4500Leading European manufacturer Skeleton Technologies has launched a new range of ultracapacitors that offers the highest level of energy density on the market. Through the use of patented graphene material, the new series boasts a capacitance of 4500 farads. By contrast, the closest competitor product has a capacitance of only 3400 farads. This is the single biggest increase in energy density for ultracapacitors in the past 15 years.



Energy density is a key development challenge for the ultracapacitor market and is fundamental if the technology is to eventually replace battery storage. The record-breaking energy density achieved by the SkelCap 4500 series will allow Skeleton Technologies to maximise opportunities in the heavy transportation and industrial markets where weight and space are at a premium.


“Graphene has long been heralded as a wonder material for a range of applications, including energy storage. However, a mass-market, graphene-based product has been slow to materialise. Our ultracapacitors will be that market breakthrough,” explains Skeleton Technologies’ CEO, Taavi Madiberk.


“We are harnessing the power of graphene to make the most significant advances in ultracapacitor performance seen for several years and this is resulting in strong customer demand ranging from aerospace to automotive applications.”


Skeleton Technologies ultracapacitors have already been chosen by the European Space Agency, where their use is expected to lead to significant cost savings by reducing the volume of heavy batteries required for energy storage. Next month, the company will be announcing the first ultracapacitor product for the hybrid truck market.

The new range has been designed for mass-market applications and the needs of systems engineers. The format has been developed to meet the industry standard of a 60 mm diameter cylindrical cell. Skeleton Technologies had previously offered prismatic cells, which are more compact in modular arrangements but more expensive to produce.

Skeleton Technologies has also achieved one the lowest ESR (equivalent series resistance) levels on the market at 0.095 mΩ. This factor is crucial as it greatly increases the efficiency of the cells by reducing the amount of energy that is lost as heat. For example, if a 3900A current is run through the SkelCap 4500 cell, it will lose only 0.30 joules per farad, whereas competing products can lose as much as 1.00 joules per farad.


“The ultracapacitor market is dominated by organic precursor carbon from coconut shell. It is the successful development of a graphene-based carbon that is allowing us to set new records for product performance,” explains Volker Dudek, Chief Technology Officer at Skeleton Technologies.


“We have set ourselves an ambitious technology development target of 20 Wh/kg by 2020, which is comparable with battery level energy density. With the launch of the SkelCap 4500 range we are already half way towards that goal.”


In the last month, Skeleton Technologies secured €9.8 million in Series B financing with a strategic investor in the electrical equipment market to ramp up the deployment of their graphene ultracapacitors.


Notes to Editors

Skeleton Technologies is Europe’s leading manufacturer of ultracapacitors, delivering high power, high energy, reliable and long-life storage solutions across industry. Through the use of patented nanoporous carbide-derived carbon, or ‘curved graphene’, we have achieved global breakthroughs in ultracapacitor performance. Our ultracapacitors deliver twice the energy density and 5 times the power density offered by other manufacturers.

In 2014 the company opened a 1000 m2 pilot plant and launched new SkelCap series ultracapacitors, which have gained considerable customer traction in the motorsport, automotive and aerospace sectors, among others. Our current customer base includes global engineering companies, the European Space Agency and several Tier 1 automotive manufacturers.

The company employees 47 people and has two subsidiaries: Skeleton Technologies GmbH located in Bautzen, Germany, which deals with manufacturing and sales; and Skeleton Technologies OÜ, located near Tallinn, Estonia, which handles R&D and pilot production.