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This content will become publicly available on May 23, 2018

Title: Unrivaled combination of surface area and pore volume in micelle-templated carbon for supercapacitor energy storage

Here, we created Immense Surface Area Carbons (ISACs) by a novel heat treatment that stabilized the micelle structure in a biological based precursor prior to high temperature combined activation – pyrolysis. While displaying a morphology akin to that of commercial activated carbon, ISACs contain an unparalleled combination of electrochemically active surface area and pore volume (up to 4051 m 2 g –1, total pore volume 2.60 cm 3 g –1, 76% small mesopores). The carbons also possess the benefit of being quite pure (combined O and N: 2.6–4.1 at%), thus allowing for a capacitive response that is primarily EDLC. Tested at commercial mass loadings (~10 mg cm –2) ISACs demonstrate exceptional specific capacitance values throughout the entire relevant current density regime, with superior rate capability primarily due to the large fraction of mesopores. In the optimized ISAC, the specific capacitance ( C g) is 540 F g –1 at 0.2 A g –1, 409 F g –1 at 1 A g –1 and 226 F g –1 at a very high current density of 300 A g –1 (~0.15 second charge time). At intermediate and high currents, such capacitance values have not been previously reported for any carbon. Tested withmore » a stable 1.8 V window in a 1 M Li 2SO 4 electrolyte, a symmetric supercapacitor cell yields a flat energy–power profile that is fully competitive with those of organic electrolyte systems: 29 W h kg –1 at 442 W kg –1 and 17 W h kg –1 at 3940 W kg –1. The cyclability of symmetric ISAC cells is also exceptional due to the minimization of faradaic reactions on the carbon surface, with 80% capacitance retention over 100 000 cycles in 1 M Li 2SO 4 and 75 000 cycles in 6 M KOH.« less
Authors:
ORCiD logo [1] ;  [2] ;  [2] ;  [2] ;  [2] ;  [2] ;  [2] ;  [1] ;  [1] ;  [3] ; ORCiD logo [1] ;  [2] ;  [1]
  1. Clarkson Univ., Potsdam, NY (United States)
  2. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
  3. State Univ. of New York, Binghamton, NY (United States)
Publication Date:
Grant/Contract Number:
AC05-00OR22725
Type:
Accepted Manuscript
Journal Name:
Journal of Materials Chemistry. A
Additional Journal Information:
Journal Volume: 5; Journal Issue: 26; Journal ID: ISSN 2050-7488
Publisher:
Royal Society of Chemistry
Research Org:
Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States). Center for Nanophase Materials Sciences (CNMS); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Spallation Neutron Source (SNS)
Sponsoring Org:
USDOE Laboratory Directed Research and Development (LDRD) Program
Country of Publication:
United States
Language:
English
Subject:
25 ENERGY STORAGE; 36 MATERIALS SCIENCE; energy storage; high power; aqueous battery; lithium ion battery; sodium ion battery; activated carbon; graphite; graphene; nanotube; two dimensional; sulfur; phosphorous; doped carbon; heteroatom
OSTI Identifier:
1366417