Organic–inorganic hybrid polymer electrolytes based on polyether diamine, alkoxysilane, and trichlorotriazine: Synthesis, characterization, and electrochemical applications

Abstract

A new type of highly conductive organic–inorganic hybrid polymer electrolytes has been synthesized by the reaction of poly(propylene glycol)-block-poly(ethylene glycol)-block-poly(propylene glycol) bis(2-aminopropyl ether), 2,4,6-trichloro-1,3,5-triazine and alkoxysilane precursor 3-(glycidyloxypropyl)trimethoxysilane, followed by doping of LiClO4. The 13C and 29Si solid-sate NMR results confirm the successful synthesis of the organic–inorganic hybrid structure. The solid hybrid electrolyte thus obtained exhibits a maximum ionic conductivity of 1.6 × 10−4 S cm−1 at 30 °C, which is the highest among the organic–inorganic hybrid electrolytes. The hybrid electrolytes are electrochemically stable up to 4.2 V. The prototype electrochromic device with such a solid hybrid electrolyte demonstrates a good coloration efficiency value of 183 cm2 C−1 with a cycle life over 200 cycles. For the lithium-ion battery test, the salt free solid hybrid membrane is swelled with a LiPF6-containing electrolyte solution to reach an acceptable ionic conductivity value of 6.5 × 10−3 S cm−1 at 30 °C. The battery cell carries an initial discharge capacity of 100 mAh g−1 at 0.2C-rate and a coulombic efficiency of about 95% up to 30 cycles without the sign of cell failure. The present organic–inorganic hybrid electrolytes hold promise for applications in electrochromic devices and lithium ion batteries.