Unzipped carbon nanotubes for aluminum battery

Abstract

As low-cost commercial materials, the application of carbon nanotubes (CNTs) in the aluminum battery is limited by the lack of active intercalation sites. Herein, a flexible unzipped multi-walled carbon nanotubes (UCNTs) film consisting of graphene nanoribbons and a carbon nanotube backbone is prepared via a simple, low-cost and scalable method for high-performance aluminum battery positive electrode. In the nanostructure, the neonatal graphene nanoribbons provide numerous active intercalation sites to store AlCl4− anions, while the internal core CNTs are responsible for the rapid transportation of electrons to the active sites. Fast transportation of electrons and anions in UCNT film are simultaneously achieved, promoting the kinetics in the aluminum battery. Thus the UCNT-Al battery exhibits a high storage performance with a capacity as high as 100 mA h g−1 (current density: 2000 mA g−1) and a long cycle life of 5600 cycles with a capacity of 75 mA h g−1 (Coulombic efficiency: 98%) at 5000 mA g−1. Furthermore, the excellent flexibility and fast charging and variable discharging performance are beneficial for the development of portable devices. This work effectively tackles bottleneck caused by the lack of active sites for CNT-based aluminum batteries and accelerates the development of aluminum batteries.