9
Perspectives and Challenges
9.1 Introduction
Research and development efforts have been plentiful in recent years in
attempts to create new electrochemical supercapacitor (ES) component materials to improve the performance and commercial viability of this technology.
With incremental progress in the field of material development, considerable
technical advancements in ESs have been achieved in the past decade.
Two important material areas must be addressed: the ES electrode material, and the electrolyte material. Most of the research and development on
electrode materials development focuses on high capacitive materials such
as double-layer capacitive carbons, pseudocapacitive materials, and their
composites. Increasing the capacitances of electrode active materials is desirable because it will allow higher energy storage capabilities. However, in
developing these high capacitance materials, cost and cyclability challenges
must be considered.
Electrolyte materials (solvents and ionic species) are also important components of ES devices. Traditionally, aqueous electrolyte solutions were used
because they were nonhazardous and easy to handle. Aqueous electrolytes,
however, offer limited electrochemically stable operating potential windows
(up to ~1.0 V).
As the energy storage density is proportional to the square of the operating
voltage, using alternative electrolyte systems with significantly wider operating voltage stability windows can significantly improve the energy storage
capability of an ES device. On that front, organic and ionic liquid electrolytes
are under investigation. Most commercially available ES systems utilize
organic electrolytes. However, organic and ionic liquid electrolytes present
several material handling and technical challenges that must be overcome.
Despite marked improvements in recent years in ES electrode and electrolyte material areas, several challenges remain. In this chapter, the market challenges of ES development efforts will be first discussed, followed by
detailed discussions of the progress and technical challenges facing electrode and electrolyte material developments. In addition, the computational
tools that can be utilized to supplement material development efforts will
335
Perspectives and Challenges
9.1 Introduction
Research and development efforts have been plentiful in recent years in
attempts to create new electrochemical supercapacitor (ES) component materials to improve the performance and commercial viability of this technology.
With incremental progress in the field of material development, considerable
technical advancements in ESs have been achieved in the past decade.
Two important material areas must be addressed: the ES electrode material, and the electrolyte material. Most of the research and development on
electrode materials development focuses on high capacitive materials such
as double-layer capacitive carbons, pseudocapacitive materials, and their
composites. Increasing the capacitances of electrode active materials is desirable because it will allow higher energy storage capabilities. However, in
developing these high capacitance materials, cost and cyclability challenges
must be considered.
Electrolyte materials (solvents and ionic species) are also important components of ES devices. Traditionally, aqueous electrolyte solutions were used
because they were nonhazardous and easy to handle. Aqueous electrolytes,
however, offer limited electrochemically stable operating potential windows
(up to ~1.0 V).
As the energy storage density is proportional to the square of the operating
voltage, using alternative electrolyte systems with significantly wider operating voltage stability windows can significantly improve the energy storage
capability of an ES device. On that front, organic and ionic liquid electrolytes
are under investigation. Most commercially available ES systems utilize
organic electrolytes. However, organic and ionic liquid electrolytes present
several material handling and technical challenges that must be overcome.
Despite marked improvements in recent years in ES electrode and electrolyte material areas, several challenges remain. In this chapter, the market challenges of ES development efforts will be first discussed, followed by
detailed discussions of the progress and technical challenges facing electrode and electrolyte material developments. In addition, the computational
tools that can be utilized to supplement material development efforts will
335