In situ growth of mixed-valence 2D α-MnOx nanosheets within interlayer spaces of multilayer Ti3C2 MXene as an efficient air cathode for rechargeable Li–O2 batteries

Abstract

Rechargeable Li–O₂ batteries are promising options for energy storage systems due to their simple fabrication, non-toxicity, and low cost. Herein, we present a new cathode design for Li–O₂ batteries, featuring non-stoichiometric, mixed-valence 2D α-MnO_x nanosheets (Mn⁴⁺/Mn³⁺/Mn²⁺) confined within multilayered MXene (M–Ti₃C₂). Electrochemical results show that the 2D α-MnO_x@M–Ti₃C₂ electrode achieved a specific capacity of up to 14 377 mAh g⁻¹ at 100 mA g⁻¹ and remained stable over 54 cycles at 500 mA g⁻¹ (with a 500 mA g⁻¹ cutoff). This approach enables the design of manganese oxide-based cathodes within a conductive MXene scaffold for high-performance Li–O₂ batteries.