Binder-free LiNi0.8Mn0.1Co0.1O2 electrode enabled by single-walled carbon nanotube coating for Li-ion batteries

Abstract

Herein, we report a solvent-free preparation procedure for a binder-free LiNi_0.8Mn_0.1Co_0.1O₂ (NCM811 or NMC811) positive electrode consisting of only 0.2 wt% single-walled carbon nanotubes (SWCNTs) and 99.8 wt% NCM811. SWCNTs form a three-dimensional conductive network within NCM811 particles, facilitating electron transfer across the NCM811 electrode, while maintaining high content of the active material. The binder-free NCM811-SWCNT electrode provides a high discharge specific capacity of ~190 mAh g⁻¹ at 0.2C current rate retaining 38 % more of the initial capacity than a conventional electrode after 200 charge-discharge cycles at 1C. Electrochemical techniques such as operando X-ray diffraction and dilatometry has been applied for the first time to gain a deeper understanding of binder-free electrode structure evolution induced by electrochemical transformations. The data obtained demonstrates a good agreement between macroscopic and microscopic parameters changes for a NCM-SWCNT electrode.