Metal-Organic-Framework-Derived N-Doped Hierarchically Porous Carbon Polyhedrons Anchored on Crumpled Graphene Balls as Efficient Selenium Hosts for High-Performance Lithium-Selenium Batteries

Seung Keun Park, Jin Sung Park, Yun Chan Kang

Research output: Contribution to journalArticle

25 Citations (Scopus)

Abstract

Developing carbon scaffolds showing rational pore structures as cathode hosts is essential for achieving superior electrochemical performances of lithium-selenium (Li-Se) batteries. Hierarchically porous N-doped carbon polyhedrons anchored on crumpled graphene balls (NPC/CGBs) are synthesized by carbonizing a zeolitic imidazolate framework-8 (ZIF-8)/CGB composite precursor, producing an unprecedented effective host matrix for high-performance Li-Se batteries. Mesoporous CGBs obtained by one-pot spray pyrolysis are used as a highly conductive matrix for uniform polyhedral ZIF-8 growth. During carbonization, ZIF-8 polyhedrons on mesoporous CGBs are converted into N-doped carbon polyhedrons showing abundant micropores, forming a high-surface-area, high-pore-volume hierarchically porous NPC/CGB composite whose small unique pores effectively confine Se during melt diffusion, thereby providing conductive electron pathways. Thus, the integrated NPC/CGB-Se composite ensures high Se utilization originating from complete electrochemical reactions between Se and Li ions. The NPC/CGB-Se composite cathode exhibits high discharge capacities (998 and 462 mA h g-1 at the 1st and 1000th cycles, respectively, at a 0.5 C current density), good capacity retention (68%, calculated from the 3rd cycle), and excellent rate capability. A discharge capacity of 409 mA h g-1 is achieved even at an extremely high (15.0 C) current density.

Original languageEnglish
Pages (from-to)16531-16540
Number of pages10
JournalACS Applied Materials and Interfaces
Volume10
Issue number19
DOIs
Publication statusPublished - 2018 May 16

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Keywords

  • crumpled graphene balls
  • hierarchically porous materials
  • lithium-selenium batteries
  • metal-organic frameworks
  • spray pyrolysis

ASJC Scopus subject areas

  • Materials Science(all)

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