Layered Bimetallic Metal-Organic Material Derived Cu2SnS3/SnS2/C Composite for Anode Applications in Lithium-Ion Batteries

Here, we report the synthesis of a bimetallic 2D interpenetrated metal-organic material (MOM) and its use as a sacrificial precursor for the formation of a Cu₂SnS₃/SnS₂/C composite. The one-step sulfurisation of the novel Sn/Cu-MOM represents a facile method for the preparation of an effective anode material for Li-ion battery applications. The Cu₂SnS₃/SnS₂/C composite was characterised by XRD, TGA, TEM and SEM. Electrochemical analysis was conducted on SnCu₂SnS₃/SnS₂/C anodes in half cell configurations between 0–3 V and 0–1 V. Anodes cycled between 0–1 V exhibited markedly more stable capacity retention (315 mAh/g after 100 cycles), as only alloying of the Li with Sn took place within this potential window, compared to a combination of conversion and alloying for the wider potential range. This stability of the Li alloying based capacity was further enhanced by replacing the planar Cu foil with a rough dendritic Cu foil as the current collector, resulting in an improved capacity retention of 84 % after 100 cycles.