Chitosan was applied as the electrode binder material for a spherical graphite anode in lithium-ion batteries. Compared to using poly (vinylidene fluoride) (PVDF) binder, the graphite anode using chitosan exhibited enhanced electrochemical performances in terms of the first Columbic efficiency, rate capability and cycling behavior. With similar specific capacity, the first Columbic efficiency of the chitosan-based anode is 95.4% compared to 89.3% of the PVDF-based anode. After 200 charge–discharge cycles at 0.5 C , the capacity retention of the chitosan-based electrode showed to be significantly higher than that of the PVDF-based electrode. Electrochemical impedance spectroscopy (EIS) and scanning electron microscopy (SEM) measurements were carried out to investigate the formation and evolution of the solid electrolyte interphase (SEI) formed on the graphite electrodes. The results show that a thin, homogenous and stable SEI layer is formed on the graphite electrode surface with chitosan binder compared with that using the conventional PVDF binder
Wen Liu,Yueli Shi,Quanchao Zhuang,Yongli Cuiab,Zhicheng Ju,Yanhua Cui
The effect of ethylene glycol bis(propionitrile) ether(DENE) as a novel electrolyte additive on the electrochemical performance of a graphite anode was studied in this paper. Fourier transform infrared spectroscopy(FTIR), charge/discharge tests, cyclic voltammetry(CV), X-ray photoelectron spectroscopy(XPS), scanning electron microscopy(SEM), and electrochemical impedance spectroscopy(EIS) were used to investigate the SEI film and the cycle performance of graphite anode. The initial charge capacities of the graphite electrode in the electrolytes without and with 1% DENE were 319 mAhg −1 and 349 mAhg −1 , respectively. After 60 cycles, the charge capacities without and with 1% DENE were 315 mAhg -1 and 350 mAhg -1 , respectively. and the capacity retention rates were 95.8% and 98.1%, respectively. DENE promoted the formation of a thin and uniform SEI layer and improved the stability of the electrode. The addition of DENE effectively improved the electrochemical performance of graphite anodes.