Enhancing Lithium‐Ion Battery Performance with Ni₁−_xFe_xS‐Biocarbon Composites: Improving Cycle Stability and Rate Capability through Multilayered Biocarbon Nanosheet Formation and Fe Doping

Abstract

Given the growing demand for high‐performance, stable, eco‐friendly, and cheap lithium‐ion batteries (LIBs), the development of affordable and environmentally friendly high‐performance anode materials for LIBs has garnered considerable attention. Herein, to address this need, NiS (known for its high theoretical capacity) was grown on a porous biocarbon (BC) matrix to afford a highly conductive LIB anode material capable of accommodating the charge/discharge‐induced volume changes and thus ensuring cycle stability. The cycling performance of this material (NiS–BC) was further enhanced by doping with Fe. The best‐performing (Ni0.8Fe0.2S–BC) anode demonstrated an initial discharge capacity of 1,374.4 mAh g−1 at 0.5 A g−1, which further increased to 1,796.4 mAh g−1 after 100 cycles, and the origins of this high performance were probed by instrumental analysis. The results contribute to the development of next‐generation LIBs for applications requiring high capacity, high output, and long‐term cycle stability, such as electronic devices, electric vehicles, and energy storage systems. Moreover, the use of BC aligns with a prominent trend in modern battery research, namely, the development of secondary batteries simultaneously exhibiting high performance and sustainability.