A Binder-Free Nickel-Rich Cathode Composite Utilizing Low-Bundled Single-Walled Carbon Nanotubes

In this study, the performance of a binder-free LiNi_0.6Co_0.2Mn_0.2O₂ (NMC622) positive electrode utilizing single-walled carbon nanotubes (SWCNTs) is investigated and compared to the conventional state-of-the-art NMC622 composite positive electrode. The binder-free electrode has been prepared without using toxic and expensive N-Methyl-2-pyrrolidone (NMP) solvent and it is free-standing that allows a wider range of applications such as flexible devices. Electrochemical techniques such as cyclic voltammetry, electrochemical impedance spectroscopy, and galvanostatic charge–discharge reveal that the binder-free positive electrode performance is similar to the conventional composite cathodes, deducing that only ≈1% of SWCNTs perform well not only as a conductive agent but also as a binder. The NMC622 composite electrode with SWCNTs provided specific capacity of 135.8 mAh g⁻¹ at a 5C rate during discharge, with above 97% capacity retention after the rate capability test in a half cell.