By Dr Peter Harrop, Chairman, IDTechEx
One way that supercapacitors are developing faster than batteries is in the choice of format, from transfer printable ones for mobile phones to load-bearing structural components and smart skin for vehicles. In the European Union Powerweave project, supercapacitors not batteries have been chosen as the energy storage layers on the fibre being developed for self-powered wearable electronics from bandages to dresses. The reason is that they have high power density, long lifetime and low internal resistance, and they can be constructed from commonly available, low cost materials, so they are potentially low cost.
In the recently updated IDTechEx report “Supercapacitor/ Ultracapacitor Interviews, Strategies, Road Map 2014-2024” www.idtechex.com/superApps, the IDTechEx roadmap has graphene active electrodes promising up to 200 Wh/kg, well ahead of today’s lithium-ion batteries. The replacement of lithium-ion batteries with supercapacitors, that occasionally happens today despite them having one tenth of the energy density, could become a flood. 120 Hz versions are planned for replacing electrolytic capacitors in power supplies, reducing size and increasing reliability and life. Supercapacitors and their derivatives supercabatteries (asymmetric electrochemical double layer capacitors AEDLC), particularly the lithium-ion capacitor versions, are rapidly widening in application as a result of all this.
The European electric vehicle industry is weakened by having to import lithium-ion batteries from Japan, China and Korea to get the best price/performance for mass markets. However, Europe will also stay weak in supercapacitors, its investors failing to see that supercapacitors are increasingly key enabling components for EVs and other applications. They are concentrating too much on fighting yesterday’s battles. There are a few exceptions such as Maxwell Technologies who derived its largest business from putting them across the traction batteries in pure electric buses in China. WIMA of Germany sold huge water-cooled energy harvesting supercapacitors for Komatsu and other construction vehicles in Japan but Europe continues to be a net importer of supercapacitors.
