A highly efficient cathode catalyst γ-MnO_2@CNT composite for sodium-air batteries

The γ-MnO_2@CNT catalyst was prepared by in situ solid phase synthesis and first applied into sodium-air batteries(SABs). The initial discharge specific capacity of SABs with γ-MnO_2@CNT catalyst can reach 8804 mA h g~(-1) and the overpotential gap is only 140 m V, which is better than the batteries that is catalyzed by α-MnO_2@CNT and pure CNT. Besides, the batteries also exhibit excellent cycle performance, which can keep relatively stable for 246 cycles at 500 mA g~(-1) and 140 cycles at1000 mA g~(-1).