Mesoporous silica particles-embedded high performance separator for lithium-ion batteries

To improve the safety of lithium-ion batteries, poly(phenylene oxide)/mesoporous silica composite separator is facilely prepared by non-solvent induced phase separation wet-process and investigated in lithium-ion batteries (LIBs). Systematical investigations including morphology, porosity, electrolyte contact angle testing, electrolyte uptake/retention, and thermal shrinkage testing are carried out. The results demonstrate that the composite separator possesses notable features, such as uniform and porous surface morphology, symmetric interconnected porous structure all through the separator thickness. And owing to the relatively thermal-resistance constituents and well-developed microstructure, this separator shows superior thermal stability under 180 °C with little area shrinkage, higher electrolyte uptake/retention and ionic conductivity than the common polyethylene (PE) separator. Based on the above advantages, a cell with the as-prepared composite separator exhibits higher discharge capacity and better cycle property than that with a porous polyethylene separator. These results suggest that poly(phenylene oxide)/mesoporous silica composite separator is an effective separator for high performance LiBs.