Improved Performance of Zinc Composite//Secondary Doped Li-PANI Composite Film for Rechargeable Batteries

Abstract

To improve the conductivity of pure polyaniline (PANI), compact scale-like PANI secondary doped with lithium chloride (Li-PANI) was prepared after the in-situ synthesis of PANI powder using the constant current method and 4,4’-diaminobiphenyl (DABP) as an additive in hydrochloric acid (HCl) solution. The compact morphology of obtained Li-PANI was feasible for improvement the charge transfer in the PANI chains and inter-molecular. The oxidation peak currents of Li-PANI with DABP additive were nearly three times higher than those of the Li-PANI and much higher than those of in-situ doped PANI in only HCl solution. Both the LiCl-PANI/TiO2/C/DABP composite ( Li-PANI composite) and Zn/ZnO/MgO/CMC-Na composite (Zn composite) were prepared by homogeneously coating at controlled thicknesses (0.20 mm and 0.04 mm, respectively). A Zn composite was used as cathode and Li-PANI composite as anode for the fabrication of improved Zn//PANI battery, with an open voltage of approximately 1.5 V in ZnCl2+LiCl electrolyte solution. The battery charge/discharge cycle performance was determined between 0.7 V and 1.7 V. The discharge capacity of the cathode reached 131.4 mAh·g-1 at a current density of 2 mA·cm-2. During 35 charge/discharge cycles, the average decrease in the discharge capacity of each cycle was 0.07%, indicating that the cycle performance and stability of the designed battery revealed the feasible competition potential with traditional batteries.