Polymer-Derived Ceramic Functionalized MoS2 Composite Paper as a Stable Lithium-Ion Battery Electrode

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Molybdenum disulfide (MoS2) is a promising material for lithium-ion batteries but suffers from poor cycling stability.
• Electrolyte decomposition and structural degradation limit the performance of MoS2-based electrodes.

Purpose of the Study:

• To develop a facile synthesis method for a SiCN-MoS2 layered structure.
• To investigate the electrochemical performance of SiCN-MoS2 as a thick film electrode in Li-ion battery half-cells.
• To understand the role of SiCN in improving the stability and performance of MoS2 electrodes.

Main Methods:

• Synthesis of SiCN-MoS2 via pyrolysis of polysilazane functionalized MoS2 flakes.
• Characterization using electron microscopy and spectroscopic techniques.
• Electrochemical testing in Li-ion battery half-cells, including cycling stability and capacity retention measurements.

Main Results:

• The SiCN-MoS2 structure exhibited improved cycling stability and capacity retention compared to neat MoS2.
• SiCN effectively suppressed Li-irreversibility arising from electrolyte decomposition, reducing first cycle loss.
• Self-supporting SiCN-MoS2 paper electrodes demonstrated excellent performance, maintaining high capacity even after high current density cycling.
• SiCN-MoS2 electrodes showed a uniform solid electrolyte interphase coating and structural integrity, unlike the delamination observed in MoS2 electrodes.

Conclusions:

• Molecular level interfacing with precursor-derived SiCN is an effective strategy to enhance the electrochemical performance of MoS2.
• The SiCN coating suppresses degradation reactions at low discharge potentials, leading to improved battery longevity and stability.