In the quest of developing a sustainable, low-cost and
improved
separator membrane for application in energy storage devices like
lithium-ion batteries (LIBs) and supercapacitors (SCs), here we fabricated
a trilayer cellulose-based paper separator engineered with nano-BaTiO3 powder. A scalable fabrication process of the paper separator
was designed step-by-step by sizing with poly(vinylidene fluoride)
(PVDF), thereafter impregnating nano-BaTiO3 in the interlayer
using water-soluble styrene butadiene rubber (SBR) as the binder and
finally laminating the ceramic layer with a low-concentration SBR
solution. The fabricated separators showed excellent electrolyte wettability
(216–270%), quicker electrolyte saturation, increased mechanical
strength (43.96–50.15 MPa), and zero-dimensional shrinkage
up to 200 °C. The electrochemical cell comprising graphite|paper
separator|LiFePO4 showed comparable electrochemical performances
in terms of capacity retention at different current densities (0.05–0.8
mA/cm2) and long-term cycleability (300 cycles) with coulombic
efficiency >96%. The in-cell chemical stability as tested for 8
weeks
revealed a nominal change in bulk resistivity with no significant
morphological changes. The vertical burning test as performed on a
paper separator showed excellent flame-retardant property, a required
safety feature for separator materials. To examine the multidevice
compatibility, the paper separator was tested in supercapacitors,
delivering a comparable performance to that of a commercial separator.
The developed paper separator was also found to be compatible with
most of the commercial cathode materials such as LiFePO4, LiMn2O4, and NCM111.