Construction And Performance Of Carbonyl Compounds-based Aqueous Energy Storage Devices

Organic materials have the advantages of high specific capacity,adjustable structure,and high sustainability.When organic materials are applied to aqueous energy storage systems,they exhibit great application prospects in constructing energy storage devices with high energy density,high power density,low cost and high security.Among the organic electrode materials,carbonyls have received much attention and developed rapidly in recent years for their high electrochemical reversibility,fast reaction kinetics and excellent rate performance.However,the poor conductivity,low redox plateau and high solubility of carbonyls have greatly limited their research and application.We effectively ameliorates the above problems by polymerization and compounding them with conductive substrates.We further investigated the energy storage performance of optimized composites in water-based supercapacitors and zinc ion batteries,and the electrochemical performance of the electrodes was significantly improved.The main work of this thesis includes the follows:1.A strategy of constructing thick and dense organic composite electrodes with high areal specific capacitance and high volumetric specific capacitance was proposed.And a universal preparation method of high-density organic molecule/graphene composite with high electron conduction and ion transport was also developed.Through the"face-to-face"non-covalent interaction,the AQS was effectively compounded to the graphene.The electron transmission paths between AQS and graphene are shortened and the conductivity of the composite is highly improved.By capillary drying,the composite is densified.In the meantime,the connecting three-dimensional network is effectively maintained.Combined with the auxiliary transmission to the proton of sulfonate on the AQS,the ion conductivity is significantly improved.Finally,a thick（200μm）and dense(1.38 g cm^-3)organic composite electrode with high areal specific capacitance(13.3 F cm^-2)and high volumetric specific capacitance(650 F cm^-3)was obtained.2.We investigated the electrochemical performance of quinone molecules/graphene in zinc ion energy storage systems,and a cathode material with high volumetric electrochemical performance was constructed.We further use benzoquinone as the basic structural unit to construct poly（2,5-dihydroxyaniline）/carbon cloth（PDHA/CC）electrode by in-situ electro-polymerization.The PDHA/CC electrode combines the high specific capacity of quinones and the high conductivity of polyaniline.The synergetic effect of the two together guarantees a high specific capacity.It is applied in zinc ion battery,a maximum specific capacity of 152m Ah g^-1 and a high discharge plateau 1.25 V vs Zn/Zn²⁺was achieved.Based on this,the influence of polymerization degree on the electrochemical performance of PDHA/CC electrodes was also studied.As the degree of polymerization increased,the specific capacity tends to increase first and then decrease.The electrochemical performance behaves best when it’s polymerized for 20 cycles through the cyclic voltammetry profiles.In summary,three-dimensional assembly and hierarchical construction of organic materials have been achieved through molecular structural design and macro-compositing with carbon materials.The reaction mechanism and electrochemical behavior were also investigated,which is significant for the practical application of carbonyl compounds.