Composites of Li1.3Al0.3Ti1.7(PO4)(3) (LATP) with Li+ ion containing polymer polyethylene oxide (PEO), viz. 5LiCF(3)SO(3)-95[PEO(1-x)LATP(x)], are prepared in a wide composition range (0 <= x <= 0.7). A maximum conductivity of similar to 10(-4) omega(-1) cm(-1) at 45 degrees C has been achieved for a composition x = 0.7 (70 LATP). With increase in LATP content, Li+ ion transport number systematically increases, i.e., from similar to 0.12 for 0 LATP to 0.46 for 70 LATP. Ionic mobility also exhibits a gradual rise with LATP content and attains a value similar to 2 orders of magnitude higher for 70 LATP than 0 LATP. Further, the K-edge energy of ether oxygen, obtained from X-ray absorption near-edge structure spectra, does emphasize decoupling of Li+ ions from PEO matrix, particularly for large LATP content. Our investigations suggest that such hybrid films are competitive candidates for solid ionic devices. All-solid-state supercapacitors fabricated using these films demonstrate a capacity of similar to 2-4 F-g(-1).