Table Of ContentApplications of Electroactive Polymers
Applications of Electroactive
Polymers
Edited by
Bruno Scrosati
Chemistry Department
University of Rome 'La Sapienza'
Italy
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SPRINGER-SCIENCE+BUSINESS MEDIA, B.V
First edition 1993
© 1993 Springer Science+Business Media Dordrecht
OriginalIy published by Chapman & HalI in 1993
Softcover reprint ofthe hardcover lst edition 1993
ISBN 978-94-010-4684-8 ISBN 978-94-011-1568-1 (eBook)
DOI 10.1007/978-94-011-1568-1
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Contents
List of contributors Vll
Preface xi
1 Electrical and electrochemical properties of ion conducting
polymers 1
Roger G. Linford
2 Electrical and electrochemical properties of electronically
conducting polymers 29
William H. Smyrl and Mary Lien
3 Highly conductive polymer electrolytes 75
K.M. Abraham
4 Solvation mechanisms in low molecular weight polyethers 113
Michael Mendolia, H. Cai and Gregory C. Farrington
5 Lithium batteries with polymer electrodes 150
Nobuhiro Furukawa and Koji Nishio
6 Lithium polymer batteries 182
Bruno Serosati and Robin J. Neat
7 Electrochromic devices 223
Marina M astragostino
8 Laminated electrochromic displays and windows 250
Bruno Serosati
vi Contents
9 Functionalized conducting polymer membranes/films 283
Takeo Shimidzu
10 Electroactive polymers in chemical sensors 310
Mira J osowicz and J if{ J anata
Index 345
Contributors
K.M. Abraham
EIC Laboratories Inc.,
111 Downey Street,
Norwood,
Massachusetts
02062,
USA
H. Cai
Department of Materials Science and Engineering,
University of Pennsylvania,
3231 Walnut Street,
Philadelphia,
PA 19104,
USA
Gregory C. Farrington
Department of Materials Science and Engineering,
University of Pennsylvania,
3231 Walnut Street,
Philadelphia,
PA 19104,
USA
Nobuhiro Furukawa
Sanyo Electric Co. Ltd,
Functional Materials Research Center,
1-18-13 Hashiridiani,
Hirakata Osaka,
Japan
viii Contributors
Jiti Janata
Molecular Science Research Center,
Pacific Northwest Laboratory,
Richland,
WA 99352,
USA
Mira J osowicz
Institut fUr Physik,
FakulHit fUr Elektrotechnik,
Universitat der Bundeswehr
Munchen,
Dw-8014
Neubiberg,
Germany
Mary Lien
University of Minnesota,
Corrosion Research Center,
Department of Chemical Engineering and Materials Science,
Minneapolis,
MN 55455
USA
Roger G. Linford
Department of Chemistry,
De Montfort University,
The Gateway,
Leicester,
LEI9BH,
UK
Marina Mastragostino
Dipartimento di Chimica,
'G. Ciamician',
Universita di Bologna,
Bologna,
Italy
Michael Mendolia
Department of Materials Science and Engineering,
University of Pennsylvania,
3231 Walnut Street,
Philadelphia,
PA 19104,
USA
Contributors ix
Robin J. Neat
AEA Industrial Technology,
Harwell Laboratory,
Oxfordshire,
OXll ORA,
UK
Koji Nishio
Sanyo Electric Co. Ltd,
Functional Materials Research Center,
1-18-13 Hashiridiani,
Hirakata Osaka,
Japan
Bruno Scrosati
Dipartimento di Chimica,
Universita di Roma,
'La Sapienza',
00185, Rome,
Italy
Takeo Shimidzu
Division of Molecular Engineering,
Graduate School of Engineering,
Kyoto University,
Kyoto 606,
Japan
William H. Smyrl
University of Minnesota,
Corrosion Research Center,
Department of Chemical Engineering and Materials Science,
Minneapolis,
MN 55455,
USA
Preface
Electroactive polymers have been the object of increasing academic and
industrial interest and in the past ten to fifteen years substantial progress
has been achieved in the development and the characterization of this
important new class of conducting materials. These materials are usually
classified in two large groups, according to the mode of their electric
transport. One group includes polymers having transport almost exclusively
of the ionic type and they are often called 'polymer electrolytes' or, in a
broader way, 'polymer ionics'. The other group includes polymeric materials
where the transport mechanism is mainly electronic in nature and which are
commonly termed 'conducting polymers'.
