* (petrol engine used as a generator to recharge the battery pack - vehicle is electric drive only - what my company works on).
It is interesting to note, that our favourite car company (Volkswagen), recently announced what I believe is probably the most sensible policy of any auto company - that they will not be pursuing EVs, but instead will offer a plug-in hybrid of one kind or another (that is, a parallel or series hybrid which can have the battery pack recharged from the mains for limited electric-only drive) for every single model in its line up.
*Also worth noting that the term "series hybrid" technically encompasses hydrogen fuel cell cars. Problem is between the likes of Clarkson and the PR firms of all of these auto companies it's a bit of a nonsense trying to work out what is what, with terms like "fuel cell vehicle - FCV" and "Range extended EV - REEV" and toyota's abysmal "Full hybrid" (?!) all essentially meaningless.
