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Batteries with 50 per cent more energy with pure silicon anode

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Re: Batteries with 50 per cent more energy with pure silicon anode

#41

Post by [deleted] »

jandrese wrote: post #33
hwillis wrote: post #18

Earlier quoted context omitted.

>Even with the precipitous drop in solar cell prices over the past few years they still aren't cheap. By what metric..? The amount of energy and power involved in the two uses is completely different. Do you happen to know the bulk cost of silicon, or how much silicon is used in solar cells, or how much of a solar cells cost it makes up, or what process is similar? You're not doing much more than a kind of free assoc…

The article states outright that they think they can make it to market quickly by leveraging Solar Cell production facilities. The bulk cost of silicon is a moot point. That's like asking how Pizzas can be made more cheaply if you reduce the cost of the flour involved. It's the extreme precision ultra pure processing that makes it expensive, not the bulk materials.

[deleted]

Re: Batteries with 50 per cent more energy with pure silicon anode

#42

Post by hwillis »

csours wrote: post #28
hwillis wrote: post #10

Silicon has been used in batteries for several years now in low amounts. It hasn't seen larger use because it expands by 400% when filled, compared to graphite's ~12% expansion. Most attempts to solve this have been extremely complicated; nanopatterning, nanowires, graphene coatings to literally compress the silicon metal, etc. It's one of the most promising avenues for battery tech (silicon anodes alone may be able…

> Commercial cells have 500-800 cycles in their lifetime (until their capacity falls to 80%) What does this mean? I feel like I charge my phone more than 500-800 times.

Under standard test conditions. That means 100% depth of rated discharge at a set speed (between 1 and .1 C, ie fully charged/discharged in 1-10 hours) and temperature.

Cycle life increases dramatically at lower depth of discharge, so if you normally recharge your phone when it gets to 10% it'll last twice as many cycles. High temperature and fast discharges will reduce that.

Essentially your phone is rated to be driven to 0% once a day for ~2 years, give or take a bit. Less if it gets hot, which it will, because the battery is used as a heatsink for the rest of the phone.

Re: Batteries with 50 per cent more energy with pure silicon anode

#43

Post by Nition »

rconti wrote: post #27
Bud wrote: post #26

This article, and this comment thread, both seem to be ignoring what is actually in the way of any "50% more energy" battery tech being used in consumer laptops: FAA regulations limit all such batteries to 100 watt/hrs or less. It's not Apple, it's not Samsung...they have no choice. So until we get over our stupid post-9/11 policies, it doesn't matter if Star Trek batteries magically spring into existence. The tech i…

That's fine. Laptops can keep getting more efficient. This tech can be used for cars and home storage and.. basically everything except devices like laptops that are on that 100w/h boundary. Already, laptops suffice for most flights. Then, eventually, this regulation will go away.

Have a high-capacity laptop battery for normal use and a cheap, lower capacity 100Wh one you can swap in to take on flights.

Re: Batteries with 50 per cent more energy with pure silicon anode

#44

Post by hwillis »

woodandsteel wrote: post #34
hwillis wrote: post #10

Silicon has been used in batteries for several years now in low amounts. It hasn't seen larger use because it expands by 400% when filled, compared to graphite's ~12% expansion. Most attempts to solve this have been extremely complicated; nanopatterning, nanowires, graphene coatings to literally compress the silicon metal, etc. It's one of the most promising avenues for battery tech (silicon anodes alone may be able…

Could you explain what a pouch cell is? Is it the same as the battery in a cell phone or laptop? Why does it matter for this development that it's a pouch cell rather than some other type?

Cell phones use pouch batteries, aka prismatic cells. Laptops almost all use 18650 cells, which are cylindrical and look a lot like very large AA batteries.

Coin cells are just really simple. They're pretty standard for proving your battery works. The thing is that there is a huge difference between that and a real useful battery. You can pay a grad student overtime to build a coin cell of about anything. You need a machine to make a pouch cell.

It's like if someone showed you a go-kart and said they could make a car. They share the same elements and everything, but there's a definite world of difference between them. It's a lot more than just being bigger.

Re: Batteries with 50 per cent more energy with pure silicon anode

#45

Post by hwillis »

tmaly wrote: post #21

Does this still need lithium?

Of course. Lithium is the third lightest element and nearly the most electronegative (ie it has a high voltage). It's the best battery material you could possibly pick! Not to mention, it's absurdly cheap and incredibly common. Lithium makes up <1% of the cost of a battery.

