Toward a high-performance Li-ion battery: Constructing a Co1−xS/ZnS@C composite derived from metal-organic framework @3D disordered polystyrene sphere template

Abstract

Composites are usually better than a single material because they combine advantages of their component materials and, as a result, achieve better performance. Using a high temperature sulfuration process, a Co1−xS/ZnS@C composite was successfully synthesized by using a 3D disordered polystyrene spheres (PS) template coated on metal-organic framework (ZIF) precursor. The Co1−xS/ZnS in the composite was firmly encapsulated by C that came from the 3D disordered PS template. The carbon can efficiently reduce the volume expansion triggered by metal sulfide particles during the charge/discharge process. Furthermore, due to a synergistic effect between the composite's components, the Co1−xS/ZnS@C composite displays better cycling performance and rate capacity compared to Co1−xS@C and ZnS@C. The Co1−xS/ZnS@C composite electrode showed a higher stable capacity of ~586 mAh g−1 after ~100 cycles with a current density is 0.3 A/g and it also exhibited a more excellent rate capability compare with Co1−xS@C and ZnS@C. Keywords: Composite, Lithium ion battery, ZnS