Effects of post-treated carbon nanotube films on electrochemical performance for bendable lithium-ion batteries

Abstract

The different post treatments of carbon nanotube (CNT) films were studied to investigate the effects of their crystalline perfection on lithium-ion battery performance. The crystal structures of the CNT films were differently developed by heat and acid-heat treatments. The treated CNT films were prepared as an anode electrode for use in flexible lithium ion batteries. This free-standing electrode did not contain a polymeric binder, conducting carbon powder and current collector. The electrochemical performance of the electrodes made with differently treated CNT films was evaluated via charge-discharge test, cyclic voltammetry and impedance measurement. The heat treated CNT films showed a higher capacity (250 mAh/g at a 0.5C rate) due to the increase of their crystalline perfection compared to the raw CNT films. In addition, the CNT film electrodes exhibited a good capacity retention at a high charging rate. This result suggested that the CNT film electrodes performed well without some components within cells. Eventually, the CNT films might be utilized for bendable lithium-ion batteries due to their flexibility and high electrical conductivity. The CNT films would be a potential electrode material for a specific thin/bendable lithium-ion battery that does not need a high capacity.