Large and reversible sodium storage through interlaced reaction design

As most anode materials cannot achieve sodium storage performance close to their theoretical capacity as a result of sluggish reaction kinetics under repeated cycles, herein, we propose an interlaced reaction strategy based on logical component design with a core-shell structure to improve the reversible capacity for sodium storage. Sb₂S₃/MoS₂ and Sb₂S₃/SnS₂ core-shell nanowires (NWs) are demonstrated as proof of concept: first, the theoretical capacity of Sb₂S₃ is in between those of MoS₂ and SnS₂ (Sb₂S₃: 946 mAh/g; MoS₂: 670 mAh/g; SnS₂: 1136 mAh/g); second, the conversion and alloying processes for Sb₂S₃ (voltage range < 0.7 V) are interlaced with the intercalation and conversion processes of MoS₂ but overlap with those of SnS₂. Sb₂S₃/MoS₂ is found having the lowest theoretical capacity but, benefiting by the interlaced reaction, performing the highest reversible capacity in the actual test. As an important factor, the intercalation process of MoS₂, which induces the phase transition of 2H MoS₂ to the 1T phase, interlaces with the conversion and alloying processes of Sb₂S₃ and facilitates the reaction kinetics of the composites. Logical component design based on the interlaced reaction opens a new avenue for developing advanced sodium storage materials.