The Preparation Of Benquinone-based Electrode Materials And Research On Its Application Performance In Rechargeable Lithium Organic Batteries

The small quinone materials are regarded as the most important electrode materials in the carbonyl electrode matertials for secondary batteries owing to their higher redox potentials and higher theoretical capacities.It is possible to meet the future energy requirement for advanced lithium and sodium ion batteries though the organic structure adjust and electrochemical improvement.However,many challenges remain for the practical application of quinone materials,such as their tendency to dissolve,low conductivity and low discharge voltage.Some number of effective strategies have been developed to suppress the dissolution of organic electrode materials such as the use of anchoring,polymerization,nanostructures,and solid-state electrolytes.The relatively low potential of the organic cathode electrodes can be improved by adding electron withdrawing groups and the longer conjugated structure.Therefore,in order to obtain excellent cycling performance,it is of great importance to develop li-organic batteries with structure adjustment and other strategies.Our works about benzoquinone organic materials as follows:1.Poly?2-chloro-3,5,6-trisulfide-1,4-benzoquinone??PCTB?was prepared by polymerization of chloranil through thioether bonds,and found to be suitable as active material for LIBs.FTIR and EDX confirm the existence of-Cl and C-S in the product,indicating the successful formation of the C-S-C during the polymerization process.By adding electron withdrawing groups,the potential at which the organic cathode accepts an electron is increased.The CV curve shows that a pair of radox peaks at 3.13/2.68 V.Therefore,PCTB exhibits a superior lithium-storage performance with high discharge potential.Without any modification,PCTB showed a discharge capacity of 103 mA h g^-1 at 65 mA g^-1 with an average voltage of 2.72 V vs.Li⁺/Li.The specific capacity of PCTB is lower than except may be caused by the slow lithiation/delithiation kinetics of large particles.Optimization of PCTB morphological is needed to get a better lithium storage performance.The results shed light on the application of organic carbonyl compounds as electrode materials for LIBs.2.The quinone electrode materials are recognized as the mostly applied materials in the organic materials for rechargeable batteries because of the potential to achieve high energy density and highly power density.An attractive organic electrode material,dicarboxylates-quinone-based copolymer,has been synthesized and assessed as a cathode for rechargeable lithium batteries.It was prepared by copolymerization of Tetrachlorophthalic anhydride?TCPA?and 2,3,5,6-Tetrachloro-1,4-benzoquinone?TCBQ?.The Fourier transform infrared spectroscopy,Elemental analysis,and X-ray photoelectron spectroscopy analysis were performed to get understanding of the polymer structure(C₁₄O₆S₄Na₂).All the carbonyl groups from different active units will contribute to the capacity and increase the utilization of the active sites.Moreover,this polymer can have the properties of the high stability of the dicarboxylates unit and the high capacity of the quinone unit.A positive-electrode which incorporated the active material showed a high discharge capacity of 183 mA h g^-1 at 30 mA g^-1 in the voltage range of 1.5-4.0 V.After 100 cycles,67%of the maximum capacity was retained.The highest reduction potential is 3.61 V.3.Despite the fascinating Li storage properties of organic carbonyl compounds,e.g.,high theoretical capacity and fast kinetics,there still exist critical cyclability problems owing to dissolution of active materials into the liquid electrolyte.Unlike other strategies,the use of all-solid-state electrolytes to produce solvent-free Li-organic batteries inherently prevents the dissolution of organic electrode materials.Herein,a generic strategy is proposed by combining quinone-based polymer cathode and composite polymer electrolyte?CPE?for excellent cycling stability and high discharge voltage for lithium organic batteries.The all-solid-state Lithium organic batteries have been designed by using PCTB and PA-BQ cathodes and poly?ethylene glycol??PEO?based CPE.The CPE of PEO-LiClO₄-10 wt%Li_0.3La_0.566TiO₃?LLTO?has an optimum ionic conductivity of 7.99×10^-4 S cm^-1 at 70?.Furthermore,the all-solid-state cells with a cathode containing 50 wt%PCTB exhibit a maximum discharge capacity of104.1 mA h g^-1 with an average potential of 2.72 V at 70?.After 300 cycles,90%and77%of the maximum capacity can be retained for PCTB and PA-BQ.4.Unlike other strategies,the use of all-solid-state electrolytes to produce solvent-free Li-organic batteries inherently prevents the dissolution of organic electrode materials.At the same time,a in-situ polymerization strategy to fabricate the composites of polymer and carbon black can effectively allow the sufficient contact of polymer and carbon black.The all-solid-state Lithium organic batteries have been designed by using composites cathodes and poly?ethylene glycol??PEO?based CPE.The CPE of PEO-LiClO₄-10 wt%TiO₂ has an optimum ionic conductivity of 1.74×10^-3 S cm^-1 at 70?.Furthermore,the all-solid-state cells have a high discharge capacity and stable cycle performance.After 300 cycles,92%and 79%of the maximum capacity can be retained for PCTB and PA-BQ.The in-situ of the organic carbon composite cathode material has a higher loading of the organic electrode material and a lower R_ct.The assembled solid-state lithium ion battery has a discharge specific capacity of at least 13%higher than that of the composite obtained by physical mixing under the same test conditions.