Charged Polymer-Coated Separators by Atmospheric Plasma-Induced Grafting for Lithium-Ion Batteries.
A simple and fast method of atmospheric plasma-induced grafting was applied over a polyethylene membrane to enhance its performance as a separator for lithium-ion batteries. The process of grafting has formed a thin, durable, and uniform layer on the surface of the porous membrane. The charges of grafted polymers affected the performance of batteries in many ways besides the change of hydrophilicity. Negative charges in polymers improve the capacity retention of batteries and the uniformity of the SEI layer. On the other hand, the electrostatic attraction between different charges contributed to small increases of thermal stability and mechanical strength of separators. Polyampholyte was grafted by using the mixtures of monomers, and the composition of the grafted layer was optimized. The formation of stable uniform SEI layers and the marked improvement in capacity retention were observed in the full cell tests of the lithium battery with the polyampholyte-grafted separators when the polyampholyte has a negative net charge.
Green Chemical Process Division, Korea Research Institute of Chemical Technology , Daejeon 34114, Republic of Korea.|Department of Chemical Engineering, Hanyang University , Seoul 04763, Republic of Korea.
Mina
M
Han
Department of Chemical Engineering, Hanyang University , Seoul 04763, Republic of Korea.
Dong-Won
DW
Kim
Green Chemical Process Division, Korea Research Institute of Chemical Technology , Daejeon 34114, Republic of Korea.
Yeong-Cheol
YC
Kim
Li-ion battery; grafting; plasma; polyampholyte; separator