Engineering the Catalytic Superlattices for Highly Reversible Sodium‐Ion Storage with A high Compositional Conversion Degree

Abstract A major obstacle of transition metal disulfides in sodium‐ion batteries is compositional irreversible conversion, leading to fast capacity decay. Here, we propose to engineer a catalytic superlattice structure for achieving a record‐high compositional reversible conversion degree (≈100 %). The superlattice is constructed by alternately stacking MoS 2 layers and nitrogen/oxygen co‐doped reduced graphene oxide‐supported single‐atom metal layers (MoS 2 /M‐ONG SL, M=Fe, Co, Ni, Cu, Zn) with 100 % MoS 2 /M‐ONG interfaces, in which the metal atoms bridge the two layers through S−M‐O chemical bonds. Using MoS 2 /Co‐ONG SL as a model, the unique superlattice structure shows excellent electron and Na + transport properties during discharge and charge. Moreover, the Co‐ONG boosts Na 2 S adsorption and decomposition by forming Co‐3d and S‐3p hybridization. As a result, the MoS 2 /Co‐ONG SL shows a high compositional reversible conversion degree(≈100 %), as proven by a series of in‐/ex situ spectroscopic analyses. As a result, the MoS 2 /Co‐ONG SL exhibits a stable cycling stability of 300.7 mAh g −1 after 2000 cycles at 2 A g −1 , with an ultrasmall capacity decay rate of 0.41 % per 100 cycles. This work offers a noteworthy perspective on the design and fabrication of conversion‐type materials, emphasizing the crucial role of interface engineering in achieving excellent bidirectional reaction kinetics.