DOI: 10.5176/2301-3516_OPAP13.07
Authors: P. B. Anand, Rajive. M. Tomy, K. M. Anilkumar and S. Jayalekshmia
Abstract:
The present work is aimed at investigating the structural and electrochemical properties of Li-ion cells, assembled using Li-substituted polyaniline (PANI) as the cathode active material. Polyaniline is a remarkably potential soft material with interesting structural and electrical properties and excellent stability and is hence opted as the host material for cathode preparation. In the present work, emeraldine salt form of PANI was synthesized via oxidative polymerization method. It was de-doped to get emeraldine base form of PANI and then treated with “n-Butyllithium in hexane (n-BuLi)” to get the Li-substituted form of PANI, since n-BuLi partially disaggregates the polyaniline clusters by binding the amines to its lithium centers. It is used as a strong base and this process is referred to as metalation. The lithiation was carried out in an argon (99.999{6e6090cdd558c53a8bc18225ef4499fead9160abd3419ad4f137e902b483c465} purity) filled glove box. Concentration of the n-BuLi was varied and the level of lithiation was analyzed using atomic emission spectroscopy. X-ray diffraction, FTIR and SEM techniques were used to get the structural and surface morphological details of the Li-substituted PANI (LIPO) sample. Coin cells were assembled in the glove box using LIPO as cathode and lithium metal foil as anode with 1 M LiPF6 in EC: DMC (1:1) as electrolyte. Voltage sweep cyclic voltammetry and charge-discharge cycling were employed to characterize the electrochemical capabilities. The cells are found to show a maximum discharge capacity of 22 mAh/g with 99.99 {6e6090cdd558c53a8bc18225ef4499fead9160abd3419ad4f137e902b483c465} columbic efficiency and have got tremendous cycling stability over 50 cycles. It is observed that these cells can sustain the cycling stability up to 1000+ cycles. There are no reports on the electrochemical characteristics of Li-ion cells using n-BuLi treated PANI as cathode material. n-Butyllithium is a cheaper dopant compared to other expensive dopants like LiPF6, LiBF4 etc. By suitably optimizing the Li- doping conditions, it is expected that the specific capacity of these cells can be considerably enhanced.
Keywords: Polymer based Li-ion battery, Lithiated PANI, Conducting Polymers
Updating...