We are trying to coat some cathode materials on Al-foil ( ex - LiFePO4 , S@CNT, etc). When we coated the Al foil with the cathode (ex - S@CNT) material , the cycling result was annoying. But the same Sulfur cathode was coated on Cu-foil, the result was satisfactory (except for obvious high voltage range > 3V). Same happens for other cathode materials also. We tried many thigs like drying the foil before coating in vacuum, and dry for longer time after coating. Nothing gave any improvrment in result.
What we noticed is, when doing CV for the S-cathode on Al, an irreversible reaction peak around 1 V was occurring. However this was not there for non-sulfur cathode like, LiFePO4 and Na3V2(PO4)3.
In the file attached below, the first one is when sulfur cathode is coated, and 2nd one is when NVP cathode is coated and worked for Li and Na battries respectively. all the corresponding electrolytes used were as usual as in the literature.
The coating composition was as usual as in literature - 80:10:10 material:CB:PVdF grinded with mortar and pestle for about 1.5 to 2h in NMP , with doctor blade technique with approx. loading of 1.5 to 2 mg/sqcm
What may be the problem..? please anybody explain this and give valuable suggetions.
where we are missing ? any additional steps should we follow , which in literature are not mentioned ?
Hi, with my very little experience, S based carbon materials actually often have this kind of problem what you mentioned. We were able to get rid of this when we coated the material on carbon coated Al foil. We did try different configuration and methods as you mentioned too. But carbon coated Al foil seems to work fine with S-based carbon materials. Hope it helps. At this moment I do not have much detail answers. But yes, keep us updated if things work out. Good luck.
Brinti Mondal Thank you so much for your valuable suggestions. We have also tried on the C - coated Al-foil (sinfle side C-coated - and we coated the material on the side where C is coated). but the result has no such satisfactory improvement . Rather almost same as the C non-coated Al-foil.
Also. we are not knowing the proper reasons for this characteristics.
well that is unfortunate. If you do not mind me asking, which type of cell set up you are using? i mean coin cell? Swagelok? For us, coating of carbon and applied pressure on the electrode was also a critical factor.
- Badges
- Science topic
- Similar topics
- Journal Impact Factor