Title : Synthesis of silicon nanowires as a high performance anode material for lithium ion batteries
Abstract:
Today, Lithium ion batteries have been used extensively in mobile electronic devices. Especially for electric vehicles, usually these kind of batteries are widely implemented. These intensive applications of Lithium ion batteries have motivated the researchers to focus a great deal of attention on their performance improvement. Anode is one of the main components of these batteries, and for a long period of time graphite has been used for this section, offering a specific capacity of 372 mAh/g. On the other hand, Silicon is a high potential material for anodes of Lithium ion batteries, presenting a very high theoretical capacity of 4212 mAh/g, more than 10 times that of graphite. This ability to accept huge amount of Lithium inside its material, results in a high volumetric expansion for Silicon after lithiation that can lead to cracking of the active material, loosing its contact with the current collector and finally degrading the battery performance. Nanostructures of Silicon can significantly help to solve this problem, by providing enough void space between nanowires, in addition to their better tolerance to the volume expansion compared to the bulk material. Here we have synthesized Silicon nanowires on stainless steel substrate, using VLS approach in a CVD system. This structure has been used as a binder-free anode material for Lithium ion battery application. 1 M LipF6 in EC/DEC with 5% FEC have been used as the electrolyte. Lithium ion half-cell have been assembled in a Glove box with Ar ambient with Oxygen and humidity of less than 0.1 ppm. The results show high specific capacity of about 2400 mAh/g.
Audience take away:
- Introduction to Lithium ion batteries will be explained
- Silicon based anode material is introduced as the pioneer anode in the modern Lithium ion batteries
- CVD synthesis of Silicon nanowires is explained, which is one of the important approaches for growth of Si nanostructures.
- These topics are part of the emerging technologies in the Lithium ion battery field, that can help the audience to be familiar with these topics and expand their research or teaching.
- This research subject can lead to having higher performance Lithium ion batteries.
