Engineering pore ratio in hierarchical porous carbons towards high-rate and large-volumetric performances

Research output: Contribution to journalResearch articleContributedpeer-review

Contributors

  • Fei Xu - , Northwestern Polytechnical University Xian, TUD Dresden University of Technology (Author)
  • Haojie Han - , Northwestern Polytechnical University Xian (Author)
  • Baichuan Ding - , Northwestern Polytechnical University Xian (Author)
  • Yuqian Qiu - , Northwestern Polytechnical University Xian (Author)
  • En Zhang - , Chair of Inorganic Chemistry I (Author)
  • Hejun Li - , Northwestern Polytechnical University Xian (Author)
  • Stefan Kaskel - , Chair of Inorganic Chemistry I (Author)

Abstract

Hierarchical yet densely packed porous carbon electrodes are vital for achieving high-performance capacitive energy storage. However, hierarchical porous carbons (HPCs) suffer from a trade-off in terms of meso- and macroporosity ratio related to the pore size dependent diffusive ion mobility versus the material density dominating the volumetric performance. Here we report an interesting insight into a balanced effect of meso- and macroporosity ratio and the material density with a practical high mass loading by designing HPCs with controlled meso- and macroporosity ratio. This is achieved via a hypercrosslinking strategy of polystyrene without the assistant of any templates or activation. It is found that ion transport rates increase along with increasing the meso- and macropore content to 26% and then gradually level off even further increasing the amount to 73%. An appropriate meso- and macropore content without sacrificing the ion diffusivity is beneficial for achieving effective material densities up to 0.76 g cm−3, leading to superior volumetric capacitances, as compared with those showing either lower or higher meso- and macropore content. This study clearly highlights the need for fine-tuning the pore ratios at different scales in hierarchical structures to achieve high-performance applications for practical applications.

Details

Original languageEnglish
Pages (from-to)205-210
Number of pages6
JournalMicroporous and mesoporous materials
Volume282
Publication statusPublished - 26 Mar 2019
Peer-reviewedYes

Keywords

Keywords

  • Hierarchical porous carbons, Hypercrosslinked polystyrene, Ion transport rate, Supercapacitors, Volumetric capacitance