Low-Cost and Heat-Resistant Poly(catechol/polyamine)-Silica Composite Membrane for High-Performance Lithium-Ion Batteries

Graphical Take a dip : A composite membrane based on SiO 2 and a low-cost poly(catechol/polyamine) (PCPA) multicomponent system is prepared by using a simple dip-coating process. The resulting membrane exhibits excellent thermal stability and wettability. A composite membrane based on SiO 2 and a low-cost poly(catechol/polyamine) (PCPA) multicomponent system was prepared by using a simple dip-coating processes. The results indicate that the formation of an inorganic/organic composite coating on the surface of the polyethylene (PE) separator is beneficial for improving the comprehensive performance, especially for the thermal stability and wettability. Compared to the PE separator, the thermal stability of the PE@SiO 2 -PCPA composite membrane is greatly improved, showing a higher decomposition temperature (426 °C) and a smaller heat shrinkage rate at 160 °C. Moreover, the Li/LiCoO 2 battery assembled with the PE@SiO 2 -PCPA composite membrane shows an excellent initial discharge capacity and a remarkable capacity retention (171.5 mAh g −1 , 86.1 %) at 4.4 V after 200 cycles at 0.5 C, which much higher than the PE membrane (165.2 mAh g −1 , 61.4 %). This study provides a potential application for membranes with low cost, high thermal stability, and good wettability in the field of lithium-ion batteries.