Traditionally there are two ways to store energy: in batteries or in capacitors. The new ‘ultracap’ technology, which VITO helped develop, combines the best of both: it offers the energy storage of a battery and the life of a capacitor.

Batteries and capacitors each have their advantages and disadvantages. A capacitor can store less energy than a battery, but its capacity is greater and the lifetime much longer. Capacitors are therefore perfectly suited to frequent short trips, for example with hybrid city buses. Every time the bus accelerates and decelerates, the energy is discharged and recharged. A capacitor can sustain this cycle about a million times. A battery can store more energy, but can handle at most five thousand charging cycles. The KIC project HYDEALIST aims to combine the benefits of both systems.

More energy, longer life cycle

“HYDEALIST was inspired by the French company NAWA Technologies. It managed to build ultracaps that can store three times more energy than the traditional versions, without sacrificing useful life cycle,” says battery researcher Peter Coenen of VITO. “Ultracaps are ideal for automated guided vehicles (AGVs): these are driverless vehicles that can, for example, retrieve parts in a warehouse. Conventional batteries for AGVs have to be replaced every two to three years. The new compact ultracaps can easily last ten years.”

VITO's role

Within HYDEALIST, VITO is responsible for the integration of the ultracaps in the AGVs. Like batteries, the ultracaps are combined in a package. An energy management system manages the operation of the caps and lets you know when they are (almost) empty. “The project extends over three years. Prototypes of ultracaps for AGV vehicles should be available by the end of 2019,” says Peter Coenen. “There is also a commercial plan to use them in forklifts. Many more applications are conceivable in the longer term. The new ultracaps close the gap between conventional capacitors and batteries.”