Re: Batteries with 50 per cent more energy with pure silicon anode

#46

Post by ChuckMcM »

Bud wrote: post #26

This article, and this comment thread, both seem to be ignoring what is actually in the way of any "50% more energy" battery tech being used in consumer laptops: FAA regulations limit all such batteries to 100 watt/hrs or less. It's not Apple, it's not Samsung...they have no choice. So until we get over our stupid post-9/11 policies, it doesn't matter if Star Trek batteries magically spring into existence. The tech i…

Sorry but I have to disagree. While the limit is important for appliance electronics like laptops it doesn't have any impact at all on electric vehicles which are all mostly LiOn powered. 50% more range or 50% less weight would be an interesting change to put in the mix at Tesla for example.

If you look at where batteries are going to be in volume in the next 20 years it will be in grid storage, off-grid house energy storage, vehicles, and potentially small industrial tools.

Of course if this particular breakthrough actually makes it into batteries we will all be pleasantly surprised, as battery "breakthroughs" have a success rate quite a bit lower than 'venture funded startups' :-)

Re: Batteries with 50 per cent more energy with pure silicon anode

#47

Post by davesque »

hwillis wrote: post #45
tmaly wrote: post #21

Does this still need lithium?

Of course. Lithium is the third lightest element and nearly the most electronegative (ie it has a high voltage). It's the best battery material you could possibly pick! Not to mention, it's absurdly cheap and incredibly common. Lithium makes up <1% of the cost of a battery.

Is it really that common? I was under the impression that it's somewhat scarce and, furthermore, a large amount of Lithium deposits reside in regions of relative political instability:

https://www.economist.com/blogs/graphicdetail/2017/06/daily-...

Re: Batteries with 50 per cent more energy with pure silicon anode

#48

Post by maxharris »

mitchty wrote: post #37
jpm_sd wrote: post #30

Earlier quoted context omitted.

Those rules have nothing to do with 9/11, they are based on risk of fire due to manufacturing defects.

That and limiting the amount of energy that could be released if there is a defect. I don't think i'd want a 1Kwh battery on a plane.

I have never seen a laptop catch fire, on a plane or otherwise. While I have seen a few stories that report fires here and there, I really don't think this is a big issue, and I'd feel comfortable riding on a plane with lots of 1kWh batteries on it.

Re: Batteries with 50 per cent more energy with pure silicon anode

#49

Post by maxharris »

mitchty wrote: post #37
jpm_sd wrote: post #30

Earlier quoted context omitted.

Those rules have nothing to do with 9/11, they are based on risk of fire due to manufacturing defects.

That and limiting the amount of energy that could be released if there is a defect. I don't think i'd want a 1Kwh battery on a plane.

http://www.ehang.com/ehang184

This thing might blew my mind. It's a battery-powered drone that you can fly in!

I don't know exactly how big the battery is, but my best guess is that it's bigger than 1Kwh...

It's not vaporware either. There are lots of videos of this thing flying!

Re: Batteries with 50 per cent more energy with pure silicon anode

#50

Post by hwillis »

davesque wrote: post #47
hwillis wrote: post #45

Earlier quoted context omitted.

Of course. Lithium is the third lightest element and nearly the most electronegative (ie it has a high voltage). It's the best battery material you could possibly pick! Not to mention, it's absurdly cheap and incredibly common. Lithium makes up <1% of the cost of a battery.

Is it really that common? I was under the impression that it's somewhat scarce and, furthermore, a large amount of Lithium deposits reside in regions of relative political instability: https://www.economist.com/blogs/graphicdetail/2017/06/daily-...

It's more common in the crust than lead, the second most common battery type, and uses ~100x less per kWh than lead acid batteries do.

Lithium is very poorly mapped. The last time the USGS surveyed it was in the 50s IIRC. For instance, that article is wildly inaccurate. It lists 6.9 million tonnes in the US. A single site, 45 miles to a side, in wyoming is estimated at up to 18 million tonnes of lithium[1]. Then again America may also count as a region of relative political instability.

I'll point out though that if you're gonna bring up political instability, around 20x (up to 60x in cellphones) as much cobalt is used in batteries as lithium, and virtually all of that comes from a single country: Congo. That's political instability. Lithium is a cakewalk by comparison, and fears about it are just manufactured and overblown.

[1] https://oilprice.com/Energy/Energy-General/New-Wyoming-Lithi...

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