| Traditional lithium-ion batteries with the organic electrolyte has some shortcomings, such as high price, strict operating conditions and poor safety performance. However, aqueous rechargeable lithium-ion batteries which use inorganic lithium salt solution as electrolyte are more environmentally safe, low cost and easy preparation. More importantly, compared with the organic electrolyte, ionic conductivity of aqueous electrolyte solutions is much higher. Therefore, ARLBS(aqueous rechargeable lithium-ion batteries) has naturally become the best candidate for the new green chemical energy.However, a narrow window of electrochemical solution makes available a limited cathode or anode material.Anode materials unstable structure in aqueous solution lead to low discharge specific capacity and poor cycling stability. The exhibition of ARLBS electrochemical properties are largely affected by those factors.Different from the traditional inorganic materials, the organic polymer materials theoretical specific capacity is higher. Their structure can be designed and the synthesis route is environmental. This materials also have the advantage of recycling, they are expected to become the development direction of new storage materials. The small molecular quinone compounds based on conjugated carbonyl can exhibit good reversibility of electrochemistry. In addition, by means of polymerization we can improve their stability and get better electrochemical performance.The research on organic quinone polymer as the cathode materials is increasing, but as the anode electrode material in ARLBS are rarely reported. This article synthesis two kinds of organic quinone polymer compounds (PBQS and PDBM). As ARLBS anode, their electrochemical properties and associated structure was sudied. FTIR, NMR, EA were used to explore the polymerization process of PBQS and PDBM. Using SEM to observe particle size of PDBM, surface morphology and uniformity of distribution The difference of electrochemical properties in PBQS and PDBM were tested by cyclic voltammograms (CV), galvanostatic charge/discharge and impedance spectroscopy (EIS).(1) By using the trachloro-p-benzoquinon monomer(TCQ), the poly(benzoquinonylsulfide) (PBQS) material was synthesized by a simple polycondensation reaction. The results show that the electrochemical performance of PBQS is mainly dependent on the mole ratio of S and Na2S. two Chlorine atoms are replaced, the PBQS with a stable structure was obtained, When the mole ratio of S and Na2S is 0.4:1. It has the biggest discharge capacity, satisfactory rate capability and excellent cyclability. PBQS-0.4 deliver an initial specific capacity of 142.3 mAh/g,120.4 mAh/g at the current rates of 100 mA/g 1000 mA/g. When the current gets back to 100 mA/g, the capacity can recovers to 140.0 mAh/g. The initial discharge capacity of PBQS-0.4 at 200 mA/g is 138.4 mAh/g, through 200 cycles, the coulomb efficiency is always maintained at above 95%and capacity retention rate is 86.6%.(2) By using the 2,5-Dihydroxy-p-benzoquinone monomer, the PDBM material was successfully synthesized by an easy acetal reaction. By investigating the electrochemical performance of PDBM prepared by different reaction temperature and milling time. It indicated that PDBM which reacted at 30?and milled 5 hours has the highest discharge specific capacity and better cyclability. The initial discharge capacity at 100 mA/g is 85.0 mAh/g, 87.6% of the capacity is maintained after 50 cycles. EIS results show that the resistance of PDBM milled by 5 hours is the lowest. Since the sample particle size decreases, it not only reduce the diffusion resistance and improve the electrode reaction activity, but also favorable to the electrochemical performance. However, in a continuous cycle, the impedance is slightly increased, this may be due to an organic polymeric material itself is unstable and sparingly soluble, the polarization of the electrodes actually increase, it will lead to the capacity fading of PDBM. |
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