Effect of nanoclay on properties of porous PVdF membranes
(1. School of Materials Science and Engineering, Engineering Research Institute, i-Cube Center,
Gyeongsang National University, Jinju 660-701, Korea;
2. Fuel Cell Research Center, Korea Institute of Science and Technology, Seoul 136-791, Korea;
3. Energy Material Research Center, Korea Research Institute of Chemical Technology, Daejeon 305-600, Korea)
Gyeongsang National University, Jinju 660-701, Korea;
2. Fuel Cell Research Center, Korea Institute of Science and Technology, Seoul 136-791, Korea;
3. Energy Material Research Center, Korea Research Institute of Chemical Technology, Daejeon 305-600, Korea)
Abstract: The main requirements for battery separators are high porosity which can serve pathways of lithium ion and space for gel electrolytes to impregnate in a membrane and mechanical strength to allow easy handling for battery assembly. Generally, it appears the trade-off relationship between the porosity and mechanical strength of the membrane. PVdF composite membranes containing nano-size clays were used to improve the mechanical strength of the membrane without affecting the membrane porosity. The composite membranes were prepared by phase inversion method controlling the membrane preparation conditions such as retention time. The resultant membranes show increased mechanical properties with similar membrane porosity around 80 % compared to the pristine PVdF membrane. Incorporation of nonoclay can be considered as an effective method to improve the mechanical strength in porous membrane supports, especially in a separator.
Key words: Li-ion battery; separator; poly(vinylidene fluoride); nanocomposite