Identification of reversible insertion-type lithium storage reaction of manganese oxide with long cycle lifespan

In this study, δ-MnO2 of thickness 8 nm anchored on the surface of carbon nanotubes (CNT) by Mn-O-C chemical bonding is synthesized via a facile hydrothermal method. Numerous ex-situ characterizations of the lithium storage process were performed. Furthermore, density functional theory (DFT) calculations indicated that δ-MnO2 (0 1 2) thermodynamically prefers bonding with CNTs. Moreover, the interfacial interaction reinforces the connection of Mn-O and reduces the bond strength of Li-O in lithiated MnO2, which could facilitate an intercalation-type lithium storage reaction. Consequently, the as-synthesized δ-MnO2 retains an excellent reversible capacity of 577.5 mAh g−1 in 1000 cycles at a high rate of 2 A g−1 between 0.1 V and 3.0 V. The results of this study demonstrate the possibility of employing the cost-effective transition metal oxides as intercalation lithium storage dominant electrodes for advanced rechargeable batteries.Graphical abstractCycle performance with different cut offs under the rate 2 A g–1. Inset: schematic of circulation between 0.1–3.0 V.
Source: Journal of Energy Chemistry - Category: Chemistry Source Type: research