Vertically aligned ZnO nanorod core-polypyrrole conducting polymer sheath and nanotube arrays for electrochemical supercapacitor energy storage

Nanocomposite electrodes having three-dimensional (3-D) nanoscale architecture comprising of vertically aligned ZnO nanorod array core-polypyrrole (PPy) conducting polymer sheath and the vertical PPy nanotube arrays have been investigated for supercapacitor energy storage. The electrodes in the ZnO nanorod core-PPy sheath structure are formed by preferential nucleation and deposition of PPy layer over hydrothermally synthesized vertical ZnO nanorod array by controlled pulsed current electropolymerization of pyrrole monomer under surfactant action. The vertical PPy nanotube arrays of different tube diameter are created by selective etching of the ZnO nanorod core in ammonia solution for different periods. Cyclic voltammetry studies show high areal-specific capacitance approximately 240 mF.cm(-2) for open pore and approximately 180 mF.cm(-2) for narrow 30-to-36-nm diameter PPy nanotube arrays attributed to intensive faradic processes arising from enhanced access of electrolyte ions through nanotube interior and exterior. Impedance spectroscopy studies show that capacitive response extends over larger frequency domain in electrodes with PPy nanotube structure. Simulation of Nyquist plots by electrical equivalent circuit modeling establishes that 3-D nanostructure is better represented by constant phase element which accounts for the inhomogeneous electrochemical redox processes. Charge-discharge studies at different current densities establish that kinetics of the redox process in PPy nanotube electrode is due to the limitation on electron transport rather than the diffusive process of electrolyte ions. The PPy nanotube electrodes show deep discharge capability with high coulomb efficiency and long-term charge-discharge cyclic studies show nondegrading performance of the specific areal capacitance tested for 5,000 cycles

Evaluation of acoustic emission as a suitable tool for aging characterization of LiAl/LiMnO2 cell

International audienc

Study of Solid Electrolyte Interface Formation and Lithium Intercalation in Li-Ion Batteries by Acoustic Emission

International audienc

Experimental analysis of short-circuit scenarios applied to silicon-graphite/nickel-rich lithium-ion batteries

International audienceShort-circuit incidents pose a severe safety threat to lithium-ion batteries duringlifetime. Understanding the underlying electrochemical behavior can help to mitigatesafety risks. The electrochemically-caused rate-limiting behavior is analyzed using aquasi-isothermal test-bench, where external and local short-circuit conditions are appliedto single-layered pouch cells ( 3.2 V vs. Li/Li$^+$), which could be estimated up to 20%of the negative current collector mass

Thin film polyaniline-polyaniline electrochemical cells

10.1007/BF00266125Journal of Applied Electrochemistry23101031-1038JAEL