Sounds like you are sublimating/evaporating most of your sulphur?

Do a TGA after each step, sulphur is quite easy to detect

Dear Diez,

Can you mention the temperature at which you are drying your sulfur cathodes before introducing them to glove box, cell configuration with which you are working and electrolyte to sulfur ratio? One more important thing on which parameters you are performing your ball milling step?

for sure do TGA to correctly estimate the sulfur content! As highlighted by Ulissi may be you are subliming sulfur.

Regards.

I used to get the same results at 0.2C as well for a procedure similar to yours. There are a lot of factors that you have to ensure in order to get a nice results:

1] Make sure you have a good glovebox with clean Li [preferably wet your anode in some of the electrolyte for couple mins before assembling]

2] Make sure to prepare the EXACT electrolyte that is widely used in literature, (1M LITFSI in 0.2 M LiNO3]; preferably you should degass under heating both the LITFSI and LiNO3 at 120 C and 80 C for 2 days respectively. For the DOL and DME collect both of them under molecular sieves and leave them in GB for couple days

3] Do not accidently short circuit your 2032 coin cell. You have to work under non conducting circuit.

4] Run TGA to see the % of your sulfur, if you do not have enough sulfur, your capacity will suffer exponentially.

5] Drying your cast should be done overnight t 40-50 C using a DRYING VACUUM. Any moisture will not be good for your battery. Calendering is not required but optional.

I used to struggle to reproduce a paper in literature once to claim to get 1200 mAh/g at 0.2C. I got it in the end after taking into consideration all the above suggestion

Hope that helps!

I forget to mention that you should consider using 50 ml electrolyte /1g of sulfur as an electrolyte ratio. This will give you the highest value for capacity especially in the first cycles

Thank you very much for all your help. Thank you Ahmed for your detailed advice.

In my particular case, I was not loosing any sulfur during the drying. I finally got habitual values of capacity over 1200 mA h g-1 at 0.1C. To achieve such values I needed to do precycling (a couple of cycles) at a very low current density of C/20 prior to cycling at higher rates. Hope it helps as well to someone else struggling with these sulfur cathodes.