Polymer composite electrolytes containing ionically active mesoporous SiO2 particles

In exploring approaches to enhance ionic conductivity of solid polymer electrolytes, adding inert fillers has proved to be effective. In the present work, by doping ionically active SiO2 particles, which were designed by absorbing and confining liquid plasticizers in the nanosized pores of SBA-15 (a kind of mesoporous SiO2) to the polyethylene oxide (PEO)-LiClO4 matrix, about 10-fold further enhancement in the ionic conductivity was achieved as compared with adding inert SBA-15. The fillers dispersed homogenously in the PEO matrix. The ambient ionic conductivity reaches about 1.5×10−4 S cm−1 for (PEO)8-LiClO4∕10 wt % active SBA-15 films. Moreover, other properties such as the ambient lithium transference number, long-term stability of bulk and lithium metal electrode/electrolyte interfacial resistance, and the electrochemical window also showed good results. Application of such electrolytes in lithium batteries was asserted by cell testing with LiCoO2 cathode and lithium metal anode.