Multi-walled carbon-nanotube-decorated tungsten ditelluride nanostars as anode material for lithium-ion batteries

Abstract

Abstract Multi-walled carbon-nanotube (MWCNT)-decorated WTe 2 nanostars (WTe 2 @CNT nanocomposites) are to be employed for the first time as anode candidates in the development of lithium-ion (Li-ion) batteries. WTe 2 @CNT nanocomposites deliver a high discharge capacity of 1097, 475, 439, 408, 395 and 381 mA h g −1 with an increasing current density of 100, 200, 400, 600, 800 and 1000 mA g −1 , respectively, while WTe 2 nanostars exhibit a reversible capacity of 655, 402, 400, 362, 290 and 197 mA h g −1 with the aforementioned current densities. Furthermore, WTe 2 @CNT nanocomposites exhibit a superior reversible capacity of 592 mA h g −1 at 500 mA g −1 with a capacity retention of 100% achieved over 500 cycles, while bare WTe 2 nanostars deliver ∼85 mA h g −1 over 350 cycles. This remarkable Li cycling performance is attributed to MWCNTs interconnected with WTe 2 nanostars. In addition, the exposed active interlayers of the WTe 2 nanostars, which are responsible for maintaining the structural integrity of the electrodes, buffer the large volume expansion within the WTe 2 nanostars, avoiding the agglomeration of the particles. The layered WTe 2 nanostars were synthesized via the solution-phase method, and present extremely good possibilities for the scaling-up of Li-ion battery storage systems.