Vertically aligned carbon nanotube-ruthenium dioxide core-shell cathode for non-aqueous lithium-oxygen batteries

摘要

Exploitation of hierarchical porous carbons is increasingly attractive for high-capacity lithium (Li)-oxygen (O-2) battery cathodes. However, their practical applications in non-aqueous electrolytes are limited by poor rechargeability, primarily due to the decomposition of carbon electrode and electrolyte. In this work, we report a vertically aligned carbon nanotube (VACNT)-ruthenium dioxide (RuO2) core-shell (VACNT@RuO2) cathode for non-aqueous Li-O-2 batteries. The cathode is fabricated with VACNT as the core material and hydrous RuO2 as the shell material, which eliminates the direct contact between the carbon and nucleophilic reactive intermediate species in the electrolyte. In comparison with the VACNT cathode, the VACNT@RuO2 cathode presents a superior rate capability (3.3-fold less reduction in capacity) and cycling stability (sustainable for 100 cycles), with a maximum capacity as large as 13.2 mAh cm(-2) (6600 mAh g(electrode)(-1)) at 1.0 mA cm(-2). The proposed cathode exhibiting a binder-free and hierarchical core-shell structure is a promising candidate for rechargeable non-aqueous Li-O-2 batteries. (C) 2016 Elsevier B.V. All rights reserved.