| Organic radical polymers(ORPs)are one kind of polymer possessing radical groups on its side chain.Due to the advantages of extensive raw materials,safety,non-toxity,low cost and high energy density,ORPs are widely applied in many fields,such as energy storage,energy conversion,radical calibration,and so on.In this work,the series of radical epoxy polymers PBOB and PTEOCZ-n(where n is the percentage of carbazole group,n=0,5,10,30,50,70,100)were synthesized.The 3-(2,2,6,6-tetramethylpiperidine-1-oxy-4-oxy)propylene oxide(GTEMPO)was employed to crosslink with 1,4-bis(1,2-epoxypropoxy)phenyl ether(BOMB)and N-(1,2-epoxypropyl)-carbazole(GCZ),respectively.And PBOB was applied as cathode material in the secondary battery,the performance of the batter ies was systematically characterized compared with their counterpart PTEO-based cathode.The random copolymers PTEOCZ-n were synthesized by regularizing the GCZ ratio,and the properties of the polymers were characterized.The influence of GCZ ratio in the polymer and additive content on photovoltaic performance were investigated.The main contents are as follows:Firstly,TEMPO-based ORPs,such as PTMA,PTEO are usually used as positive active materials in lithium-ion batteries,exhibiting excellent rapid charge/discharge and high cycle stability.However,the TEMPO-based polymers are easily dissolved in electrolyte,which limits the battery performance.Thus,the PBOB was synthesized by utilizing BOMB and TEMPO with cross-linked structure as comonomers and it was found that the solvent resistance was improved.Then the positive electrodes were prepared by mixing with superconducting carbon black and applied in the secondary battery.Compared with PTEO cathode material,the PBOB exhibited better performance with a capacity of 78.0 m Ah/g which is much higher than the PTEO-based battery of 38.6 m Ah/g.The capacity of PBOB-based cathode still remains 84.4%of the initial capacity after 100 charge-discharge cycles,which is much higher than the PTEO cathode material of 64.8%.The electrochemical impedance(Rct)of PBOB-based cathode is about 72?,that is much smaller than PTEO-based cathode Rct=137?.This is certified the new cross-linking group could effectively improve the electrochemical properties of the PBOB.Secondly,GTEMPO and GCZ were selected to regulate the performance of ORP,and a series of random copolymers PTEOCZ-n(where n is the percentage of carbazole group)were obtained by adjusting the GCZ content.The radical behavior of random copolymers(PTEOCZ-n)were demonstrated by electron paramagnetic resonance(EPR)spectra.All the polymers showing good homogeneity for the dispersibility index(PDI)were located at1.38?1.09.The decomposed temperature(5%weight-loss temperature)of polymers were all greater than 235?,demonstrating the studied materials having enough thermal stability.Thirdly,a series of random copolymers PTEOCZ-n(in Chapter 3)are selected as additives for polymer solar cells(PSCs).The influence of the additive's ratio,and the content of GCZ in PTEOCZ-n for the morphology optimization,devices mobilities and devices performance were systematically investigated.These experimental results show that when wt.0.5%CN and wt.1%PTEOCZ-30 were added,the device exhibited the highest power conversion efficiency(PCE)up to16.67%with filling factor(FF)of 72.46%.Compared with wt.0.5%CN only devices,the optimized device performance was improved by 5.7%.The morphology analysis shows that the morphology control of PM6:Y6 system can be achieved by adjusting the content of GCZ in the random copolymer PTEOCZ-n.The device mobilities test shows that the electron and hole mobility based on the optimal device(PM6:Y6+1%PTEOCZ-30+0.5%CN)are?e=4.95×10-4 cm2 V-1 s-1 and?h=5.74×10-4 cm2 V-1 s-1,respectively.Which are both higher than the(PM6:Y6+0.5%CN)-based devices for?e=2.97×10-4 cm2 V-1 s-1 and?h=4.30×10-4 cm2 V-1 s-1,respectively.This work proves that the radical polymer additive PTEOCZ-30 can change the mobility of the device,promo te the increasement of current,and achieve higher photoelectric conversion efficiency. |
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