Self‐Assembly of Transition Metal Oxide Nanostructures on MXene Nanosheets for Fast and Stable Lithium Storage

TLDR

MXenes, a newly unveiled class of 20+ 2D transition metal carbides, nitrides, and carbonitrides, are flexible and conductive, positioning them to compete with graphene and other 2D materials in many applications. The authors present a general self‑assembly route that deposits TiO₂ nanorods and SnO₂ nanowires onto Ti₃C₂ MXene nanosheets via van der Waals interactions, where the MXene substrate enables reversible electron and ion transport and prevents TMO aggregation, while the TMO nanostructures act as spacers to keep the MXene sheets from restacking and preserve active surface area. The resulting TiO₂/MXene and SnO₂/MXene heterostructures exhibit superior high‑rate performance, providing short lithium diffusion pathways and additional active sites, and are promising high‑power and high‑energy anode materials for lithium‑ion batteries.

Abstract

Abstract Recently, a new class of 2D materials, i.e., transition metal carbides, nitrides, and carbonitrides known as MXenes, is unveiled with more than 20 types reported one after another. Since they are flexible and conductive, MXenes are expected to compete with graphene and other 2D materials in many applications. Here, a general route is reported to simple self‐assembly of transition metal oxide (TMO) nanostructures, including TiO 2 nanorods and SnO 2 nanowires, on MXene (Ti 3 C 2 ) nanosheets through van der Waals interactions. The MXene nanosheets, acting as the underlying substrate, not only enable reversible electron and ion transport at the interface but also prevent the TMO nanostructures from aggregation during lithiation/delithiation. The TMO nanostructures, in turn, serve as the spacer to prevent the MXene nanosheets from restacking, thus preserving the active areas from being lost. More importantly, they can contribute extraordinary electrochemical properties, offering short lithium diffusion pathways and additional active sites. The resulting TiO 2 /MXene and SnO 2 /MXene heterostructures exhibit superior high‐rate performance, making them promising high‐power and high‐energy anode materials for lithium‐ion batteries.