The ever-increasing consumption of a huge quantity of lithium batteries, for example, Li–MnO₂ cells, raises critical concern about their recycling. We demonstrate herein that decayed Li–MnO₂ cells can be further utilized as rechargeable lithium–air cells with admitted oxygen. We further investigated the effects of lithiated manganese dioxide on the electrocatalytic properties of oxygen-reduction and oxygen-evolution reactions (ORR/OER). The catalytic activity was found to be correlated with the composition of Li_xMnO₂ electrodes (0<x<1) generated in situ in aprotic Li–MnO₂ cells owing to tuning of the Mn valence and electronic structure. In particular, modestly lithiated Li_0.50MnO₂ exhibited superior performance with enhanced round-trip efficiency (ca. 76 %), high cycling ability (190 cycles), and high discharge capacity (10 823 mA h g_carbon⁻¹). The results indicate that the use of depleted Li–MnO₂ batteries can be prolonged by their application as rechargeable lithium–air batteries.

The ever-increasing consumption of a huge quantity of lithium batteries, for example, Li–MnO₂ cells, raises critical concern about their recycling. We demonstrate herein that decayed Li–MnO₂ cells can be further utilized as rechargeable lithium–air cells with admitted oxygen. We further investigated the effects of lithiated manganese dioxide on the electrocatalytic properties of oxygen-reduction and oxygen-evolution reactions (ORR/OER). The catalytic activity was found to be correlated with the composition of Li_xMnO₂ electrodes (0<x<1) generated in situ in aprotic Li–MnO₂ cells owing to tuning of the Mn valence and electronic structure. In particular, modestly lithiated Li_0.50MnO₂ exhibited superior performance with enhanced round-trip efficiency (ca. 76 %), high cycling ability (190 cycles), and high discharge capacity (10 823 mA h g_carbon⁻¹). The results indicate that the use of depleted Li–MnO₂ batteries can be prolonged by their application as rechargeable lithium–air batteries.

Flexible three-dimensional (3D) nanoarchitectures have received tremendous interest recently because of their potential applications in wearable electronics, roll-up displays, and other devices. The design and fabrication of a flexible and robust electrode based on cobalt sulfide/reduced graphene oxide/carbon nanotube (CoS₂/RGO-CNT) nanocomposites are reported. An efficient hydrothermal process combined with vacuum filtration was used to synthesize such composite architecture, which was then embedded in a porous CNT network. This conductive and robust film is evaluated as electrocatalyst for the hydrogen evolution reaction. The synergistic effect of CoS₂, graphene, and CNTs leads to unique CoS₂/RGO-CNT nanoarchitectures, the HER activity of which is among the highest for non-noble metal electrocatalysts, showing 10 mA cm⁻² current density at about 142 mV overpotentials and a high electrochemical stability.

Flexible three-dimensional (3D) nanoarchitectures have received tremendous interest recently because of their potential applications in wearable electronics, roll-up displays, and other devices. The design and fabrication of a flexible and robust electrode based on cobalt sulfide/reduced graphene oxide/carbon nanotube (CoS₂/RGO-CNT) nanocomposites are reported. An efficient hydrothermal process combined with vacuum filtration was used to synthesize such composite architecture, which was then embedded in a porous CNT network. This conductive and robust film is evaluated as electrocatalyst for the hydrogen evolution reaction. The synergistic effect of CoS₂, graphene, and CNTs leads to unique CoS₂/RGO-CNT nanoarchitectures, the HER activity of which is among the highest for non-noble metal electrocatalysts, showing 10 mA cm⁻² current density at about 142 mV overpotentials and a high electrochemical stability.