Multidimensional synergistic architecture of Ti3C2 MXene/CoS2@N-doped carbon for sodium-ion batteries with ultralong cycle lifespan

Abstract Sodium-ion batteries (SIBs) based on conversion-type anode materials exhibit great prospect in the field of large-scale energy storage because of their superior sodiation capacities and low costs. However, poor charge transfer kinetics and short cycle life induced by huge volume change remain two great challenges. Herein, a multidimensional synergistic structure of few-layered Ti3C2 MXene/CoS2@N-doped porous carbon (f-Ti3C2/CoS2@NPC) is rationally designed as SIBs anodes, where N-doped porous carbon matrix-encapsulated ultrafine CoS2 nanoparticles are anchored on few-layered Ti3C2 MXene via Ti O C bonds. The synergistic effects among each component greatly inhibit the aggregation of CoS2 nanoparticles (CoS2 NPs), readily build a long-range electron/Na+ conductive network and effectively provide a dual protection effect on CoS2 NPs during sodiation/desodiation process. Consequently, the f-Ti3C2/CoS2@NPC anode delivers a high-rate performance (282.6 mAh g−1 at 10 A g−1) and superior cyclability (200.6 mAh g−1 at 2 A g−1 after 1500 cycles). Furthermore, Na3V2(PO4)3//f-Ti3C2/CoS2@NPC full cells can release a high reversible capacity and good cyclability (325.8 mAh g−1 at 200 mA g−1 after 50 cycles), demonstrating great potential in practical application. This work further broadens the scope of multidimensional synergistic architectures and may inspires more research on MXene-based multidimensional structure for high-performance SIBs.