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Silica Wastes to High‐Performance Lithium Storage Materials: A Rational Designed Al 2 O 3 Coating Assisted Magnesiothermic Process
Author(s) -
Li Bo,
Qi Rongrong,
Zai Jiantao,
Du Feihu,
Xue Chi,
Jin Ying,
Jin Chengyou,
Ma Zifeng,
Qian Xuefeng
Publication year - 2016
Publication title -
small
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.785
H-Index - 236
eISSN - 1613-6829
pISSN - 1613-6810
DOI - 10.1002/smll.201601914
Subject(s) - materials science , anode , coating , fabrication , void (composites) , composite material , chemical engineering , electrode , medicine , chemistry , alternative medicine , pathology , engineering
Si/C yolk–shell structures have been developed to deal with the major issues associated with Si anodes: the huge volume changes and the low electrical conductivity. However, the fabrication process often involves expensive starting materials and/or simultaneously generates insulated SiC, which is harmful for Si anodes. Here, silica wastes from the optical fibers industry are used as starting materials to prepare high performance Si/C materials with Si@void@C yolk–shell structure via a rational designed Al 2 O 3 coating assisted magnesiothermic process. The obtained yolk–shell Si@void@C materials have a capacity of more than 1450 mA h g −1 after 100 cycles at 0.4 A g −1 . Thanks to the easily coated and removed Al 2 O 3 layer, the general formation of SiC can be avoided which is beneficial for improving the rate performances, and a capacity of ≈800 mA h g −1 is still kept after 200 cycles at a high rate of 10 A g −1 with a low capacity loss of 0.08% per cycle.