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Comment by trhway | Hacker News Reader

>A new 2x battery technology seems unlikely.

i'd say giving the amount of money on the table, not only 2x, more like 10x is very likely. If you look at the actual amount of the lithium ions and actually participating oxidizer in the battery - it is 5% at best out of the total battery weight. So even modest progress at the decreasing of the weight of the "non-active" components would lead to multiple "x" of capacity/weight improve. And this is without even getting into metal-air territory.

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The money has been on the table for a long time (considering how many places lithium batteries are used in) yet still no considerable improvement. I really wish 10x energy density would be possible in the next few years, but 10x is definitely in the lithium/aluminium-air territory, and don't see any indication of that being commercialised within 2-3 years

If the last graph on this page is correct, then lithium batteries have seen at least a 2x improvement in all the important metrics since they've been introduced:

http://batteryuniversity.com/learn/article/battery_statistic...

(I'd be interested to see a graph that includes the last ten years....)

I'd call that a considerable improvement, albeit nowhere near 10x.

You are right, on average doubling every 10 years or so - I suppose that is considerable improvement, though still frustratingly slow compared to advances in transfer speeds, computing power, disk/memory capacity etc.

It would be fantastic if this was a problem where solutions are accelerated significantly (ie. 10x jump in a few years) by throwing more money at it, but I am not sure it's the case.

Here is a relevant Quora thread:

https://www.quora.com/Is-it-true-that-battery-energy-density...

Frustratingly slow considering how important batteries are, too. It's interesting to think about what would happen if you had some sort of magic battery, say a 1kg 10cm^3 cube that cost a dollar to make and held 1000kWh of energy. The changes would be huge. The electric grid would become vastly more efficient, wind and solar would suddenly become vastly more practical, virtually all cars would become electric, etc.

Compare to a similarly magic CPU. That would be cool, but it wouldn't change the world. (Until somebody figures out how to run superhuman AI on it, anyway.)

> a 1kg 10cm^3 cube that cost a dollar to make and held 1000kWh of energy

1MWh is 3600000000 or 3.6GJ. 3.6GJ/L is twice the energy density of Uranium, and 3.6GJ/kg is 40 times the specific energy (energy/mass). We wouldn't need a power grid anymore because we could just charge batteries on the moon and lob them to earth.

If we're in dreamland, we can just think about what'd happen with instantaneous subspace energy transmission. We could get rid of batteries and electrical grids altogether and we'd just turn the moon, mars and mercury into giant solar arrays. I'd wager that's more likely to happen than a 1L/1kg 3.6GJ battery too.

Turning the moon into giant solar arrays isn't useful because it's really expensive to put stuff up there and hard to maintain it, not because of the difficulty of transmitting the resulting power. I mean, it is difficult, but not that difficult. Even with magic power transmission technology, you'd be better off covering parts of the Earth with solar panels, rather than celestial bodies.

If you can essentially store unlimited energy, there is no need to "put stuff up there", you can just go and shuffle it around from the rest of the solar system. Putting it anywhere other than earth avoids further damaging the planet's ecosystems, and is a step towards the direct exploitation of the sun itself.

>> a 1kg 10cm^3 cube that cost a dollar to make and held 1000kWh of energy

>1MWh is 3600000000 or 3.6GJ. 3.6GJ/L is twice the energy density of Uranium, and 3.6GJ/kg is 40 times the specific energy (energy/mass). We wouldn't need a power grid anymore because we could just charge batteries on the moon and lob them to earth.

well, these densities is fusion energy. No need to charge at all. Just scoop up some He-3 on the moon :)

True, but looking at the trend in energy density improvements in Li ion batteries, it's linear and seems like it would take more than 2 years to achieve a 2x improvement: http://www.batteryuniversity.com/images/parttwo-55h.gif

The problem with reducing the mass of the non-Li portion of the battery is that all of the practical candidates for the anode are metal oxides (e.g. Co, Fe, Mn oxides). Unless the whole metal oxide motif is replaced, you can't really achieve significant mass savings. There are research groups and startups working on alternate anode and cathode materials but there are tradeoffs in power density and safety. Also given that these approaches are still in the research phase, it'll take at least a couple of years before they reach commercial testing.

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