Fig. 2: Electrochemical properties of the molybdenum nitrides in RT Na–S batteries.

a Cycling performance and CE for the three sulfur electrodes at 1 C. b Comparison of cycle number and capacity retention of recently reported RT Na–S cells with the present work, in which darker-color refers to greater specific current. c Rating capacities for S/Mo5N6, S/MoN, and S/Mo2N. d Linear relationship between peak current (ip) and square root of scan rate (v1/2) for the three sulfur electrodes. e Energy profile for sodium ion diffusion on Mo5N6 (0 0 4) facet, MoN (0 0 2) facet, and Mo2N (1 0 0) facet.