Supercapacitors -jostling for leadership

Dr Peter Harrop, Chairman, IDTechEx



Supercapacitor market leader Maxwell Technologies has faltered temporarily due to phasing of demand for supercapacitors on Chinese hybrid buses. One of the most formidable innovators it now sells large stacks for grid management and for energy harvesting in large construction vehicles. The recent IDTechEx Supercapacitors event in Santa Clara, California taught us more.

Supercapacitor companies have been bought or closed recently but new manufacturers are encouraged by 100% growth rate of Ioxus and much larger growth of Nippon Chemicon. IDTechEx forecasts 30% growth for ten years. The growing number of manufacturers, currently at 85, are all getting some business. There is a clear roadmap of new applications kicking in. See the IDTechEx report, Supercapacitor / Ultracapacitor Interviews, Strategies, Road Map 2014-2025. Professor Burke of the University of California Davis argued that the adoption of supercapacitors by Honda and Mazda in conventional and hybrid vehicles will force other manufacturers to adopt a more optimal, supercapacitor-centric approach to design, improving both reliability and performance.

He argued that the difference in energy density between the lithium-ion batteries currently favoured and supercapacitors is much less than portrayed because powertrain designers only use 5-10% of the battery capacity in a hybrid to get the fast charge/ discharge. They like a lot of energy storage in reserve but this is not optimal. Indeed, having converted his own hybrid car and carried out extensive research Burke finds that even smaller supercapacitors suffice in hybrids. The huge market potential is given in the IDTechEx report, Electric Vehicle Forecasts, Trends and Opportunities 2015-2025.

Many car manufacturers are now assessing supercapacitors for their next hybrids, following the practice of Chinese bus manufacturers, MAN buses in Germany, the Toyota Formula One racer, the Yaris concept car and other hybrid electric vehicles in adopting supercapacitors in place of lithium-ion batteries. Add the trend to an increasing minority of stop-start and energy harvesting alternator systems on conventional cars adopting supercapacitors so they operate at low temperature and with the toughest duty cycles. Professor Burke felt that there will one day be another jump in adoption of supercapacitors in electric vehicles but, for him, "It has been a long wait".