Electrical And Energy Storage Properties Of Spirobifluorene-based Conjugated Microporous Polymers And Derived Porous Carbons

Conjugated microporous polymers(CMPs)have been widely used in supercapacitors and phase change heat storage fields due to their advantages such as high specific surface area,adjustable pores,and easy functional modification.In this paper,a new type of spirodifluorene/aniline conjugated microporous polymer,and multiarmed carbon nanotube composite and pyrolytically derived porous carbon materials are prepared,charactering them physical and chemical structures,exploring them effects on electrochemical energy and heat store applications.This article will be mainly introduced through the following three parts.(1)the paper proposes the Buchwald-Hartwig coupling to solve the problem that the traditional C-C coupling method of conjugated microporous polymers is difficult to introduce functional groups on the polymer main chain.A new imino-functionalized spirobifluorene/aniline conjugated microporous polymers(SACMP)is prepared by optimizing the reaction solvent,and confirming them chemical structure by FT-IR,¹³C NMR,and XRD.The results shown that the specific surface areas of SACMPs prepared in toluene,tetrahydrofuran,and toluene:tetrahydrofuran(1:1)solvents can reach 341 m²/g,660 m²/g and 479 m²/g,respectively.SACMPs show good adsorption performance for carbon dioxide,and maximum adsorption capacity reach 105.4 mg/g at 273 K.In addition,the assembly of SACMPs into supercapacitors shows good electrochemical energy storage properties.The maximum specific capacitance can reach 235.6 F/g,at 0.5 A/g current density.(2)These proposes a method for graft polymerization of spirodifluorene/aniline conjugated microporous polymers to prepare multi-arm carbon nanotube composites(MWCNT@SACMPs),aiming at the problem that the stability of the electrochemical energy storage cycle of SACMPs is not high.Based on the good electrical conductivity and physicochemical stability of MWCNTs,the effects of different MWCNT contents(5 wt%,8 wt%,10 wt%,15 wt%)on the specific surface area,specific capacitance and cycle stability of SACMP are discussed.Research shows that the specific surface area of 10 wt%MWCNT@SACMPs reaches 514 m²/g,and its energy storage properties are greatly improved compared to SACMP when assembled into a super capacitor.At a current density of 0.5 A/g,the specific capacitance can reach 334 F/g After 6000 cycles,the capacitance retention rate increased by about 40%.(3)To solve the leakage problem of phase change materials during heat storage.The proposed that a series of porous carbon spheres(HCSPs)with different pore sizes and wall thicknesses are prepared by using Si O₂ as a template and SACMPs as a carbon source by optimizing the template size,template content,polymerization conditions,and carbonization process.HCSPs have a rich pore structure that is good for supporting phase change materials,and good thermal conductivity is good for heat energy transport.After loading typical phase change material stearyl alcohol(ODA),it is found that HCSPs can support up to 80 wt%ODA.Through differential calorimetric scanning analysis,it is found that the latent heat of the composite phase change materials(ODA@HCSPs)as high as184.4 J/g,and it also has excellent package stability.It still maintains 91%of its latent heat storage performance after 50 heating cycles.