MnOOH nanorods as high-performance anodes for sodium ion batteries

MnOOH nanorods, which were prepared using a hydrothermal method, have been used for the first time as anode materials for sodium ion batteries. The as-prepared MnOOH nanorods with lengths of 1.2-3.7 μm and diameters of 60-90 nm delivered high performance of reversible electrochemical Na/Na⁺ storage such as an initial discharge capacity of 485.5 mA h g^-1 at 80 mA g^-1, a high initial Coulombic efficiency of 86.7% and a low average potential polarization of 0.36 V. Instrumental analyses with ex situ XRD, TEM and XPS show that the sodium storage mechanism in MnOOH can be related to the reversible formation of MnO and NaOH. This work demonstrates that cheap MnOOH nanorods are potential anode materials for SIBs.