Mesoporous silica (MCM-41) effect on (PEO + LiAsF6) solid polymer electrolyte

Composite polymer electrolyte films consisting of polyethylene oxide (PEO), LiAsF6 and mesoporous silica (MCM-41) with fixed PEO/LiAsF6 = 90/10 but different weight percent ratios of MCM-41 were prepared using the solution casting method. The polymer electrolyte films were characterized using XRD, DSC, SEM and electrical impedance spectroscopy. In corporation of MCM-41 in a (PEO + LiAsF6) polymer electrolyte facilitates salt dissociation, enhances ion conductivity, and improves miscibility between organic and inorganic moieties. The scanning electron microscopy (SEM) photographs indicates the electrolytes are miscible and homogeneous up to 10 wt.% of MCM-41, and an optimized conductivity is found at this composition (10 wt.%). However, at higher weight ratios (>10 wt.%), the Li/MCM-41-rich domain developed, and the conductivity decreased with increasing mesoporous material. The electrochemical performance of fabricated electrochemical cells of configuration Li/(PEO + LiAsF6 + MCM-41)/(MoO3 + C + PTFE) were investigated.