Sandpit: SUPERCAPACITORS FOR AN EFFECTIVE AND SUSTAINABLE POWER SYSTEM

An effective and sustainable power system is important and in many cases essential for many workers and individuals in today's world to power personal electronic and communication devices, to sustain mobile operations and the work of the mobile worker and businessman. Electric and hybrid transport vehicles are based on an effective and sustainable power system. In the majority of these cases, batteries are used for energy storage and, despite the considerable progress and developments in batteries, even the best Li-ion batteries are still heavy, bulky and cumbersome for medium and high power requirements. As a result, supercapacitors are proposed as an essential element of an effective and sustainable power system in which they may provide the peak load, extend battery life, easily provide sustainable high current and high power pulses. Furthermore, alternative power sources such as fuel cells and renewable energy sources are mostly of intermittent nature, hence, a supercapacitor is definitely needed for load levelling and smoothing in the power system. Future expectations of energy harvesting from such alternative sources cover a huge range of user systems, including devices and equipment used by individual people, transport vehicles, residence quarters, working quarters, even the electricity grid. Supercapacitors are generally high power density devices but they suffer from low energy densities. The highest performance supercapacitors are currently based on nanomaterials, given that increased electrode surface area improves the capacitance. The main forcus in this project is to develop novel supercapacitors with improved energy density (while maintaining very high levels of power density); in order to achieve this, it is proposed to develop novel fabrication techniques to increase the effective surface area and to consider the electrodes and electrolyte as a system rather than optimising the performance of the individual components, so that the best nanomaterials are developed that function at optimum performance in synergy, and also to investigate hybrid systems. Whereas the major task in this project will be the development of a high performance supercapacitor, there is also a workprogramme for a demonstrator of an effective and sustainable power system to be designed, assembled and tested, including the best supercapacitor, an intermittent energy source, such as a photovoltaic source, and a medium power consumption device operating at a simulated peak load profile. The aim of this part will be to demonstrate the effectiveness of the power system including the supercapacitor and its contribution to user's sustainability.

The supercapacitor in the proposed demo power system is expected to lead to an effective power management system for the current soldier that will improve the soldier trust in the system and the sustainability of both the power system and the soldier. The proposed tenfold increase in the performance of the novel supercapacitor from this project will make it at least equivalent to the current Li-ion battery in energy storage, while it will still have the excellent power characteristics of supercapacitor. This will make the novel supercapacitor an ideal energy storage device which could be used most conveniently in a power system with mixed power sources of intermittent nature, as it will have excellent features of rapid charge-discharge as supercapacitor and a novel large energy storage. Additionally, the new suparcapacitors are compliant, so they will fit body contours and will contribute to an ergonomic power system leading to an agile and sustainable soldier. Novel supercapacitors would be used in dual purpose applications, e.g. electric/fuel cell/hybrid cars, electronics, even National Grid. Due to diminishing non-renewable fuel resources, there is a drive worldwide for alternative renewable energy sources, many of them of intermittent nature. This means that supercapacitors will be essential for levelling off the load. Novel high performance supercapacitors that could be used in the dual role of capacitor and energy storage device will be of huge importance in future power systems.