In this work, cyanuric chloride is employed as the core element to react with polyetheramine in various ratios, and then chemical crosslinking with an organosilane, i.e., (3-isocyanatopropyl)triethoxysilane (ICPTES) to form a new organic-inorganic hybrid electrolyte with a core branched structure. The solid state of the hybrid electrolyte is fabricated via the doping of LiClO4 salt, and possessed the maximum ionic conductivity value of 1.1 × 10− 4 S cm− 1 at 30 °C and electrochemical stability window of around 5.0 V for the sample with the [O]/[Li] ratio of 32. The structure of the organic-inorganic hybrid is confirmed by FTIR and solid-state NMR measurements. The lithium ion mobility in the hybrid electrolyte is investigated by monitoring the lithium linewidths from static 7Li solid-state NMR. An optical density change value of 0.56 and an exceptionally high coloration efficiency value of 675 cm2 C− 1 with good cycle life are obtained when the present hybrid electrolyte is employed to fabricate the prototype electrochromic device. These electrochromic performances are the best as compared to the previously reported electrochromic devices made of hybrid electrolytes. The present organic-inorganic hybrid electrolyte holds great potentials to be used in different applications of electrochromic devices.