Carbon nanotube tissue as anode current collector for flexible Li-ion batteries—Understanding the controlling parameters influencing the electrochemical performance

In an attempt to upgrade the performance of lithium (Li)-ion batteries, carbon nanotubes (CNTs) have been suggested as a high-energy anode material. However, CNTs induce high irreversible capacity loss during the first cycle of the battery, which still poses a scientific challenge. This study explores CNT tissue as a flexible light-weight alternative to the copper (Cu) foil as an anode current collector in Li-ion batteries, employing graphite active material. The study demonstrates the impact of the graphite mass loaded on the anode performance and suggests that with the increase in the graphite mass, the irreversible capacity loss is considerably decreased. At sufficiently high graphite loadings, the performance during the first cycle becomes comparable to that of an anode utilizing the Cu current collector. This research also presents several distinct chemical pretreatments to the tissue, aiming to further decrease the irreversible capacity loss. It is suggested that this goal may be accomplished by washing the CNT with sulfuric acid prior to anode preparation, prompting better performance.