Stabilization of gamma sulfur at room temperature to use in Li-S batteries
1–10 of 26 posts
Re: Stabilization of gamma sulfur at room temperature to use in Li-S batteries
#2The "notorious polysulfide shuttling effect" mentioned in the first sentence of the abstract is a pretty big understatement. It's basically an automatic death sentence for Li-S batteries in commercial applications, so the fact that this paper claims to have _zero_ polysulfide formation is pretty remarkable.
Short primer: The polysulfide shuttling effect is a phenomenon that can occur in lithium-sulfur batteries. It occurs when polysulfide ions, which are intermediates formed during the discharge and charging of the battery, are able to move from the cathode to the anode. This causes a decrease in the overall capacity of the battery.
To prevent this from happening, a separator with a high ionic resistance is used to physically block the movement of the polysulfides, but this increases the bulk and form factor of the battery, which makes it less suitable for applications like phones and laptops.
Re: Stabilization of gamma sulfur at room temperature to use in Li-S batteries
#3Other sources say 4000 cycles in one year of testing and the battery is still going strong. Apparently they used some chemical vapor deposition to dope sulfur in a carbon mesh, and apparently gamma sulfur was created in the process, which was accidental, they're trying to determine why their process created it.
Claim 3x the capacity of current lithium ion. That would be, what 600 wh/kg? 750? That seems unbelievable.
Re: Stabilization of gamma sulfur at room temperature to use in Li-S batteries
#4It's nice to see a battery chemistry article that admits they're in the early stages of getting some new chemistry to work. The usual battery article is "we got this to happen in a test tube, huge world-changing breakthough Real Soon Now". Those have become tiresome.
This article seems to have much less bullshit than most. Hope this one works.
Re: Stabilization of gamma sulfur at room temperature to use in Li-S batteries
#5It's nice to see a battery chemistry article that admits they're in the early stages of getting some new chemistry to work. The usual battery article is "we got this to happen in a test tube, huge world-changing breakthough Real Soon Now". Those have become tiresome. This article seems to have much less bullshit than most. Hope this one works.
It's an academic paper in Nature, it's not CNBC.
Re: Stabilization of gamma sulfur at room temperature to use in Li-S batteries
#6So they are claiming 800 mA-h per gram, which at 2.5V Li-S voltage gives about 7.2 megajoules per kilo, 1.5 the energy density of TNT.
Somehow I don't want to be anywhere near a battery with that kind of energy density.
Re: Stabilization of gamma sulfur at room temperature to use in Li-S batteries
#7Other sources say 4000 cycles in one year of testing and the battery is still going strong. Apparently they used some chemical vapor deposition to dope sulfur in a carbon mesh, and apparently gamma sulfur was created in the process, which was accidental, they're trying to determine why their process created it. Claim 3x the capacity of current lithium ion. That would be, what 600 wh/kg? 750? That seems unbelievable.
The energy density is the reason Li-S batteries are researched in the first place. Other prototypes of Li-S batteries according to Wikipedia already archived 450 Wh/kg.
Re: Stabilization of gamma sulfur at room temperature to use in Li-S batteries
#8So they are claiming 800 mA-h per gram, which at 2.5V Li-S voltage gives about 7.2 megajoules per kilo, 1.5 the energy density of TNT. Somehow I don't want to be anywhere near a battery with that kind of energy density.
Gasoline has 40 megajoules per kilo.
Re: Stabilization of gamma sulfur at room temperature to use in Li-S batteries
#9So they are claiming 800 mA-h per gram, which at 2.5V Li-S voltage gives about 7.2 megajoules per kilo, 1.5 the energy density of TNT. Somehow I don't want to be anywhere near a battery with that kind of energy density.
A quick search on Google: petrol megajoules
Petrol/gasoline 44-46 MJ/kg Diesel fuel 42-46 MJ/kg Crude oil 42-47 MJ/kg
You're already near far denser volatile chemicals, even if it isn't you driving someone else is somewhere.
Re: Stabilization of gamma sulfur at room temperature to use in Li-S batteries
#10So they are claiming 800 mA-h per gram, which at 2.5V Li-S voltage gives about 7.2 megajoules per kilo, 1.5 the energy density of TNT. Somehow I don't want to be anywhere near a battery with that kind of energy density.
Interesting. This lead me to this energy density table: https://en.wikipedia.org/wiki/Energy_density_Extended_Refere...