A rechargeable lithium-oxygen (Li-O2) battery is considered as a promising technology for electrochemical energy storage systems because its theoretical energy density is much higher than those of state-of-the-art Li-ion batteries. The cathode (positive electrode) for Li-O2 batteries is made of carbon and polymeric binders; however, these constituents undergo parasitic decomposition reactions during battery operation, which in turn causes considerable performance degradation. Therefore, the rational design of the cathode is necessary for building robust and high-performance Li-O2 batteries. Here, a binder-free carbon nanotube (CNT) electrode surface-modified by atomic layer deposition (ALD) of dual acting RuO2 as an inhibitor-promoter is proposed for rechargeable Li-O2 batteries. RuO2 nanoparticles formed directly on the binder-free CNT electrode by ALD play a dual role to inhibit carbon decomposition and to promote Li2O2 decomposition. The binder-free RuO2/CNT cathode with the unique architecture shows outstanding electrochemical performance as characterized by small voltage gaps (∼0.9 V) as well as excellent cyclability without any signs of capacity decay over 80 cycles.
Bibliographical noteFunding Information:
This work was supported by Basic Science Research Program (No. NRF-2016R1D1A1 B01015557) and the Basic Research Laboratory Program (No. NRF 2015-041523) through the National Research Foundation of Korea funded by the Ministry of Education, Science and Technology. This work was also supported by Samsung Research Funding Center of Samsung Electronics (No. SRFC-TA1603-02).
All Science Journal Classification (ASJC) codes
- Materials Science(all)