title: Graphene oxide-immobilized NH₂-terminated silicon nanoparticles by cross-linked interactions for highly stable silicon negative electrodes.
abstract: There is a great interest in the utilization of silicon-based anodes for lithium-ion batteries. However, its poor cycling stability, which is caused by a dramatic volume change during lithium-ion intercalation, and intrinsic low electric conductivity hamper its industrial applications. A facile strategy is reported here to fabricate graphene oxide-immobilized NH2-terminated silicon nanoparticles (NPs) negative electrode (Si@NH2/GO) directed by hydrogen bonding and cross-linked interactions to enhance the capacity retention of the anode. The NH2-modified Si NPs first form strong hydrogen bonds and covalent bonds with GO. The Si@NH2/GO composite further forms hydrogen bonds and covalent bonds with sodium alginate, which acts as a binder, to yield a stable composite negative electrode. These two chemical cross-linked/hydrogen bonding interactions-one between NH2-modified Si NPs and GO, and another between the GO and sodium alginate-along with highly mechanically flexible graphene oxide, produced a robust network in the negative electrode system to stabilize the electrode during discharge and charge cycles. The as-prepared Si@NH2/GO electrode exhibits an outstanding capacity retention capability and good rate performance, delivering a reversible capacity of 1000 mAh g(-1) after 400 cycles at a current of 420 mA g(-1) with almost 100% capacity retention. The results indicated the importance of system-level strategy for fabricating stable electrodes with improved electrochemical performance.
authors.affiliation: Fok Ying Tung Graduate School, The Hong Kong University of Science and Technology , Clear Water Bay, Kowloon, Hong Kong, China.
authors.forename: Cheng
authors.initials: C
authors.lastname: Sun
authors.forename: Yuanfu
authors.initials: Y
authors.lastname: Deng
authors.forename: Lina
authors.initials: L
authors.lastname: Wan
authors.forename: Xusong
authors.initials: X
authors.lastname: Qin
authors.forename: Guohua
authors.initials: G
authors.lastname: Chen