Alkaline treatment assisted construction of N-MoCT-SnS@rGO aerogels for fast potassium-ion battery.

The development of high-performance potassium-ion batteries (PIBs) are plagued by favorable anode materials which could accommodate the large-sized K ion, achieving fast charging/discharging kinetics and superior cycle life simultaneously. In the present work, we propose a novel three-dimensional hybrid aerogel, N-MoCT-SnS@rGO, in which SnS nanosheets were uniformly anchored onto the elastic and conductive N-MoCT MXenes framework and subsequently encapsulated with reduced graphene oxide (rGO). SnS presents inherent layered configuration and low operating voltage while this unique aerogel architecture could simultaneously improve conductivity, structural integrity, and interfacial contact as well as provide multiple ion/electron transport channels. The N-MoCT-SnS@rGO composite demonstrates superior potassium storage performance, delivering a high reversible capacity of 478 mAh g at 0.1 A g with remarkable cycling stability (303 mAh g retained at 0.5 A g after 1000 cycles), along with exceptional rate capability. The N-MoCT-SnS@rGO electrode exhibits a K diffusion coefficient (D) two orders of magnitude greater than conventional SnS counterparts, demonstrating enhanced ionic transport kinetics, confirming the fast transport kinetics enabled by 3D aerogel architecture. Furthermore, ex situ HRTEM and XRD analysis at different charge/discharge stages elucidate the conversion reaction-based potassium storage mechanism. This study presents a generalized approach to constructing hybrid aerogels with MXenes and transition metal dichalcogenides, offering a versatile way for advanced PIB anode design.