title: Site-specific carbon deposition for hierarchically ordered core/shell-structured graphitic carbon with remarkable electrochemical performance.
abstract: A fascinating core-shell-structured graphitic carbon material composed of ordered microporous core and uniform mesoporous shell is fabricated for the first time through a site-specific chemical vapor deposition process by using a nanozeolite@mesostructured silica composite molecular sieve as the template. The mesostructure-directing agent cetyltrimethylammonium bromide in the shell of the template can be either burned off or carbonized so that it is successfully utilized as a pore switch to turn the shell of the template "on" or "off" to allow selective carbon deposition. The preferred carbon deposition process can be performed only in the inner microporous zeolite cores or just within the outer mesoporous shells, resulting in a zeolite-like ordered microporous carbon or a hollow mesoporous carbon. Full carbon deposition in the template leads to the new core-shell-structured microporous@mesoporous carbon with a nanographene-constructed framework for fast electron transport, a microporous nanocore with large surface area for high-capacity storage of lithium ions, a mesoporous shell with highly opened mesopores as a transport layer for lithium ions and electron channels to access inner cores. The ordered micropores are protected by the mesoporous shell, avoiding pore blockage as the formation of solid electrolyte interphase layers. Such a unique core-shell-structured microporous@mesoporous carbon material represents a newly established lithium ion storage model, demonstrating high reversible energy storage, excellent rate capability, and long cyclic stability.
authors.affiliation: Department of Chemistry, Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Laboratory of Advanced Materials, Fudan University, Shanghai 200433 (PR China).
authors.forename: Yingying
authors.initials: Y
authors.lastname: Lv
authors.forename: Zhangxiong
authors.initials: Z
authors.lastname: Wu
authors.forename: Xufang
authors.initials: X
authors.lastname: Qian
authors.forename: Yin
authors.initials: Y
authors.lastname: Fang
authors.forename: Dan
authors.initials: D
authors.lastname: Feng
authors.forename: Yongyao
authors.initials: Y
authors.lastname: Xia
authors.forename: Bo
authors.initials: B
authors.lastname: Tu
authors.forename: Dongyuan
authors.initials: D
authors.lastname: Zhao
mesh_terms: D000077286:Cetrimonium; D002593:Cetrimonium Compounds / Q000737:chemistry; D004563:Electrochemistry; D004738:Engineering; D006108:Graphite / Q000737:chemistry*; D016062:Porosity; D012822:Silicon Dioxide / Q000737:chemistry
chemical_list: D002593:Cetrimonium Compounds; D012822:Silicon Dioxide; D006108:Graphite; D000077286:Cetrimonium
keywords: chemical vapor deposition; lithium ion batteries; mesoporous materials; nanostructures; zeolites