With current batteries, there are just many tiny 18650 cells connected in parallel / series to get the desired power and voltage, right? Are you saying there are some unstated engineering limitations that would hinder getting to the desired "C" by connecting more battery cells in parallel?
When connected in parallel, each cell has to discharge at same rate within a small margin. That means you have to match cells by capacity and internal resistance during manufacturing process. The more cells you put in parallel, the more chance some of them will age differently and cause whole battery to underperform or fail spectacularly.
And why the batteries have to discharge at the same rate in the first place?
That said this is a problem with all batteries which is solved trough rebalancing: https://en.m.wikipedia.org/wiki/Battery_balancing
Without this we wouldn’t ba able to make battery packs with 100s not to mention 1000s of cells and even smaller battery packs would die much much sooner.
A good analogy would be if you have a boat with multiple people rowing and one of them can’t hold the same pace if you don’t adjust for it you aren’t going to hold course and if you don’t let the man catch a break they’ll pass completely eventually.
It's the definition of the cells being in parallel. Since they all have the same voltage difference (as the fronts and backs are all tied together with wire), they have to discharge at the same rate. The balancing dogma1138 was describing is done to allow some batteries to run at slightly different voltages so they all are at around the same state of charge.
Two batteries in parallel have the same C rating! You double the output current, but you also double the capacity. When you put cells in series, you change the voltage but the current capability and capacity stay the same. In both cases the C rating doesn't change[1].
The C rating is just how quickly the battery can discharge itself, so it is entirely dependent on the chemistry and battery conditions.
[1]: there are finer points; more batteries in series lowers output current slightly in practice, and batteries in parallel are quite complex to deal with. Cell size, construction and cooling all have large impacts on the C rating as well but at the end of the day it's simply how quickly a square centimeter of battery material can carry out its chemical reaction safely.
>But the battery only functions properly at temperatures above room temperature and up to 150°C
It doesn't have to be over 150 Celsius, it has to be over room temperature.
There aren't really any perfect solutions, but cold temperatures are a problem we've dealt from the beginning with both batteries and internal combustion engines. My dad used to tell me stories about his time in Alaska as a teenager, and a bush pilot who would talk about when he'd have to pull the drain the oil from his plane, pull the battery, and take both inside overnight to keep them from freezing.
0. http://popularmechanics.com/cars/hybrid-electric/a21999984/e...
That isn't the standard, at least not in North America (120V/240V) or Europe (230V):
I am not sure where it comes from but in the US it's not uncommon for supplies to be referred to as 220/110 rather than 240/120. They're generally understood to be the same thing.
Interesting fact: Tesla achieves their ludicrous mode (2.3 seconds 0-100kph) by pre-heating their batteries so that more power can be drawn. During my test drive, it took an estimated 40 minutes to heat the batteries to do this...
Thanks!
According to [1], the specific energy is ~300 Wh/kg- the best li ion cells are ~275 Wh/kg, but only barely. When the OP article refers to 2-3x capacity improvements (2x on the website), it refers to energy density, or Wh per liter. That's not really considered an important metric except for phones. Unfortunately, the battery has to be over 150 Celcius for the solid electrolyte to work, so don't expect better phone batteries any time soon.
The way this would work is that cars would have a small conventional battery of ~15-30 kWh that could supply acceleration power and preheat the solid state battery. The larger battery would just back it up on long trips. How attractive this is depends 100% on how much power they can crank in the battery, since it isn't that much bigger than a normal battery.
Lots of people think solid state batteries will eventually replace liquid electrolytes, but it's effectively anyone's guess. We've had a lot of trouble finding high-power solid electrolytes for a looong time. The main benefits are safety related right now.
The basic reason is that conventional cathodes are highly oxidizing, so when a liquid electrolyte gets too hot it steals that oxygen and breaks down, causing a runaway reaction. Solid electrolytes and metallic cathodes don't have extra potential energy, so when there's damage to the cell like a short or overtemperature it simply burns itself out. The solid electrolyte is also far more stable and isn't very subject to breakdown from overtemperature or overvoltage.
[1]: https://qz.com/1383884/a-startup-promising-an-all-solid-stat...