Novel Design of Silicon Electrode Based on Stainless Steel Metal Fibril As Current Collector for Lithium-Ion Batteries

Abstract

Silicon (Si) has been one of the promising anode materials targeting for the next high capacity lithium-ion batteries (LIBs). Lithium ions are reversibly stored in Si based on an alloy mechanism, and thus Si can possess much higher level of theoretical capacity (4,200mAh/g), over 10 times, compared to that of commercial graphite (372mAh/g) [1]. Unfortunately, however, inherent low electric conductivity and poor cell performance has hindered commercialization of Si for a decade.In order to solve these drawbacks, nano-sized and nano-structured silicon has been introduced. In this work, we developed novel design silicon electrode based on stainless steel metal fibril. In order to achieve this goal, we introduced 3-D current collectors based on stainless steel metal fibril (SF) to increase free volume within Si anodes [2] Subsequently, Si coated by radio frequency (RF) magnetron sputtering method. Coating thickness and loading amount of Si active material on SF was controlled around 1μm and 0.2mg/cm2, respectively. Electrochemical performance of as-prepared SF based Si anode was evaluated using charge-discharge machine (PNE, Koran). Surface changes of as-prepared Si anodes were monitored by Scanning Electron Microscope (TOPCOM, japan)-Energy Dispersive X-ray Spectroscopy (AMETEK, USA).