title: Core-shell Si/C nanospheres embedded in bubble sheet-like carbon film with enhanced performance as lithium ion battery anodes.
abstract: Due to its high theoretical capacity and low lithium insertion voltage plateau, silicon has been considered one of the most promising anodes for high energy and high power density lithium ion batteries (LIBs). However, its rapid capacity degradation, mainly caused by huge volume changes during lithium insertion/extraction processes, remains a significant challenge to its practical application. Engineering Si anodes with abundant free spaces and stabilizing them by incorporating carbon materials has been found to be effective to address the above problems. Using sodium chloride (NaCl) as a template, bubble sheet-like carbon film supported core-shell Si/C composites are prepared for the first time by a facile magnesium thermal reduction/glucose carbonization process. The capacity retention achieves up to 93.6% (about 1018 mAh g(-1)) after 200 cycles at 1 A g(-1). The good performance is attributed to synergistic effects of the conductive carbon film and the hollow structure of the core-shell nanospheres, which provide an ideal conductive matrix and buffer spaces for respectively electron transfer and Si expansion during lithiation process. This unique structure decreases the charge transfer resistance and suppresses the cracking/pulverization of Si, leading to the enhanced cycling performance of bubble sheet-like composite.
authors.affiliation: Functional Thin Films Research Center, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China; Department of Physics and Materials Science, Center of Super-Diamond and Advanced Films (COSDAF), The City University of Hong Kong, Hong Kong SAR, China.
authors.forename: Wenyue
authors.initials: W
authors.lastname: Li
authors.forename: Yongbing
authors.initials: Y
authors.lastname: Tang
authors.forename: Wenpei
authors.initials: W
authors.lastname: Kang
authors.forename: Zhenyu
authors.initials: Z
authors.lastname: Zhang
authors.forename: Xia
authors.initials: X
authors.lastname: Yang
authors.forename: Yu
authors.initials: Y
authors.lastname: Zhu
authors.forename: Wenjun
authors.initials: W
authors.lastname: Zhang
authors.forename: Chun-Sing
authors.initials: CS
authors.lastname: Lee
keywords: carbon films; core-shell structures; energy storage; lithium ion batteries; synergistic effects