Open AccessType I Clathrates as Novel Silicon Anodes: An Electrochemical and Structural Investigation
Author(s) -
Li Ying,
Raghavan Rahul,
Wagner Nicholas A.,
Davidowski Stephen K.,
Baggetto Loïc,
Zhao Ran,
Cheng Qian,
Yarger Jeffery L.,
Veith Gabriel M.,
EllisTerrell Carol,
Miller Michael A.,
Chan Kwai S.,
Chan Candace K.
Publication year - 2015
Publication title -
advanced science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.388
H-Index - 100
ISSN - 2198-3844
DOI - 10.1002/advs.201500057
Subject(s) - silicon , anode , electrochemistry , materials science , lithium (medication) , clathrate hydrate , amorphous solid , amorphous silicon , chemical engineering , nanotechnology , crystalline silicon , crystallography , chemistry , hydrate , electrode , metallurgy , organic chemistry , medicine , engineering , endocrinology
Silicon clathrates contain cage‐like structures that can encapsulate various guest atoms or molecules. An electrochemical evaluation of type I silicon clathrates based on Ba 8 Al y Si 46− y as the anode material for lithium‐ion batteries is presented here. Postcycling characterization with nuclear magnetic resonance and X‐ray diffraction shows no discernible structural or volume changes even after electrochemical insertion of 44 Li (≈1 Li/Si) into the clathrate structure. The observed properties are in stark contrast with lithiation of other silicon anodes, which become amorphous and suffer from large volume changes. The electrochemical reactions are proposed to occur as single phase reactions at approximately 0.2 and 0.4 V versus Li/Li + during lithiation and delithiation, respectively, distinct from diamond cubic or amorphous silicon anodes. Reversible capacities as high as 499 mAh g− 1 at a 5 mA g −1 rate were observed for silicon clathrate with composition Ba 8 Al 8.54 Si 37.46 , corresponding to ≈1.18 Li/Si. These results show that silicon clathrates could be promising durable anodes for lithium‐ion batteries.