Investigating fundamental electrochemical capacitor processes

Camera flashes, electric vehicle acceleration and many other consumer applications require high power, and this power can most easily be provided by electrochemical capacitors (ECs) - charge storage systems similar to batteries. ECs require very little maintenance and can be cycled millions of times before they need replacement. Thus, they are ideal for use with alternative energy sources (e.g., solar panels or windmills) and in remote locations. Unfortunately, the charge stored on an EC disappears over time through "self-discharge" and this self-discharge means that a few days after you charged the EC, all of the charge is lost - even if the EC has not been used. In order to stop this self-discharge from happening, and allow the EC to hold the charge longer, we need to find out what reactions are happening in the EC to steal the charge, and our research will identify these reactions. As well, the EC electrodes (the solid masses where the charge is stored) contain long, curved holes, called pores. It is believed that the shape of these pores affects how much charge can be stored (which impacts how long the EC can power a device before it needs to be recharged) and how fast the charge can be added/removed (which impacts the power available to the device, e.g., the brightness of the camera flash). We are interested in determining which pore shape allows us to store the most charge and access this charge the fastest. Additionally, we will design and study new types of EC electrode where a material that stores lots of charge is placed on different parts of an electrode that gives a very high rate of charge removal. Given present economic (fuel prices) and societal (environmental movement) factors, the field of energy storage is expected to grow and this research program will be significant in the quest to produce ECs with high power and energy capabilities - a boon to our current and future energy needs. The personnel trained via this grant will be in an ideal position to join Canada's energy sector, and facilitate in the development of Canada as a world-leader in electrochemical capacitor research and commercialisation.