This. We have electric engines pinned down. All that's missing from unlimited application of energy is better batteries and better power generation.
Look at it this way: Human endeavor consists of intelligent application of energy to mass. One of the three elements are close to being made trivial! It's very easy to get excited about batteries and renewable energy!
this is not that simple. the article claims that density is similar to lithium batteries, but it doesn't say what kind of density is it. the fact that it charges 20x as much may mean naught if it holds 1/20 energy per kg or per liter.
What do you mean "what kind of density"? "Similar to lithium batteries" means just that, if you have a lithium battery of a certain size, this will hold an amount of energy similar to that.
A 30% difference would still be classified as "similar", but this would still be a big deal since batteries are just borderline capable to provide electric cars with sufficient charge to be acceptable for most people. A battery that's 30% worse than the best current batteries would be unusable.
He's referring more to a car that could charge in 5 minutes and go 60 miles.
As I have an EV, that's closer to my current scenario of charging (once they put in a charger in the office parking lot) 4 hours and going 90 miles. The tradeoff of reduced distance for superior charge time is...irritating.
60 miles would be just short enough where I would need a gasoline car. That's why I've yet to get a Leaf. Can't afford a Tesla (nor do I want/need a car that big).
Energy density can be given in terms of mass or in terms of volume. In general, if a source of a new interesting battery technology does not describe which one they mean in a comparison, you can assume the worst, that is, that they are comparable to lithium-ion in joules/m^3 (at which lithium ion isn't actually that good).
Except that you also have to move the electricity into the car, which is actually the limiting factor in Teslas today, not the batteries. So this wouldn't really help at all.
From Tesla's website it looks like they take ~1 Hr to charge (1C rate). That would make me think they are limited by the maximum charge rate of the cells.
On the contrary, it is limited by the size of the cable going from the electricity distribution grid to the side of the car. With a typical (not a high performance) car engine capable of generating 75kW of mechanical power or so and a typical wall socket (in the UK at least) capable of transferring 3kW (and the average house having a 24kW total limit), there's going to be a problem that can only be solved by upgrading the cabling and using special high power sockets.
At some point the amount of copper needed to carry the current becomes heavier than the batteries themselves. 120kW is already outlandishly strong, at 120V it's 1000 amps!
If you had batteries which could accept that (Li-Ion's don't like going above 3C I think) and had the kind of energy density being claimed then it would be a relatively trivial matter to use a larger bank of them to provide the peak capability to charge a smaller bank of them.
Just read up on any existing quick-charging technology. Tesla's superchargers are the world's highest-capacity quick charging at 130kW, 2x the nearest competitor (CHAdeMO). And this still requires ~one hour to give the battery a full charge. Let's say you want to be able to charge in six minutes. That would mean something on the order of 1.3MW of electric power. So let's say you have a small-ish refueling station like a contemporary gas station, with eight charging spots. To power these, you need to pull ten megawatts from somewhere. The current power grid isn't dimensioned for this kind of demand, especially since the demand is very transient.
Tesla is attempting to solve this by building a massive battery storage capacity into the chargers and then trickle charging these batteries when the charging bays are not in use, so this is by no means a problem that has been solved once and for all.
Distribution level voltage is anywhere from 4kv to 25 kv. Say it's 12. Typical partridge or linnet distribution conductor might do 200 A. P=sqrt(3)IV cos theta = 1.73 * 200 * 12000 * 0.9 = 3.7 mw.
So you are correct your average distribution feeder probably does not have capacity for a 10 mw service. I guess that's not much of a shock.
In the United States the normal distribution voltage, prior to being stepped down for consumer use, 7.6kv phase to ground, 13.2 phase to phase. So yes, you're pretty close, except the 13.2 kv would be 3-phase. For heavy industrial use, 4.4 kv is common for actual end user equipment, but above that would be some pretty serious equipment for an end user. Larger transmission lines operate anywhere from 60kv on up to 1.1 million volts, so lots of power is possible, as long as you don't mind the brownouts.
AFAIK it currently takes ~20 minutes to half-charge a Tesla. 20x would mean charging fully in ~2 minutes - nearly as fast as the automatic option for replacing depleted batteries with fully charged ones.
> Charge profile is not linear in existing batteries. A supercharger is 40mn to 80% and 75mn to 100%.
Many people have a mental model of battery charging like a tank of gas or another fluid, in which the first 10% and the last 10% take the same amount of time and effort.
It seems like a better mental model of battery charging would be a pressurized container of a compressible gas: the more you put in, the more it takes to put the next bit in.
I don't believe it's known yet. Battery longevity seems to involve a lot of trial and error, and there isn't much data.
As far as I've been able to gather (and I have no real special knowledge here and could be way off), the main problem with quick charging is that it heats the batteries a lot, since charging is not a 100% efficient process and any waste energy turns into heat. Heat is bad for batteries, so it could affect their life. However, Teslas have active temperature management for their batteries (both heating and cooling, as required) which should mitigate that.
However, back in the days of NiCad batteries, some formulations could cope with really fast charges - and in fact would behave better and last longer after a very fast charge than they would after a slow charge.
We're talking about shoving 20 amps into a C cell for five minutes here. You needed to carefully monitor the cell temperature - the charging process wouldn't generate much heat until the cell was nearly full, at which point nearly all the energy going in would convert to heat. 20 amps would heat a full C cell up very quickly indeed.