Ionically conducting polymers or polymer ionics may be typically
described as polar macromolecular solids in which one or more of a wide
range of salts has been dissolved. The most classic example is the combina
tion of poly(ethylene oxide), PEO, and lithium salts, LiX. These PEO-LiX
polymer ionics were first described and proposed for applications just over
ten years ago. The practical relevance of these new materials was im
mediately recognized and in the course of a few years the field expanded
tremendously with the involvement of many academic and industrial lab
oratories. Following this diversified research activity, the ionic transport
mechanism in polymer ionics was soon established and this has led to the
development of new host polymers of various types, new salts and advanced
polymer architectures which have enabled room temperature conductivity
to be raised by several orders of magnitude.
In addition, the various types of polymer ionics can be easily fabricated
into flexible thin films with large surface areas where the ions are free to
move and can conduct electricity as in conventional liquid electrolytes. This
has opened the challenging possibility of replacing the difficult to handle,
often hazardous, liquid solutions by chemically inert, thin-layer membranes
for the fabrication of advanced electrochemical devices. Particularly relevant
in this respect has been the technological goal of replacing liquid electrolytes
in lithium, non-aqueous batteries by a thin film of a solid polymer electro
lyte which would act both as electrode separator and as a medium for ionic
xu Preface
transport. A number of commercial organizations in different countries
are now actively developing these revolutionary electrochemical power
sources.
Finally, polymer ionics are of key importance for the fabrication and
development of other exciting devices, such as laminated optical displays
and sensors, and it is generally realized that in technological terms these
ionically conducting polymers represent one of the most significant devel
opments in solid state electrochemistry.
The other group of materials, which covers the electronic conductors,
includes conjugated polymers whose electronic structure may be signif
icantly modified by electrochemical processes, sometimes designated as
doping processes, which involve the oxidation (removal of electrons) or
11:
the reduction (addition of electrons) of the polymer chain. Typical
11:
examples are the heterocyclic polymers, such as polypyrrole, poly thiophene
and their derivatives, and the polyanilines.
The discovery of the electronically conducting polymers also dates a
few years back when in the late seventies it was announced that the
conductivity of polyacetylene, an intrinsically insulating polymer, could be
raised by several orders of magnitude by redox processes run and con
trolled in electrochemical cells. Again the relevance of this discovery,
which opened the route for previously inconceivable devices, was soon
recognized. Indeed, conducting polymers, by deposition in thin-film con
figurations, may be used for the fabrication of novel types of electrodes
to be employed in advanced, rechargeable lithium batteries and of novel
types of organic conductors for the assembly of electronic components.
Furthermore, by appropriate functionalization, selected conducting poly
mers may be exploited as specific electrodes in highly selective sensors.
Finally, by taking advantage of the fact that upon doping the electronic
band evolution is accompanied by changes in the optical properties,
conducting polymers may find unique applications as optical switches in a
series of devices of importance for energy control in the automobile and the
building industries.
In analogy to the case of their parent ionically conducting group, these
electronic polymers have been the object of careful consideration during
the last decade. Significant progress has been achieved in their character
ization and today various industrial organizations are planning to launch
new polymer-based devices of large commercial value. Typical examples
are high volumetric energy density batteries for consumer electronics
and rear view mirrors for worldwide production in major automobile
industries.
The purpose of this book is to review and discuss the impact that both
groups of electroactive polymers may exert on the progress of modern
electrochemical technology. Although the attention is mainly focused on
applications, to facilitate full appreciation of the different topics treated in
