| Nitride radical polymer materials have the processability of traditional polymers and the reversible redox properties of stable organic radicals,so they are widely used in energy storage,catalysis,and biology.With a high redox potential and fast redox kinetic process,Nitroxide Radical Structure is an ideal cathode material sought after in varied systems such as lithium-ion batteries,sodium-ion batteries,zinc-ion batteries,and redox flow batteries.However,the existing problems of free radical polymer cathode materials hinder further development and large-scale application.Firstly,the low conductivity of the free radical polymer itself requires the introduction of conductive carbon materials in the electrode material,and the poor compatibility between the polymer and the conductive carbon leads to a low proportion of the polymer in the composite electrode,which reduces the specific energy of the electrode.Therefore,it is vital to improve the dispersion of the polymer on the carbon material surface through structural design.secondly,the disproportionation reaction of free radical structures under acidic conditions limits the application of nitrogen-oxygen radical polymer materials in Lewis acid electrolytes,such as Al-ion electrolyte systems.Therefore,exploring the disproportionation reaction mechanism and inhibiting side reactions to broaden the radical polymer positive electrode’s application has significant implications.This study addresses the above two critical issues,firstly optimizing the nitrogen oxide radical/carbon nanotube composite electrode by polymer structural design and constructing a fully organic battery,promoting the development of energy storage systems based on renewable materials.Secondly,by optimizing the Al-ion electrolyte system,we explore the reaction mechanism and inhibit side reactions,achieving the first water-based aluminum ion battery(AAIBs)based on nitroxide radical polymer positive electrode.The specific research content is as follows:(1)Addressing the scientific issue of poor dispersion of polymers in conductive carbons,we chemically modified PTMA with anthraquinone(AQ)to obtain P(TMA-coAQ).The AQ group and CNTs can promote dispersion of polymers in conductive carbon through non-covalent π-π interactions,improving the electrode electron transfer rate,optimizing the electrode performance of the composite electrode nitrogen oxide radical polymer/carbon nanotube,and improving the capacity and cycling stability of the polymer battery.Then,using P(TMA-co-AQ)as the positive electrode material and silver terephthalate(Ag2TP)whose potential is lower and power density matches PTMA as the negative electrode,a high-output fully organic battery was constructed.The results show that the P(TMA-co-AQ)/Ag2TP full battery system has a specific capacity of 182mAh g1 at 0.5C and an output voltage of up to 2.8V.(2)Through the exploration and research on the chemical and electrochemical behavior of 2,2,6,6-tetramethylpiperidinyl-1-oxyl radical(TEMPO)in aluminum trifluoromethanesulfonate(Al(OTF)3)organic solution and aqueous solution,we revealed that there is a reversible disproportionation of TEMPO in Al(OTF)3 aqueous solution to generate TEMPO anions and Al(OTF)3 complexes,and there is a fast ligand exchange between TEMPO complexes and H2O molecules.By exploring the reaction mechanism,we realized the reversible electrochemical redox of TEMPO in aqueous electrolytes and constructed the first aqueous aluminum-ion batteries(AAIBs)based on oxynitride radical polymer(PTMA)cathodes.The conclusion shows that the PTMA aqueous aluminum ion battery is flame retardant and air stable,can provide a stable output voltage greater than 1.0 V and a capacity of 110 mAh g-1,and a cycle stability of over 800 times. |
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