Cyclotriphosphonitrile-Based Electroactive Flame-Retardant Polymers for Electrochromic/Supercapacitor Devices

Abstract

To mitigate the thermal runaway issue and thereby enhance the safety of electrochemical energy storage devices, designing electro-active materials with intrinsic flame-retardant and thermal insulation functions is considered an effective way. Herein, we propose an innovative molecular design strategy that amalgamated the cyclotriphosphonitrile derivative HCTP-BTDPBr with a conjugated polymer framework to construct intrinsic flameretardant electro-active materials serving as dual function electrochromic/supercapacitor applications. Two series of donor−acceptor type copolymers, namely, PrOEG-BTD x -CTP y and PrOC 12 -BTD x -CTP y , were prepared by carefully modulating the ratio of HCTP-BTDPBr in the whole polymers. Systematic characterization of the electrochemical and flame-retardant performance revealed that PrOEG-BTD 0.82 -CTP 0.18 , PrOC 12 -BTD 0.46 -CTP 0.54 , and PrOC 12 -CTP showed obvious flame-retardant effects with the ignition times of 120, 108, and 80 s alongside heat release rates of 41.9, 27.5, and 31 KW m −2 g −1 , respectively. The high specific capacitance of 87.34 mF cm −2 (at 0.1 mA cm −2 ) was obtained from PrOEG-BTD 0.82 -CTP 0.18 . Meanwhile, those three copolymers showed excellent electrochromic performance with multiple color changes between blue/transparent, purple/gray, and red-orange/grass green and impressive coloration efficiencies of 258, 158, and 172 cm 2 C 1− , respectively. Thus, we believe this molecular design strategy has great potential to improve the safety of electrochemical energy storage devices.

Multifunctional Applications of D−π–A-Type Poly Schiff Bases for Electrochromic, Electrofluorochromic Materials, and Organic Cathodes for Aqueous Zinc Ion Batteries

“…The interest of researchers in investigating multifunctional conductive polymers was piqued by the rapid advancement of smart-technology methodologies. − Conductive polymer materials, such as electrode materials, electrochromic (EC) materials, electrofluorochromic (EFC) materials and devices, , energy-saving smart windows, − electromagnetic shielding materials, sensing materials, − and light-emitting diodes, − have been among the most discussed materials for the past few years due to their numerous practical applications.…”