PCBM Functionalized WS2 Hybrid Nanostructures for High Performance Li-Ion Battery Anodes: Toward Binder-Free Electrodes

To mitigate technical challenges associated with tungsten disulfide (WS2) anodes for lithium-ion batteries (LIBs) application, we demonstrate a novel approach of using phenyl-C-61-butyric acid methyl ester (PCBM) to effectively functionalize WS2 nanoflakes and multiwalled carbon nanotubes (MWCNTs), which results in formation of WS2 hybrid nanostructures. Functionalization is confirmed by various optical and structural studies. PCBM worked as a conducting bridge between WS2 hexagonal nanoflakes and MWCNTs and thus reduced the junction resistance significantly, as well as reduced the agglomeration and pulverization of WS2 nanoflakes, which in turn improved the performance of WS2 anodes. The demonstrated WS2-PCBM/MWCNT hybrid nanostructure-based anode delivered an excellent average discharge specific capacity of similar to 687.14 mAh g(-1) at current density of 0.5 A g(-1) for 50 cycles with initial Coulombic efficiency of similar to 81% and significant rate performance. The WS2 hybrid anodes were cycled for 500 cycles at a current density of 1.0 A g(-1) with a stable average discharge specific capacity of similar to 485.73 mAh g(-1). In addition, the PVDF binder-free WS2-PCBM/MWCNT hybrid anode has displayed an average discharge specific capacity of similar to 1224 mAh g(-1) for up to 20 cycles at a current density of 0.1 A g(-1). Our work provides a novel approach by exploiting the utility of PCBM in LIBs.