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Three-Dimensional Nanoelectrode by Metal Nanowire Nonwoven Clothes
journal contribution
posted on 2014-04-09, 00:00 authored by Makoto Kawamori, Takahiro Asai, Yoshimasa Shirai, Shunsuke Yagi, Masatsugu Oishi, Tetsu Ichitsubo, Eiichiro MatsubaraMetal
nanowire nonwoven cloth (MNNC) is a metal sheet that has
resulted from intertwined metal nanowires 100 nm in diameter with
several dozen micrometers of length. Thus, it is a new metallic material
having both a flexibility of the metal sheet and a large specific
surface area of the nanowires. As an application that utilizes these
properties, we propose a high-cyclability electrode for Li storage
batteries, in which an active material is deposited or coated on MNNC.
The proposed electrode can work without any binders, conductive additives,
and current collectors, which might largely improve a practical gravimetric
energy density. Huge electrode surfaces provide efficient ion/electron
transports, and sufficient interspaces between the respective nanowires
accommodate large volume expansions of the active material. To demonstrate
these advantages, we have fabricated a NiO-covered nickel nanowire
nonwoven cloth (NNNC) by electroless deposition under a magnetic field
and annealing in air. The adequately annealed NNNC was shown to be
an excellent conversion-type electrode that exhibits a quite high
cyclability, 500 mAh/g at 1 C after 300 cycles, compared to that of
a composite electrode consisting of NiO nanoparticles. Thus, the present
design concept will contribute to a game-changing technology in future
lithium ion battery (LIB) electrodes.