PCBM Functionalized WS<sub>2</sub> Hybrid Nanostructures for High Performance Li-Ion Battery Anodes: Toward Binder-Free Electrodes
Bikram Mondal, Ameer Azam, Shahab Ahmad
Abstract
To mitigate technical challenges associated with tungsten disulfide (WS 2 ) 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 WS 2 nanoflakes and multiwalled carbon nanotubes (MWCNTs), which results in formation of WS 2 hybrid nanostructures. Functionalization is confirmed by various optical and structural studies. PCBM worked as a conducting bridge between WS 2 hexagonal nanoflakes and MWCNTs and thus reduced the junction resistance significantly, as well as reduced the agglomeration and pulverization of WS 2 nanoflakes, which in turn improved the performance of WS 2 anodes. The demonstrated WS 2 –PCBM/MWCNT hybrid nanostructure-based anode delivered an excellent average discharge specific capacity of ∼687.14 mAh g –1 at current density of 0.5 A g –1 for 50 cycles with initial Coulombic efficiency of ∼81% and significant rate performance. The WS 2 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 ∼485.73 mAh g –1 . In addition, the PVDF binder-free WS 2 –PCBM/MWCNT hybrid anode has displayed an average discharge specific capacity of ∼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.