Core-shell Si@c-PAN particles deposited on graphite as promising anode for lithium-ion batteries. (20th February 2019)

• Record Type: Journal Article
• Authors: Nguyen, Quoc Hai; Kim, Il Tae; Hur, Jaehyun
• Is Part Of: Electrochimica acta. Volume 297(2019)
• Page Start: 355
• Page End: 364
• Publication Date: 2019-02-20
• Subjects: Silicon -- c-PAN -- Core-shell -- Post-annealing anode -- Lithium-ion battery; Electrochemistry -- Periodicals; Electrochemistry, Industrial -- Periodicals; 541.37
• DOI: 10.1016/j.electacta.2018.12.005
• Languages: English
• ISSNs: 0013-4686

Abstract

Abstract: In this study, a three-dimensional silicon@cyclized-polyacrylonitrile@graphite (Si@c-PAN@G) nanocomposite structure, consisting of core-shell Si(core)@c-PAN(shell) deposited on a graphite matrix, is fabricated using simple high-energy ball milling (HEBM) followed by heat-treatment. As an anode material for lithium-ion batteries, which is a thin layer (∼2.5 nm) of c-PAN coated on Si nanoparticles, it efficiently accommodates a large volume change of Si particles, inhibiting the pulverization and maintaining an appropriate contact with the current collector. At the same time, the graphite functions as a matrix for Si@c-PAN nanoparticles, which not only prevents the agglomeration of Si@c-PAN particles, but also provides an efficient electron transport during cycling, resulting in an outstanding electrochemical performance for Si@c-PAN@G. This novel electrode exhibits an excellent initial capacity (∼1580 mAh g −1 at 0.2 A g −1 with a coulombic efficiency of 79%), highly stable cyclic performances (1422 mAh g −1 at 0.2 A g −1 with capacity retention of 90% after 50 cycles and 1071 mAh g −1 at 1 A g −1 with capacity retention of 85% after 100 cycles), high rate capability (capacity retention of ∼95% at 3.0 A g −1 compared with the capacity at 0.2 A g −1 ), and low charge transfer resistance (<30 Ω) compared with other Si-based composite electrodes. To achieve these, a new post-annealing strategy for electrode film, the appropriate binder and the optimum weight ratio between c-PAN and graphite are further investigated. Graphical abstract: The core-shell structure of Si(core)@c-PAN(shell) particles deposited on a graphite matrix is fabricated using simple high-energy ball milling (HEBM) followed by heat-treatment, as a high performance anode material for lithium-ion batteries. Image 1 Highlights: Si@c-PAN@G nanocomposite was developed by HEMM for high-performance anodes in LIBs. Si and c-PAN form core-shell structure due to their high affinity. C-PAN and graphite effectively function as buffering matrices for Si anode. Excellent electrochemical performances of Si@c-PAN@G were demonstrated. Conditions of film annealing, binder, and constituent ratio were investigated.