Four types of Li1.5Al0.5Ge1.5(PO4)(3) (LAGP) with different particle sizes are selected as active fillers incorporated into polyethylene oxide (PEO) matrix to fabricate PEO/LAGP hybrid electrolytes at drying room. The results show that LAGP particles have a positive effect on the ionic conductivity, lithium ion transference number, electrochemical stabilities and mechanical properties. Among the PEO/LAGP hybrid electrolytes, the PEO-20%LAGP-I hybrid electrolyte exhibits a maximum ionic conductivity of 6.76 x 10(-4) S cm(-1) and an electrochemical window of 0-53 V at 60 degrees C. The possible reasons for conductivities improving are discussed through characterizing the phase transition behaviors of electrolytes. All-solid-state battery LiFePO4/Li is fabricated and presents fascinating electrochemical performance with high capacity retention (close to 90% after 50 cycles at 60 degrees C) and attractive capacities of 166, 155, 143 and 108 mAh g(-1) at current rates of 0.1, 0.2, 0.5 and 1 C, respectively. This work provides a promising PEO/IAGP hybrid electrolyte prepared by a simple method which can be manufactured easily in industry scale. (C) 2016 Elsevier B.V. All rights reserved.