Synthesis and characterization of MnCo2O4 microspheres based air electrode for rechargeable sodium-air batteries

In this work, the nanosized porous MnCo2O4 microspheres were synthesized by a hydrothermal method and their electrochemical behaviors were investigated based on a carbon supported composite air electrode for rechargeable sodium-air batteries. Under dry air test condition, the MnCo2O4/C air electrode demonstrated a stable working voltage of around 2.1 V vs. Na+/Na and a high initial discharge capacity of 7709.4 mA h g−1, based on the active material mass, at a current density of 0.1 mA cm−2. By a limit on the depth of discharge, the cell exhibited a specific capacity of 1000 mA h g−1 with a high cycling stability up to 130 cycles. The considerable electrocatalytic activity suggests that the as-proposed MnCo2O4 is a highly efficient catalyst as air electrode for rechargeable sodium-air batteries.