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for the alternative energy fields. Synergistically, this comes at a time when the synthetic ability to make and control various modular hybrid organic/inorganic materials for advanced functionalities is drastically improving. The types of applications
that have been studied thus far include supercapacitors, batteries, fuel cells, and
solar cells, to name the major ones to be discussed here, alongside other devices
such as electrical gas sensors. The requirements have become such that more convenience and mechanical flexibility in the devices, along with greater energy capacity
per unit mass or unit volume, with the ability to rapidly charge and discharge for
high power operation is needed. Moreover, the goal is to gain more specificity with
little need for maintenance, and perhaps most importantly, long-lasting and safe
technology.
Without the advent of advanced energy solutions, lightweight, modern electronics would not be possible. For example, compare a heavy lead-acid battery to the
lithium ion batteries used in laptops today. The advancements in and miniaturization of technology and electronics need to be accompanied by similar development
of their power sources. Although major improvements have been made, and are
continuously advancing, most current technology is based on liquid organic electrolytes, which have considerable drawbacks, such as potential for leakage, flammability, and narrow temperature ranges of operation. Therefore, solid or elastomeric
organic materials are sought after, having the advantage of being generally lightweight, processable, and flexible, with relative ease of manufacturing in many cases.
In addition, there is an improvement in robustness and safety when compared to
liquids.
At the heart of all electrochemical devices is the electrolyte, as depicted in simplified schematics in Fig. 1. Despite differences in construction, they fundamentally
utilize connected electrodes separated by an electrically insulating membrane to
force the electrons to move through the wire and therefore generate electrical work.
Movement of electrons needs to be balanced by the movement of ions between the
electrodes. Electrolytes conduct charge by an accompanying movement of ions, and
in these devices, they are chosen for their ionic transport capabilities. Electrical
work is done directionally, and ion movement in an organized, directional fashion
may also be of use to minimize randomness and self-diffusion of ions. Because of
the inherent limitations of liquid-phase materials (including both aqueous and
organic solvents), these fundamentally do not meet the demands of future devices
and require considerable improvement. Ionic liquids can provide an enhancement in
terms of conductivity and thermal stability with a much lower vapor pressure at
standard conditions, but still do not solve all issues. So, many have shifted their
attention toward solid solutions. A common theme presents in the development of
these technologies, and each goes through a similar maturation process. The first
devices are made with liquid electrolytes, which are simpler and effective (such as
sulfuric acid in lead-acid batteries). Once optimization reaches a certain point, ionic
liquids are utilized to allow for more robustness and wider operational capability.
Finally, the solid state becomes important, even crucial, for first generation commercial devices.
C. A. Bauer
for the alternative energy fields. Synergistically, this comes at a time when the synthetic ability to make and control various modular hybrid organic/inorganic materials for advanced functionalities is drastically improving. The types of applications
that have been studied thus far include supercapacitors, batteries, fuel cells, and
solar cells, to name the major ones to be discussed here, alongside other devices
such as electrical gas sensors. The requirements have become such that more convenience and mechanical flexibility in the devices, along with greater energy capacity
per unit mass or unit volume, with the ability to rapidly charge and discharge for
high power operation is needed. Moreover, the goal is to gain more specificity with
little need for maintenance, and perhaps most importantly, long-lasting and safe
technology.
Without the advent of advanced energy solutions, lightweight, modern electronics would not be possible. For example, compare a heavy lead-acid battery to the
lithium ion batteries used in laptops today. The advancements in and miniaturization of technology and electronics need to be accompanied by similar development
of their power sources. Although major improvements have been made, and are
continuously advancing, most current technology is based on liquid organic electrolytes, which have considerable drawbacks, such as potential for leakage, flammability, and narrow temperature ranges of operation. Therefore, solid or elastomeric
organic materials are sought after, having the advantage of being generally lightweight, processable, and flexible, with relative ease of manufacturing in many cases.
In addition, there is an improvement in robustness and safety when compared to
liquids.
At the heart of all electrochemical devices is the electrolyte, as depicted in simplified schematics in Fig. 1. Despite differences in construction, they fundamentally
utilize connected electrodes separated by an electrically insulating membrane to
force the electrons to move through the wire and therefore generate electrical work.
Movement of electrons needs to be balanced by the movement of ions between the
electrodes. Electrolytes conduct charge by an accompanying movement of ions, and
in these devices, they are chosen for their ionic transport capabilities. Electrical
work is done directionally, and ion movement in an organized, directional fashion
may also be of use to minimize randomness and self-diffusion of ions. Because of
the inherent limitations of liquid-phase materials (including both aqueous and
organic solvents), these fundamentally do not meet the demands of future devices
and require considerable improvement. Ionic liquids can provide an enhancement in
terms of conductivity and thermal stability with a much lower vapor pressure at
standard conditions, but still do not solve all issues. So, many have shifted their
attention toward solid solutions. A common theme presents in the development of
these technologies, and each goes through a similar maturation process. The first
devices are made with liquid electrolytes, which are simpler and effective (such as
sulfuric acid in lead-acid batteries). Once optimization reaches a certain point, ionic
liquids are utilized to allow for more robustness and wider operational capability.
Finally, the solid state becomes important, even crucial, for first generation commercial devices.
C. A. Bauer