Stable cellulose-separator with CaO on nanoporous polypropylene by water-treated channels

Abstract

In this study, a stable battery separator was prepared to solve the thermal stability problem of lithium-ion batteries. A cellulose acetate (CA) and CaO composite solution was prepared, and a separator with improved stability was completed by coating it on polypropylene (PP). The added calcium oxide interacts with the carbonyl groups of CA to cause a crosslinking effect and at the same time to form the pores. By applying physical pressure based on water-molecules using a water treatment device, the pores of the two polymers (CA and PP) were partially connected, and interaction between the PP and the CA films was induced. The average water flux data and porosity for the separator were 208 L/m 2 h and 68.8%. The decomposition temperature increased by about 60 °C compared to pure CA. When this is used as a separator for a lithium-ion battery, its high porosity and thin thickness can enhance the charging efficiency and enable the fast lithium-ion movement. • Interconnection of cellulose separator with nanoporous polypropylene. • Enhanced stability by calcium oxide on polypropylene for separator. • Water-treated channels for interconnection through two polymers.