High-Loading CNT on Polymer Nanofiber as a Stand-Alone Anode Material for Li-Ion Battery
Journal
ACS Omega
Date
2019.02.25
Abstract
To address the instability and repulsive interaction of Carbon Nanotube (CNT) in Li-ion battery (LIB), mixed polymers (PAN and PVP) were employed as matrix support to ensure CNT particles remain in place during charge/discharge and prevent particle migration. Various CNT-based anode reports have been reported but these require metal support that could result to contact resistance, hence, free-standing CNT electrode is an attractive option. A simple method of electrospinning polymers and calcination at 800 ˚C is presented with CNT loading as high as 50 wt％ can be obtained without binder and acts as main active material rather than an additive like previous studies. The anode (PP-CNT) showed excellent performance with high discharge specific capacity of 960 mAh/g at current density of 200 mA/g. The capacity at higher current density (1600 mA/g) remained greater than graphite (372 mAh/g) at 521 mAh/g and showed high stability for 675 cycles without exhibiting any significant capacity loss with a coulombic efficiency of >95％. Rate capability experiment showed the reversibility of PP-CNT after subjecting to an increasing current density and regaining >95％ of the initial capacity at low current density (200 mA/g). The high capacitive performance of the material is attributed to the high loading of CNT and its containment within the bulk of the polymer matrix to prevent particle migration and agglomeration as well as the capacity of the nanofibers to preserve a tight proximity of the electrolyte-electrode interface.