Long life rechargeable Li-O2 batteries enabled by enhanced charge transfer in nanocable-like Fe@N-doped carbon nanotube catalyst

Abstract

Rechargeable Li-O2 batteries have attracted considerable interests because of their exceptional energy density. However, the short lifetime still remained as one of the bottle-neck obstacles for the practical application of rechargeable Li-O2 batteries. The development of efficient cathode catalyst is highly desirable to reduce the energy barrier of Li-O2 reaction and electrode failure. In this work, we report a facile strategy for the fabrication of a high-performance cathode catalyst for rechargeable Li-O2 batteries by the encapsulation of high content of active Fe nanorods into N-doped carbon nanotubes with high stability (denoted as Fe@NCNTs). First-principles calculations reveal that the synergistic charge transfer and redistribution between the interface of Fe nanorods, the CNT walls and the active N dopants greatly facilitate the chemisorption and subsequent dissociation of O2 molecules into the epoxy intermediates on the carbon surface, which benefits the uniform growth of nanosized discharge products on CNT surface and thus boosts the reversibility of Li-O2 reactions. As a result, the cathode with Fe@NCNT catalyst exhibits long cycling stability with high capacities (1000 mA h g −1 for 160 cycles and 600 mA h g −1 for 270 cycles). Based on the total mass of Fe@NCNTs + Li2O2, high gravimetric energy densities of 2120-2600 W h kg −1 can be achieved at the power densities of 50-795 W kg −1 .

Recent advances in flexible supercapacitors based on carbon nanotubes and graphene

“…More importantly, carbon materials are suitable for constructing flexible supercapacitors due to their large surface area, high electrical conductivity, as well as good chemical and mechanical stability [28][29][30][31][32][33][34][35]. Several excellent reviews summarized the development of flexible electrodes for energy storage devices [29,31,36].…”

Recent advances in hybrid sodium–air batteries

“…Metal-based catalysts are rising for energy conversion and energy storage devices owing to their superior OER performance and satisfactory cycle performance [135].…”

Performance and Sustainability Tradeoffs of Oxidized Carbon Nanotubes as a Cathodic Material in Lithium‐Oxygen Batteries

“…Carbon‐based LOB cathodes have been constructed using carbon nanofibers, [8,9] carbon black, [10,11] graphene, [12–14] and carbon nanotubes [10,15,16] . Of these materials, multi‐walled carbon nanotubes (MWCNTs) are particularly promising and have attracted significant interest as a result; [17–19] however, previous studies have reported widely variable specific discharge capacities at the same experimental conditions for MWCNT cathodes (Figure 1), [15,16,20–26] while there are very few systematic studies to explicitly evaluate the cycling life of MWCNT cathodes as it relates to their material properties. While some of this variation may stem from differences in cathode preparation methods, binders, and electrolytes, efforts to identify the MWCNT material properties that impact performance are complicated by a lack of robust characterization.…”

“… Specific discharge capacity of “pristine” (black) and “oxygen‐functionalized” (blue) MWCNT cathodes used in LOBs from 2011–2020 with a current density of 100 mA g −1 carbon and a final discharge potential of 2.0–2.4 V [15,16, 20–26] …”