| 초록 |
A polyarylate (PAR) composite layer containing surface treated aluminum oxide was formed on a polyethylene (PE) separator to use as a separator for a large scale lithium ion secondary battery. A macroporous composite layer was formed onto microporous PE separator from coating solutions containing PAR, aluminum oxide as a filler, tetrahydrofuran as the solvent, and various diols as nonsolvents via a nonsolvent-induced phase separation process. The pore size increased with the molecular weight of the diol when the composition of the coating solution was fixed. It increased as the nonsolvent content in the coating solution increased, while it decreased as the PAR content in the coating solution increased. The meltdown temperature of the separator increased with the macroporous composite coating, while air permeability of the separator was reduced with the coating. Composite separator also exhibited better mechanical properties than PE separator. |
