Figure 2. (a) ATR-FTIR spectroscopy and (b) XRD patterns of
cellulose and cellulose/CaCO3 membranes.
In order to study the effect of CaCO3 nanoparticles on
the thermal stability of cellulose porous membranes, thermogravimetric
tests were carried out on porous membranes, and the corresponding
results are listed in Figure 3 and Table 1 . As shown
in Figure 3a , the initial decomposition temperature did not
change regularly after the addition of CaCO3, probably
due to the absorption of water by cellulose with a large number of
hydroxyl groups. The maximum decomposition temperature increased with
the addition of CaCO3, from 351.3 °C to 355.7 °C and 356.7 °C
respectively, indicating that CaCO3 increases the
thermal stability of the cellulose membrane. Moreover, the residual mass
increased from 7.2% to 12.1% due to the decomposition temperature of
CaCO3 being greater than 700 °C.
As shown in Figure 3b , the commercial PP separator and the
cellulose-based membranes prepared in this work were subjected to 150 °C
and 180 °C for half an hour to evaluate the dimensional stability at
high temperature. The commercial PP separator shrank significantly and
can not maintain the initial round shape, and the shrinkage was severe
at 180 °C. In contrast, the cellulose and
cellulose/CaCO3 membranes can remain the original shape
even at high temperatures of 150 °C and 180 °C. Notably, excellent
dimensional stability is important to effectively prevent
short-circuiting when the battery is overheated. It can be predicted
that LIBs with cellulose/CaCO3 membranes would manifest
improved safety performance than that with commercial PP
separator.[38]