For years, supercapacitors—also known as ultracapacitors—have lingered on the periphery of electric vehicle technology. While conceptually simple, their use in production has been limited, with examples like the Lamborghini Sián showcasing their potential. However, a Basingstoke-based company, Allotrope Energy, believes it has developed a breakthrough that could finally bring supercapacitors into the mainstream, particularly for hybrid vehicles.
What are Supercapacitors and Why Haven’t They Been Widely Adopted?
Supercapacitors are electrical storage devices found in almost every electronic product. Like batteries, they store and release electricity. However, key differences exist. Supercapacitors comprise two electrodes separated by an insulating layer. When connected to a voltage, an electrical charge accumulates on these plates. Crucially, unlike batteries, no chemical reaction takes place during charging or discharging, allowing supercapacitors to charge and discharge much faster.
Historically, the major drawback of supercapacitors has been their low energy density. Batteries can store large amounts of energy for extended periods, whereas supercapacitors release their charge relatively quickly when connected to an electrical load, like a motor. This difference has led to batteries dominating the electric vehicle and hybrid car market.
Allotrope Energy’s Breakthrough: Lignavolt Supercapacitors
Allotrope Energy claims to have overcome this limitation with its new Lignavolt supercapacitors. These devices boast an energy density of 4-15Wh/kg, significantly higher than the 7-8Wh/kg found in existing supercapacitor technology. Furthermore, they are reportedly a fraction of the cost to produce. The secret behind this advancement lies in the use of Lignavolt material—a sustainably produced substance derived from lignin, a waste product of the paper industry.
The Potential for Hybrid Vehicles
The potential application of this technology is particularly exciting for hybrid vehicles. These cars combine an internal combustion engine (ICE) for range with an electric motor and a battery or supercapacitor to capture and reuse energy through regenerative braking, which is the process of converting the kinetic energy of the car into electricity during deceleration.
Early examples of supercapacitor use in hybrid technology date back over two decades, with Honda’s FCX fuel cell vehicle utilizing supercapacitors to store energy harvested from its fuel cell system and regenerative braking. However, massive investments in battery technology for high-voltage EVs, 48V mild-hybrid vehicles, and other applications has overshadowed supercapacitors.
Allotrope argues that capturing 100% of regenerative braking energy, even during moderate braking, would require an impractically large and expensive lithium-ion battery. In contrast, their 1kg supercapacitor could provide 75 horsepower—a figure 50 times greater than an equivalent lithium-ion battery.
A Smaller Engine, Lower Emissions
The company envisions a future where more of a hybrid powertrain’s acceleration comes from the electric motor, powered by the supercapacitor. This would allow manufacturers to reduce the size of the internal combustion engine, ultimately leading to lower emissions and reduced fuel consumption. The implications for hybrid vehicle efficiency and environmental impact could be significant.
In conclusion, Allotrope Energy’s Lignavolt supercapacitors represent a promising advancement in electrical storage. Their improved energy density, cost-effectiveness, and sustainable production methods position them as a potential game-changer, particularly for hybrid vehicles seeking to optimize regenerative braking and improve overall efficiency. This tiny box from Basingstoke may well be on its way to reshaping the future of hybrid technology.
