Proceedings of 26th Annual Technological Advances in Science, Medicine and Engineering Conference 2022

Unlocking the potential of high-content silicon anodes for lithium-ion batteries
Jaegeon Ryu
Abstract
As a promising alternative to the conventional graphite anode, the high theoretical capacity (~3500 mAh/g) and low working potential (<0.4 V vs. Li+/Li) of silicon (Si) anodes could resolve the performance limit of commercial lithium-ion batteries (LIBs), while huge volumetric deformation of Si upon Li-ion insertion poses a major challenge toward an upcoming generation of electric vehicles. There have been extensive studies to directly implement the pure Si anodes to the market still compositing the Si with conductive carbon counterparts (i.e., graphite) either in physical mixing or surface protection predominates at a micro- or nanoscale. However, degradation of Si anodes prohibits the formation of a stable solid electrolyte interphase layer onto the graphite surface, and pulverized Si particles interrupt the ionic and electronic transport pathway. In this presentation, two different approaches to allow for the use of high-content Si anodes will be introduced. The first part will cover hollow Si microparticles with multiscale pores and infinitesimal sulfur doping feature high electronic and ionic conductivity due to the simultaneous substitutional and interstitial doping methods to achieve both fast-charging and high-energy-density batteries. The other part will deal with atomically shuffled Si-C composite anodes synthesized via thermolysis and mechanical dehydrogenation. The electrochemical lithium insertion drives the dissociation of disordered Si-C bonds and the formation of subnanometer Si dispersed in a microporous carbon framework. Resultingly, the electrode and specimen-level stability have been achieved.

Last modified: 2022-08-20
Building: TASME Center
Room: Engineering Hall
Date: August 27, 2022 - 09:00 AM – 09:20 AM

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