Three-Dimensional Bi₂S₃ Nanoflowers with Built-In MXene Nanosheets for Reversible Lithium-Ion Storage with Enhanced Performance and Kinetics

Bismuth sulfide (Bi 2 S 3 ) has been considered as a potential anode candidate for high-energy lithium-ion batteries (LIBs) due to its high theoretical Li-ion storage capacity. However, the Bi 2 S 3 anode suffers from rapid capacity fading under prolonged electrochemical cycling, owing to reaction strain and drastic volume expansion during the charge/discharge processes. Herein, we report an MXene-integrated structure design for the Bi 2 S 3 nanoflowers through an in situ hydrothermal method, resulting in titanium carbide (Ti 3 C 2 )-supported Bi 2 S 3 nanoflowers (Bi 2 S 3 @Ti 3 C 2 ) with proper structural integrity via chemical interaction between two components. The Bi 2 S 3 @Ti 3 C 2 nanocomposite anode significantly outperformed the pristine Bi 2 S 3 nanoflowers in terms of lithium storage performance, retaining a capacity of approximately 335 mAh g –1 at 200 mA g –1 and 301 mAh g –1 at a higher current density of 1000 mA g –1 over 100 cycles. Moreover, the composite material Bi 2 S 3 @Ti 3 C 2 also delivers a cycling performance of 181.3 mAh g –1 over 400 cycles with a high mass loading. Enhanced lithium storage kinetics of the composite Bi 2 S 3 @Ti 3 C 2 has also been demonstrated by the galvanostatic intermittent titration technique and in situ electrochemical impedance spectroscopic measurements. This work provides structural engineering for ameliorating transition metal chalcogenides as high-capacity anode materials for LIBs with better rate capability and cycling stability.