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

Abstract

In this study, the performance of a binder‐free LiNi0.6Co0.2Mn0.2O2 (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.