Initial Capacity Fading of Meso-phase Pitch Based Carbon Fiber as Anode Material of Lithium Ion Battery

摘要

The origin of initial capacity fading of MPCF3000, an artificial graphite fiber, as anode material for lithium ion batteries was studied with organic electrolytic solution 1M LiPF6 in ethylene carbonate (EC) and diethyl carbonate (DEC) (1 : 1). There was a reversible potential plateau at the region of 30 ~ 60 mVLi/Li + . This potential plateau disappeared during cycling, leading to fast capacity fading and low Ah efficiency. This potential plateau was not influenced by the charging to 50 mVLi/Li + . When the electrode was charged by constant current step pulse (20 charges to 22.7 mA/g-carbon with each charge followed by 30 minutesof rest, and another 20 charges to 3.78 mA/g-carbon with each charge followed by 30 minutes of rest) to the potential of 5 mVLi/Li + , the plateau was found at the first cycle only.