title: Electrochemically tunable thermal conductivity of lithium cobalt oxide.
abstract: Using time-domain thermoreflectance, the thermal conductivity and elastic properties of a sputter deposited LiCoO2 film, a common lithium-ion cathode material, are measured as a function of the degree of lithiation. Here we report that via in situ measurements during cycling, the thermal conductivity of a LiCoO2 cathode reversibly decreases from ~5.4 to 3.7 W m(-1) K(-1), and its elastic modulus decreases from 325 to 225 GPa, as it is delithiated from Li1.0CoO2 to Li0.6CoO2. The dependence of the thermal conductivity on lithiation appears correlated with the lithiation-dependent phase behaviour. The oxidation-state-dependent thermal conductivity of electrolytically active transition metal oxides provides opportunities for dynamic control of thermal conductivity and is important to understand for thermal management in electrochemical energy storage devices.
authors.affiliation: Department of Materials Science and Engineering, Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.
authors.forename: Jiung
authors.initials: J
authors.lastname: Cho
authors.affiliation: Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, North Carolina 27695, USA.
authors.forename: Mark D
authors.initials: MD
authors.lastname: Losego
authors.affiliation: Department of Materials Science and Engineering, Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.
authors.forename: Hui Gang
authors.initials: HG
authors.lastname: Zhang
authors.affiliation: Department of Materials Science and Engineering, Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.
authors.forename: Honggyu
authors.initials: H
authors.lastname: Kim
authors.affiliation: Department of Materials Science and Engineering, Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.
authors.forename: Jianmin
authors.initials: J
authors.lastname: Zuo
authors.affiliation: Department of Materials Science and Engineering, Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.
authors.forename: Ivan
authors.initials: I
authors.lastname: Petrov
authors.affiliation: 1] Department of Materials Science and Engineering, Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA [2] International Institute for Carbon Neutral Energy Research (WPI-I2CNER), Kyushu University, 744 Moto-oka, Fukuoka 819-0395, Japan.
authors.forename: David G
authors.initials: DG
authors.lastname: Cahill
authors.affiliation: Department of Materials Science and Engineering, Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.
authors.forename: Paul V
authors.initials: PV
authors.lastname: Braun