Effect of Carbon Nanotubes Conductors on Electrolyte Wettability and Electrochemical Performance of Lithium-Ion Battery Electrodes.

Abstract

Electrolyte wettability significantly effects the electrochemical performance of lithium-ion batteries (LIBs). In this study, buoyancy testing is employed to accurately measure the force-time curve of electrolyte penetration into the electrodes and thereby calculate the wettability rate. Electrochemical performance is comprehensively evaluated through CR2025 coin half-cell testing, four-point probe analysis, and C-rate cycling experiments. The effects of conductive agent content, morphology, and size on wettability, conductivity and electrochemical performance are investigated. The results show that carbon nanotube (CNT) conductive agent have strong effect on electrolyte wettability, conductivity, and electrochemical performance. Specifically, electrodes with 3 % CNT content show a 48.9 % increase in wettability, a 95.7 % reduction in electrode resistance, and a 10 % increase in cycle life compared to 1 % CNT. The results show that wettability and conductivity have an equally important effect on electrochemical properties. Larger CNT sizes improve wettability but increase electrode resistance, negatively impacting LIB performance. CNT conductive agents facilitate electrolyte movement along the nanotubes, reducing tortuosity and enhancing wettability. Optical observation of the wetting process on the surface and cross-section of the pure conductive agent electrode strongly supports this conclusion. These results provide valuable insight into optimizing LIB performance by manipulating CNT properties and incorporating them as conductive agents.