Silicon-coated multi-walled carbon nanotube (MWCNT) tissues as flexible free-standing anodes for advanced Li-ion batteries

Further progress in flexible electronic devices, such as soft electronics, rollable and wearable displays, and bendable smartphones, implies essential evolution in the field of flexible energy storage devices. In this regard, multi-walled carbon nanotube (MWCNT) tissue that has a strong presence among the most lightweight, robust, and flexible materials of nowadays is among the leading candidates to be applied as a flexible anode in rechargeable lithium-ion batteries (LIBs). However, pristine MWCNT tissue anodes suffer from extremely high (ca. 1000 mAhg⁻¹) irreversible capacity in the first formation cycle, which prevents them from entering the market. Here, we report the Si-coated MWCNT tissue composite material fabricated via magnetron sputtering for the application as a flexible freestanding anode for advanced LIBs. Such composite electrode allows as high as 94% of coulombic efficiency after the initial ten formation cycles as well as a remarkable improvement of gravimetric capacity from 109 to 290 mAhg⁻¹ as compared with uncoated MWCNT tissue. The suggested synthetic process is simple and inexpensive, rendering the hybrid composite anode as an appealing one for flexible LIB applications. Graphical Abstract: (Figure presented.)