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Scientists say new material can triple lithium-ion battery energy density

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Re: Scientists say new material can triple lithium-ion battery energy density

#81

Post by neltnerb »

mrfusion wrote: post #14

I always found it confusing that the lithium solution is most of the mass of the battery but all of the energy is in the anode and cathode.

The lithium is also in the anode and cathode, the electricity is generated by lithium traveling from one to another through the electrolyte. The electrolyte is heavier and bulkier but is picked for the ability to let lithium get through without letting electrons get through. I guess you could call it a lithium solution since lithium passes through it to get between the anode and cathode.

The anode and cathode need to be electrically insulated from one another requiring a substantial gap, or else the battery will short out internally or self-discharge if the electrical resistance is too low. That's why it's so big. Of course, reducing that gap is a big area of research. Solid electrolytes in principle might be easier to do this with since they stay put, but stuff cracks when lithium concentrations go up and down. The materials literally swell with lithium at the nanometer scale and then break apart. It's pretty hard, you can't unfortunately just vapor deposit a thin film of a solid electrolyte on the cathode since the materials are a bit too fragile to maintain the electrical resistance required for it to work.

Re: Scientists say new material can triple lithium-ion battery energy density

#82

Post by roryisok »

phyller wrote: post #67
roryisok wrote: post #64

Earlier quoted context omitted.

Petrol is fairly flammable and explosive too, but we still drive around with big tanks of it under the back seat

Gasoline is not explosive, it requires oxygen to burn. We wouldn't allow normal passenger vehicles to drive around with big tanks of explosives.

Yes, it requires oxygen, which happens to be all around and inside a vehicle typically. I'm not sure what your point is. If a fuel tank is ruptured it can lead to fire and/or explosion. If a battery is ruptured the risk of fire is a lot less. Maybe batteries carry a greater risk of spontaneously combusting, but I don't think that makes them more dangerous than carrying a tank of flammable liquid around

Re: Scientists say new material can triple lithium-ion battery energy density

#83

Post by thermodynthrway »

int_19h wrote: post #55
thermodynthrway wrote: post #51

Earlier quoted context omitted.

Sadly, it isn't remotely that good, closer to a change from C to AA. NiCad rechargeables have been around for over a century and LiPo only has a density about 3x higher. Overall we've only increased the energy density of the average rechargeable battery about 5x in a century, with most of the increase from introduction of NIMH then LiPo Improvements in power efficiency have made battery advancements seem better than…

I think most people are looking at flashlights for comparison, and LEDs were a massive leap in efficiency there. Didn't we make it all a great deal cheaper, though? I'm noticing lately that now even very cheap devices - the kind you can buy on eBay for a couple bucks - that used to be powered by AA batteries and such, are now coming with an integral lithium battery (and usually an integral micro-USB charger).

Batteries have definitely gotten way cheaper over the years, making them usable despite their marginal energy density in things like cars.

Re: Scientists say new material can triple lithium-ion battery energy density

#84

Post by FloatingVertex »

roryisok wrote: post #82
phyller wrote: post #67

Earlier quoted context omitted.

Gasoline is not explosive, it requires oxygen to burn. We wouldn't allow normal passenger vehicles to drive around with big tanks of explosives.

Yes, it requires oxygen, which happens to be all around and inside a vehicle typically. I'm not sure what your point is. If a fuel tank is ruptured it can lead to fire and/or explosion. If a battery is ruptured the risk of fire is a lot less. Maybe batteries carry a greater risk of spontaneously combusting, but I don't think that makes them more dangerous than carrying a tank of flammable liquid around

Petrol is very safe for the energy density it has due to the relatively slow rate at which outside oxygen gets fed into the flame causing a burn rather than explosion. TNT is far less energy dense (1/5 iirc) but because it contains oxygen it is far more dangerous and explosive. A very high energy density battery is likely to be closer to TNT in its reaction and not have the requirement of needing outside oxigen to keep the reaction speed in check (but really this depends on the exact technology of the battery)

Re: Scientists say new material can triple lithium-ion battery energy density

#85

Post by sitkack »

cutler wrote: post #72

Is it just me or have we been fed stories about potential improvements in battery life for over a decade now with no real improvements? There seems to be a vortex out in space where all these promises about CPU and battery improvements somehow get swallowed up. Take graphene, for example. Discovered in 2004, it was touted as something which was going to change the world and replace silicon in CPU production. Yet a re…

And there have been amazing incremental battery advances over the last decade.

Re: Scientists say new material can triple lithium-ion battery energy density

#86

Post by danjayh »

packet_nerd wrote: post #21
function_seven wrote: post #20

Earlier quoted context omitted.

Right. And if they don’t do that, then the phone will just get thinner. We already have incredible energy density compared to a decade ago, but that budget is used up by shaving millimeters off the thickness.

> used up by shaving millimeters off the thickness I wish they didn't do that, I would gladly carry around a slightly bigger phone if it had much better battery life.

I have an LG V20 with a 6700mAh battery. Goes for DAYS with moderate use, and will easily make it all day with extremely heavy use. I managed to kill it exactly once, with 4 hours of screen-on nav + steaming spotify, another 3 hours of youtube, and probably some misc usage. It's fantastic, and I keep wishing that somebody would release another phone with a user-replaceable (and upgradeable) battery so that I could move on. I actually bought this V20 after the V30 and S9 were out specifically for the removable battery. sigh, I blame apple.

Re: Scientists say new material can triple lithium-ion battery energy density

#87

Post by mathw »

princekolt wrote: post #75
cutler wrote: post #72

Is it just me or have we been fed stories about potential improvements in battery life for over a decade now with no real improvements? There seems to be a vortex out in space where all these promises about CPU and battery improvements somehow get swallowed up. Take graphene, for example. Discovered in 2004, it was touted as something which was going to change the world and replace silicon in CPU production. Yet a re…

Another thing to keep in mind: It makes no difference if battery capacity grows but power consumption goes up as well. When you have hungry apps (say, Chrome) hogging resources with no regard to the user's device, there is little to be gained from having denser batteries.

There is if those resources are being used to do more stuff... or you put the battery in a car.

Re: Scientists say new material can triple lithium-ion battery energy density

#88

Post by bdamm »

thermodynthrway wrote: post #51
bdamm wrote: post #45

Earlier quoted context omitted.

Well, the power of a battery the size of a brick in the 80’s is now available in a AA form factor. I’d say the improvement has been profound, if not quite as profound as Moore’s law is for CPUs.

Sadly, it isn't remotely that good, closer to a change from C to AA. NiCad rechargeables have been around for over a century and LiPo only has a density about 3x higher. Overall we've only increased the energy density of the average rechargeable battery about 5x in a century, with most of the increase from introduction of NIMH then LiPo Improvements in power efficiency have made battery advancements seem better than…

I was going by rated MAh comparing RC batteries from the 80's to the best (rechargeable!) AA battery I can find today. "A brick" might be overstating it, but 10x by volume isn't. It's more like 6 C down to 1 AA.
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