Polymer-Derived Ceramic Functionalized MoS(2) Composite Paper as a Stable Lithium-Ion Battery Electrode

A facile process is demonstrated for the synthesis of layered SiCN-MoS(2) structure via pyrolysis of polysilazane functionalized MoS(2) flakes. The layered morphology and polymer to ceramic transformation on MoS(2) surfaces was confirmed by use of electron microscopy and spectroscopic techniques. Tested as thick film electrode in a Li-ion battery half-cell, SiCN-MoS(2) showed the classical three-stage reaction with improved cycling stability and capacity retention than neat MoS(2). Contribution of conversion reaction of Li/MoS(2 )system on overall capacity was marginally affected by the presence of SiCN while Li-irreversibility arising from electrolyte decomposition was greatly suppressed. This is understood as one of the reasons for decreased first cycle loss and increased capacity retention. SiCN-MoS(2) in the form of self-supporting paper electrode (at 6 mg·cm(−2)) exhibited even better performance, regaining initial charge capacity of approximately 530 mAh·g(−1) when the current density returned to 100 mA·g(−1) after continuous cycling at 2400 mA·g(−1) (192 mAh·g(−1)). MoS(2) cycled electrode showed mud-cracks and film delamination whereas SiCN-MoS(2) electrodes were intact and covered with a uniform solid electrolyte interphase coating. Taken together, our results suggest that molecular level interfacing with precursor–derived SiCN is an effective strategy for suppressing the metal-sulfide/electrolyte degradation reaction at low discharge potentials.