Fabrication of a Nondegradable Si@SiO _x /n-Carbon Crystallite Composite Anode for Lithium-Ion Batteries.

ABSTRACT: A Si-based anode maintaining its high electrochemical performance with cycles was prepared for the nondegradable lithium-ion battery. Nanoscaled Si particles were mechanochemically coupled with approximately 3 nm thick oxide layer and n-carbon (nanoscaled carbon) crystallites to overcome silicon's inherent problems of poor electronic conductivity and severe volume change during lithiation and delithiation cycling. The oxide layer of SiO _x was chemically formed via a controlled oxygen environment during the process; meanwhile, the n-carbon crystallites were obtained by mechanical fragmentation from ?70 ?m sized multilayered graphene powders with a low degree of agglomeration. The Si-based composite anode, processed by the above-mentioned mechanochemical coupling, maintained a superior discharge capacity of 1767 mA h/g through 100 cycles with a Coulombic efficiency exceeding 98% at a current density of 100 mA/g. According to our current study, the coupling of the Si particles with oxide layer and n-carbon crystallites was found to be a significantly efficient way to prevent the performance degradation of the Si-based anode.

SUBMITTER: Yang HW 

PROVIDER: S-EPMC6641641 | biostudies-literature | 2017 Jul

REPOSITORIES: biostudies-literature