Atmospheric oxidation effect of silicon–carbon nanotube anode on Li-ion battery performance

Abstract

Secondary energy storage devices are in high demand owing to recent developments in portable electronic devices and electric vehicles. In the last two decades, lithium-ion (Li-ion) battery technology has witnessed phenomenal growth. In order to cope with future requirements and to improve specific capacity, retention ability and life span of the battery, different anode materials, such as carbon nanotube (CNT), tin dioxide (SnO2), silicon (Si) and so on, were investigated. A pure Si-based anode offers maximum theoretical specific capacity of 4200 mAh/g. However, a large volume change (around 400%) during the lithiation–delithiation process hampers its wide acceptance. This problem could be addressed by incorporating different composite anode materials; Si–CNT composite is one of them. Si–CNT composite has shown great promise as a Li-ion battery anode material, but at the same time, the large surface area of Si nanoparticles makes it highly sensitive to atmospheric oxidation. This research work reports an easy and scalable method of synthesis of a Li-ion battery anode using Si–CNT composite and demonstrates the effect of atmospheric oxidation of Si nanoparticles on the performance of the Li-ion battery. The prepared anode was characterized for its structure and electrochemical performance. It offered good initial specific capacity of 663 mAh/g, though this deteriorated owing to surface oxidation.