In situ implanting MnO nanoparticles into carbon nanorod-assembled microspheres enables performance-enhanced room-temperature Na–S batteries

Abstract

The accomplishment of high-performance room-temperature sodium–sulfur (RT Na–S) batteries necessitates multifunctional sulfur electrodes via decent materials design strategies, since they are suffering from a series of critical challenges in S conversion chemistry. Herein, a functionalized S cathode is fabricated through in situ implanting polar MnO nanoparticles into carbon microspheres self-assembled by porous nanorods. The one-dimensional (1D) carbon nanorods can assist in fast electron transfer while nanochannels among the well-aligned nanorods act as pathways for Na ion diffusion. More significantly, the embedded ultrafine polar MnO nanoparticles function as good polysulfide adsorbents due to their strong chemical affinity and can promote conversion kinetics. As such, RT Na–S batteries with the as-designed S cathode achieve great cyclability of 234 mA h g⁻¹ over 1000 cycles at 2 A g⁻¹ and superior rate capability of 418 mA h g⁻¹ at 2 A g⁻¹.