A series of cross-linked network solid polymer electrolytes based on dual end-functionalized polydimethylsiloxane bearing reactive thiol terminal groups with poly(ethylene glycol) diglycidyl ether and pentaerythritol tetrakis(3-mercaptopropionate) have been synthesized and characterized. The obtained results can be briefed as: ionic conductivity in the range of 1.5 × 10−6 S cm−1 at room temperature to 1.6 × 10−4 S cm−1 at 90 °C, lithium ion transference number ranged from 0.15 to 0.20, electrochemical window up to 5.3 V (vs. Li+/Li), thermal resistance (T d5 ca. 254.5 °C), and tensile strength (ca. 1.6 MPa at max.). The interplay taking place between structure and physico-electrochemical properties of in these systems based on merits of poly(ethylene glycol) moieties as high solvation matrix for Li+ ions flexible along with smooth solid support from polydimethylsiloxane allow the tailoring of the design of polymer electrolytes for future all-solid-state lithium batteries.