Highly Oriented Carbon Nanotube Sheets for Rechargeable Lithium Oxygen Battery Electrodes.

Abstract

Lithium oxygen batteries are one of the next generation rechargeable batteries. High energy density of lithium oxygen batteries have been considered as a very attractive power option for electric vehicles and many other electronic devices. However, they still faced substantial challenges such as short cycle life, large voltage hysteresis, low gravimetric and volumetric power. Here we developed a highly aligned CNT structured sheet for favorable lithium oxygen cathode electrodes. We fabricated highly oriented CNT sheets by rolling vertically aligned CNT arrays. Highly oriented CNT sheets provide excellent electrical conductivity with favorable mesoporous structure for cathode electrode. As a result, the CNT sheet performed maximum discharging capacity of 1810 mA/gc. We found that electrical conductivity and pore distribution plays important rolls for improving performance in lithium oxygen batteries. This study suggests new strategies of designing highly efficient porous carbon electrodes for lithium oxygen batteries.