Rapid synthesis of activated carbon/bismuth sulfide hybrid anode for next-generation lithium-ion batteries

In this study, we report a composite of activated carbon/bismuth sulfide (AC/Bi₂S₃) as a high-performance anode material for lithium-ion batteries (LiBs). Bi₂S₃ was synthesized via a microwave-assisted hydrothermal route, which offers a rapid, energy-efficient, and scalable approach to produce nanostructured materials. AC/Bi₂S₃ electrodes were fabricated in varying ratios using physical mixing and doctor blade coating to identify their optimal composition. The AC/Bi₂S₃_9:1 composite achieved an ultrahigh specific capacity of 1663.92 mAh/g at 0.2 A/g, which was attributed to the synergistic effect of the rich redox-active sites of Bi₂S₃ and the high conductivity and structural buffering capability of AC. Its coulombic efficiency improved significantly from 89.47 % in the first cycle to 99 % after 100 cycles. Notably, it retained 422.98 mAh/g at 0.2 A/g (58.15 % capacity retention) after 100 cycles, indicating outstanding cyclic stability. The electrode also demonstrated excellent rate capability, sustaining high charge-discharge capacities across varying current densities. In a practical full-cell configuration, it delivered 152.27 mAh/g at 0.2 A/g with 67.22 % retention, highlighting its real-world applicability. This study not only establishes AC/Bi₂S₃ as a high-performance anode candidate for next-generation LiBs but also validates the potential of microwave-assisted hydrothermal synthesis for eco-friendly and scalable energy storage material production.