Abstract:
This study features comprehensive physical and electrochemical properties of different polyolefin and non polyolefin separators. These separators include polypropylene-polyethylene-polypropylene (PEP), polyethylene
(PE), Al2O3-coated polypropylene (C-PP), polyethylene terephthalate (PET), and Silicon carbide mat (SiCmat).
The interaction of the different separators and the electrolyte was investigated in terms of ionic conductivity,
contact angle test, electrolyte uptake, and electrolyte oxidation. The full cells fabricated using the different
separators were also studied for charge–discharge performance, cycle performance, and internal resistance.
Results showed that the different separators demonstrated different physical and electrochemical behavior. The
non-polyolefin separators registered a small electrolyte contact angle due to their high porosity and structural
compatibility with the electrolyte. At 10 C-Rate, the specific capacity is in the order of PET > SiCmat > C-PP >
PE > PEP corresponding to 90 mAh/g, 85 mAh/g, 70 mAh/g, 60 mAh/g and 40 mAh/g respectively. After 100
cycles at 1.0 C-rate, the cycle performance is in the order of PE > PET > C-PP > SiCmat > PEP corresponding to
70 %, 65 %, 61 %, 51 % and 49 % respectively. Thermally, PET, C-PP and SiCmat showed better thermal stability
compared to the other separators. Therefore, Industrial production that requires high thermal stability may rely
on C-PP, PET, or SiCmat, while PET and SiCmat offer better cycle performance and may replace commercially
available PE and PEP.
