Unlocking Superior Lithium Storage via Synergistic Confinement: Metal-Organic Frameworks Derived Carbon-Confined Metal Sulfides

Abstract

Metal-organic frameworks (MOFs) derived materials, such as transition metal sulfides (TMSs) are attracting much attention for their high theoretical specific capacity as anodes for lithium-ion batteries (LIBs). Herein, the core–shell structured anode, comprising a Cu9S5 core and a Co3S4 shell embedded in nitrogen-doped carbon (NC) (Cu9S5/NC@Co3S4/NC) is developed by combining the calcination and sulphuration treatments of Cu-BTC@ZIF-67 precursor. In the composite, both Cu9S5 and Co3S4 exhibit high electrochemical reaction activities. Moreover, the sulfides are in-situ combined with the porous nitrogen-doped carbon to realize an integrated structure, which efficiently alleviate their aggregation and volume variations during the charging and discharging processes. Integrating the good reactivity and structural stability of Cu9S5/NC@Co3S4/NC anodes, it demonstrates high capacity (1067.3 mAh g-1 at 0.1 A g-1), even at 5 A g-1, the Cu9S5/NC@Co3S4/NC anode shows negligible capacity degradation and maintains at 500 mAh g-1 after 500 cycles. This study proposes an effective strategy to engineer high-performance sulfide-based anodes for LIBs, as evidenced by their superior electrochemical performance.