Carbon Nanotube@RuO2 as a High Performance Catalyst for Li–CO2 Batteries

Efficient electrocatalysts for Li₂CO₃ decomposition play an important role in Li-CO₂ batteries. In this paper, carbon nanotubes (CNTs) decorated with RuO₂ is firstly introduced as cathode materials for Li-CO₂ batteries. The CNT@RuO₂ composite can not only deliver a high specific capacity but also a lower charge voltage. With the CNT@RuO₂ cathodes, the Coulombic efficiency still remains around 100% until the 15th cycle. The charge voltage of early 30 cycles at a current of 50 mA·g^-1 with a capacity limit of 500 mAh·g^-1 can be fully lowered under 4.0 V. Particularly, the CNT@RuO₂ cathode can realize most decomposition of prefilled Li₂CO₃ and show a platform at around 3.9 V. This catalytic activity toward both in situ formed and preloaded Li₂CO₃ is more feasible for practical application in complex environment.