With automobile technology working away from gasoline to batteries and talk of “battery technology improving rapidly”, I was wondering exactly how far battery technology could ever possibly get?
I’m aware that batteries don’t store electricity so much as they contain certain molecules and elements arranged just so as to create a chemical reaction which split the constituent elements into molecules with positive and negative charges (and, with rechargable batteries, can be reversed to restore things to their initial elements when a charge is applied.) From that, it would seem like really the only way to store more energy in your battery would be to pack as many atoms inside as possible and to come up with a reaction that didn’t gunk up the nodes/keep the nodes in the clearest areas of the muck as the charge runs out.
But anyways, what all can we expect, ignoring the difficulty in discovery of proper chemical reactions?
Is there some way to by-pass chemical reactions and really just stuff electrons and protons straight into some sort of holder?
That is exactly the function of an electrical capacitor. One disadvantage is that as you pump electrons in ( not a strictly accurate description) the voltage increases proportionally, and decays proportionally when you retrieve them.
In order to attain the energy storage density of even poor batteries, you have to resort to insanely high voltage, which is impractical (when not impossible) to utilize in motors and speed controls.
Perhaps I should ask the easier question of whether it seems feasible to get a battery-powered car’s battery down to (for instance) the size of a modern day car battery (under 1’ to a side)?
I first took the OP more literally, as raw “charge per volume”. In the science of aerosols (meaning particles suspended in air, not the more recent propellant product packaging for which Madison Avenue stole the name), there is a maximum charge per volume that is a strong function of the volume itself. When you exceed this, the mutual repulsion of the charge is stronger than the mechanical strength of the materiaol, and it explodes. It is also hard to keep something this strongly charged because of mechanisms that discharge it without it coming apart, such as free air ions and corona, but there’s always this charge-per-volume limit for all real solid and liquid substances based on their tensile strength.
In your bump you’re mixing the function of a current car’s battery (store enough energy to start the engine reliably) with the function of a current car’s fuel tank (store enough energy to push it 300 miles).
Producing an electrical storage device with the same energy density / capacity as a current gasoline tank is just out of reach.
Kevbo’s right that capacitors aren’t easy to use raw, but they are getting more amazing all the time, as is the interface electronics to take their wild power output & tame it for more mundane uses. See Supercapacitor - Wikipedia for an intro.
The big difference is that a 20 gallon gasoline tanks costs Toyota $15 plus $10 for the fuel pump. The corresponding capacitor & control system costs thousands, at least today, and will always be several orders of magnitude more complex & require higher-tech manufacturing, more precious materials, etc.
IANA ChemE, so I can’t speak to the theoretical limitations on chemical storage of electrical energy. Lots of money is invested every year in pushing the state of this art, so the practical limits today are right about what we see with laptops & cars like the Tesla: Batteries with power capacity equal to a 10 gallon gasoline tank take up the space of a 30 gallon fuel tank & weigh 2-3x what 30 gallons of fuel weigh.