- -Micro-Hybrids and Ultracapacitors (Bnet.com)
"Bohn said that ultracapacitors have power density hundreds of times greater than lithium-ion batteries. And he said they can greatly reduce costs by helping 'transform an $8,000 battery into a $4,000 all-electric drivetrain system.' "
- -Supercapacitors in Hybrid Cars vs Batteries (Green.AutoBlog.com)
"A presentation made by Belgian researchers at Electric Vehicle Symposium (EVS) 27 in Barcelona might irk fans of battery-driven EVs. A new study found that the numbers prove fuel cell hybrid electric vehicle (FCHEV) powertrains partnered with supercapacitors have better fuel economy than powertrains that blend a fuel cell and a battery." 01-14
- -Ultracapacitors (CNET.com)
"More companies are pursuing ultracapacitors for energy storage because they have different characteristics than batteries. By volume, batteries can store more energy but ultracapacitors can quickly charge and discharge electrical energy and they degrade very little over time."
"Ultracapacitors and batteries could be used in a single vehicle with the batteries storing the energy for a longer range and the ultracapacitor providing power for acceleration and absorbing energy from regenerative braking. In grid storage, ultracapacitors on their own can be used for frequency regulation, where quick bursts of energy are needed to maintain a steady frequency or voltage, Luebbe said."
- -Ultracapacitors (NREL.gov)
"An ultracapacitor, also known as a double-layer capacitor, polarizes an electrolytic solution to store energy electrostatically. Though it is an electrochemical device, no chemical reactions are involved in its energy storage mechanism. This mechanism is highly reversible, and allows the ultracapacitor to be charged and discharged hundreds of thousands of times."
"An ultracapacitor can be viewed as two nonreactive porous plates, or collectors, suspended within an electrolyte, with a voltage potential applied across the collectors."
"However, it stores a much smaller amount of energy than does a battery. Since the rates of charge and discharge are determined solely by its physical properties, the ultracapacitor can release energy much faster (with more power) than a battery that relies on slow chemical reactions."
"The use of ultracapacitors for regenerative braking can greatly improve fuel efficiency under stop-and-go urban driving conditions. Only ultracapacitors can capture and store large amounts of electrical energy (generated by braking) and release it quickly for reacceleration."
- -Ultracapacitors: Problems and Advantages (PopularMechanics)
"The problem with capacitors--and the reason they've taken such a back seat to batteries since they were first stumbled upon in the '60s--is capacity. Even ultracapacitors can manage only a fraction of the power of a lead-acid or lithium-ion battery. So the recipe for a better ultracapacitor is more surface area. Researchers have already expanded capacity with the addition of activated carbon coatings, which are porous enough to provide an effective surface area that's 10,000 times greater than the materials previously used to gather ions."
"By replacing the porous activated carbon used in ultracapacitors with tightly bunched nanotubes, Schindall believed that the ion-collecting surface area could be increased by as much as five. Since current ultracapacitors can store around 5 percent of the energy in an equivalent-size battery, the addition of nanowires could bring this up to 25 percent."
"Those applications could include not only electric vehicles, where the benefits of unlimited charge cycles and less overload-prone storage are clear, but in hybrid cars as well."