A phone battery typically takes at least 30 min to 1 hour to charge completely. Imagine being able to charge the same within a few minutes. Supercapacitors are one of the key devices for energy-storage applications which possess much better power handling capabilities than batteries, i.e. they can be charged much faster than batteries, and can store much higher amounts of energy than conventional capacitors. To achieve a high performance supercapacitor, we need materials with high surface area, along with high material density and superior conductivity. But unfortunately, surface area and material density are inversely proportional characteristics of a material. In particular, porous materials have high surface area, but lack a large material density and hence exhibit a poor electrical conductivity.
In our lab, we have developed a bottom-up approach to synthesise novel nano-structures, leading us to a unique, controlled spatial arrangement of nano-particles, which in turn has provided us the key to achieving the highest volumetric surface area reported so far for carbon. This approach enabled us to create carbon foams to target very specific applications and tailor material properties accordingly. For example, these carbon foams as ultra-thick electrodes for supercapacitor applications resulted in very high energy density and high power devices, thanks to the hierarchical structure of the pores made by nano-particles of specific aspect-ratios. Also, in the electrode developed for Si-based battery anodes, by introducing a novel elastic material, we have obtained excellent structural stability under high lithiation rate.
We have been awarded S$ 10 million from the Singapore National Research Foundation (NRF) for the above projects (List of awarded NRF CRP projects). A new lab is under operation for this at S12-01-08, Department of Physics, National University of Singapore. Simultaneously, we are in collaboration with a key industry player in supercapacitors, muRata Manufacturing Co. Ltd.