Silicon delithiation

Amorphous silicon demonstrates different features than those of crystalline silicon when subjected to lithiation at room temperature. 8tudies on an amorphous silicon thin-film anode prepared by magnetron sputtering and an amorphous silicon anode obtained through chemical delithiation of Lii2Si7 phase show two distinctive. 

A silicon/disordered-carbon powder was applied as the negative electrode material in Li-ion batteries. The thermal characteristics of the Si/C electrode (with or without the electrolyte) were investigated by DSC [9]. Both lithiated (with capacity of 1120 mAh/g) and delithiated Si/C electrode powders showed exothermic peaks in DSC curves due to the reactions between the Li in the electrode and the SEI. The lithiated electrode caused much larger exothermic heat them the delithiated one, especitilly when they were mixed with the electrolyte. 

To limit the effects of dramatic volume changes between lithiation and delithiation and the SETs resulting instability, different strategies have been put in place, such as silicon nano-architecturing, a specific electrode formulation and the use of electrolyte additives as described above for carbonaceous materials. 

Since silicon suffers from the huge change of volume upon lithiation-delithiation, SiO has been viewed as an alternative. SiO is a mixture of amorphous Si and amorphous silica. Lithium oxide (Li20) is generated during the first lithiatirMi ... 

McDowell MT, Lee SW, Wang C, Cui Y (2012) The effect of metallic coatings and crystallinity on the volume expansion of silicon during electrochemical lithiation/ delithiation. Nano Energy 1 401 10... 

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