A Nanocomposite of Si@C Nanosphere and Hollow Porous Co₉S₈/C Polyhedron as High‐Performance Anode for Lithium‐Ion Battery

Abstract

Silicon (Si) is regarded as one of the most promising anode materials for lithium-ion batteries (LIBs) due to its high capacity and low working voltage. However, dramatic volume expansion and inferior electrical conductivity greatly impede the commercial use of Si anodes. Herein, we design and synthesize a novel nanocomposite of Si nanosphere coated by carbon (Si@C) and hollow porous Co 9 S 8 /C polyhedron (Si@CÀ Co 9 S 8 /C). The hollow porous Co 9 S 8 /C derived from Co-based zeolitic imidazolate framework can serve as a buffering matrix to accommodate the volume expansion of Si, which is beneficial to improve the cycle performance. The vast conductive carbon layer originated from Co 9 S 8 /C and Si@C plays a key role in accelerating the electron transfer and lithium ion transport kinetics, which can significantly enhance the rate performance. As a result, the Si@CÀ Co 9 S 8 /C anodes deliver stable cycle performance with a reversible capacity of 1399 mA h g À 1 after 200 cycles at 100 mA g À 1 , improved rate performance and high Coulombic efficiency. This simple route sheds light on designing Si-based composites for LIBs anodes.

Porous carbon-confined CoxSy nanoparticles derived from ZIF-67 for boosting lithium-ion storage

“…The lattice spacings of 0.28 nm and 0.18 nm are found in Co x S y (700) ( Fig. 4h ), corresponding to the (440) crystal plane of Co 9 S 8 and the (311) crystal plane of Co 4 S 3 , 31–33 respectively. The energy dispersive X-ray (EDS) spectrum of Co x S y (700) is shown in Fig.…”

Co9S8/Porous Carbon Catalysts Boosting Lithium–Sulfur Batteries: NaCl Assisted-Carbothermal Reduction Preparation and Distribution of Relaxation Time Technique Assessment

“…Many sulfuration approaches have been employed to prepare TMS/C composites; among them, metal precursors (metals, metallic nitrates, chlorides, etc. ), sulfur sources (sulfur powder, H 2 S, thioacetamide, thiourea, , Na 2 S, , Na 2 SO 4 , etc. ), and carbon substrates were used by different reaction approaches (solvothermal/hydrothermal, , solid-state reaction, electrochemical deposition, etc.).…”

Extreme Rate Capability Cycling of Porous Silicon Composite Anodes for Lithium‐Ion Batteries

“…Silicon‐based anodes also suffer from high irreversible capacity loss due to unstable solid electrolyte interphase (SEI), low Coulombic efficiency, and poor capacity retention at high rates [8–10] . Several solutions to combat these issues have been proposed including the use of nanowires, nanoparticles, and nanostructures to reduce strain from volume expansion, [11–17] conductive binders to prevent the loss of contact, [18,19] and suitable electrolytes to form a stable SEI [20–22] …”