title: Biotemplating pores with size and shape diversity for Li-oxygen Battery Cathodes.
abstract: Synthetic porogens provide an easy way to create porous structures, but their usage is limited due to synthetic difficulties, process complexities and prohibitive costs. Here we investigate the use of bacteria, sustainable and naturally abundant materials, as a pore template. The bacteria require no chemical synthesis, come in variable sizes and shapes, degrade easier and are approximately a million times cheaper than conventional porogens. We fabricate free standing porous multiwalled carbon nanotube (MWCNT) films using cultured, harmless bacteria as porogens, and demonstrate substantial Li-oxygen battery performance improvement by porosity control. Pore volume as well as shape in the cathodes were easily tuned to improve oxygen evolution efficiency by 30% and double the full discharge capacity in repeated cycles compared to the compact MWCNT electrode films. The interconnected pores produced by the templates greatly improve the accessibility of reactants allowing the achievement of 4,942 W/kg (8,649 Wh/kg) at 2 A/ge(1.7 mA/cm2).
authors.affiliation: IBM Almaden Research Center, San Jose, CA 95120, USA. dahyun@alum.mit.edu.
authors.forename: Dahyun
authors.initials: D
authors.lastname: Oh
authors.affiliation: ASELSAN Inc. - Microelectronics, Guidance and Electro-Optics Business Sector, Ankara, 06750, Turkey.
authors.forename: Cagla
authors.initials: C
authors.lastname: Ozgit-Akgun
authors.affiliation: ASELSAN Inc. - Microelectronics, Guidance and Electro-Optics Business Sector, Ankara, 06750, Turkey.
authors.forename: Esin
authors.initials: E
authors.lastname: Akca
authors.affiliation: IBM Almaden Research Center, San Jose, CA 95120, USA.
authors.forename: Leslie E
authors.initials: LE
authors.lastname: Thompson
authors.affiliation: IBM Almaden Research Center, San Jose, CA 95120, USA.|Chemistry Department, Minnesota State University Moorhead, Moorhead, MN 56563, USA.|Present address: Department of Bioengineering, Stanford University, Stanford, CA 94305-4125, USA.
authors.forename: Loza F
authors.initials: LF
authors.lastname: Tadesse
authors.affiliation: IBM Almaden Research Center, San Jose, CA 95120, USA.
authors.forename: Ho-Cheol
authors.initials: HC
authors.lastname: Kim
authors.affiliation: ASELSAN Inc. - Microelectronics, Guidance and Electro-Optics Business Sector, Ankara, 06750, Turkey.
authors.forename: Gökhan
authors.initials: G
authors.lastname: Demirci
authors.affiliation: IBM Almaden Research Center, San Jose, CA 95120, USA. rdmiller@us.ibm.com.
authors.forename: Robert D
authors.initials: RD
authors.lastname: Miller
authors.affiliation: IBM Almaden Research Center, San Jose, CA 95120, USA. hmaune@us.ibm.com.
authors.forename: Hareem
authors.initials: H
authors.lastname: Maune