Electrochemical properties of electrospun polyindole nanofibers as a polymer electrode for lithium ion secondary battery

Polyindole nanofiber is prepared using electrospinning technique for the first time and evaluated as cathode active material for application in lithium ion battery. Surface morphology of the cathode is studied using scanning electron microscope. It shows porous structure constructed by nanofibers with diameter ranged from 347 nm to 180 nm. Electrochemical evaluation of the Li/polyindole nanofiber battery shows good cycling properties as well as fast charge and discharge properties. The battery achieves about 3.0 V electromotive force with discharge capacity of 83 mAh g−1 which is about 99% of theoretical value. There is slow capacity fading during cycling and the discharge capacity drops to 72% of theoretical capacity after 500 cycles at discharge current density of 40 mA g−1. At higher discharge current density like 200 mA g−1 and 400 mA g−1, the cell still can deliver stable discharge capacity of 79 mAh g−1 and 70 mAh g−1. Temperature performances test of the Li/polyindole nanofiber battery shows that the discharge capacity of the Li/polyindole nanofiber battery increases with temperature increasing. In summary, the test results have proved that polyindole nanofiber is a good candidate as cathode material for lithium ion battery.

► Polyindole nanofiber is fabricated by electrospinning using acetonitrile as solvent.
► A lithium/polyindole nanofiber battery is constituted by using polyindole nanofiber.
► The lithium/polyindole nanofiber battery achieves 83–75 mAh g−1 discharge capacity.
► The battery has excellent cycle property and fast charge/discharge performance.