Ultrathin-Walled Bi S Nanoroll/MXene Composite toward High Capacity and Fast Lithium Storage.

It is extremely important to develop a high energy density power source with rapid charge-discharge rate to meet people's growing needs. Hence, the development of advanced electrode materials is the top priority. Herein, a simple yet elaborate vacuum-assisted room-temperature phase transfer method is reported to transform MXene nanosheets from water into organic solution. Subsequently, an in-situ growth strategy is employed to deposit ultrathin-walled bismuth sulfide (Bi S ) nanorolls on MXene surface to prepare Bi S /MXene composite as an efficient and high-performance anode material for lithium-ion batteries. Attributed to the unique nanoroll-like structure and the strong synergistic effect, the Bi S /MXene-10 composite can deliver the high discharge capacities of 849 and 541 mAh g at 0.1 and 5 A g , respectively. The Bi S /MXene-10 electrode can deliver a high specific capacity of 541 mAh g even after 600 cycles at a large current density of 1 A g , proving the superb cycling stability of the Bi S /MXene-10 composite. Additionally, the simple vacuum-assisted room-temperature phase transfer strategy can enlighten researchers to expand the potential application of MXene. Furthermore, the formation mechanism of Bi S nanorolls is also proposed, which may open a new avenue to design and fabricate other nanoroll-like structures.