Tetrabutylammonium‐Intercalated 1T‐MoS2 Nanosheets with Expanded Interlayer Spacing Vertically Coupled on 2D Delaminated MXene for High‐Performance Lithium‐Ion Capacitors

Abstract 2D 1T phase MoS 2 (1T‐MoS 2 ) nanosheet with metallic conductivity and expanded interlayer spacing is considered as a highly potential lithium storage electrode material but remains thermodynamic instability in aqueous media, seriously hindering the electrochemical performance. Herein, a versatile strategy is proposed for the preparation of thermodynamically stable 1T‐MoS 2 /MXene heterostructures with the aid of delaminated Ti 3 C 2 T x MXene (d‐Ti 3 C 2 T x ) dispersion containing tetrabutylammonium hydroxide. The 2D d‐Ti 3 C 2 T x provides more uniform nucleation sites for MoS 2 , and the TBA + ions can intercalate into MoS 2 to induce the phase conversion from semiconducting 2H to 1T. Moreover, the electrochemical advantages of 1T‐MoS 2 and d‐Ti 3 C 2 T x can be united by the construction of a well‐organized heterostructure. Outstanding rate performance is realized because of extra‐large interlayer space of 1T MoS 2 with TBA + intercalation and decreased energy barrier for fast Li + diffusion. Subsequently, a lithium‐ion capacitor (LIC) is assembled based on 1T‐MoS 2 /d‐Ti 3 C 2 T x as anode and hierarchically porous graphene nanocomposite with micro/mesoporous structure as a cathode. The LIC exhibits a large energy density up to 188 Wh kg −1 , an ultra‐high power density of 13 kW kg −1 , together with remarkable capacity retention of 83% after 5000 cycles. This study demonstrates the great promise of 1T‐MoS 2 /d‐Ti 3 C 2 T x heterostructures as anode for high‐performance LICs.