While both technologies store electrical energy, ultracapacitors and batteries use fundamentally different charge storage mechanisms. The end result of this difference is that batteries store about 100x the energy of ultracapacitors, while ultracapacitors can deliver about 100x as much power as batteries, and pay out that power over millions of cycles compared to thousands for batteries. But why the difference? Batteries store charge “Faradaically”, meaning that when batteries charge or discharge, positively charged ions need to be physically shuttled from one side of the battery to the other, balancing the external flow of electricity. Physically shuttling matter from one side of the cell to another makes batteries slow compared to ultracapacitors, but also means that they have higher energy density and can hold a charge for longer. Ultracapacitors store charge electrostatically using a phenomenon called an “electric double layer” (or EDL). This EDL discharges energy without any ion shuttling, meaning that it can provide almost instantaneous power!

Ultracapacitors today are associated with one byword in particular: power. Per unit mass, they are able to source about 100x as much power as a lithium-ion battery, and they can source that power over millions of cycles, not thousands. Currently, ultracapacitors are being used in cars to replace lead acid batteries, in support of critical grid services like frequency regulation and voltage support, in wind turbines for blade pitch control, and increasingly in applications where they are hybridized to support large lithium-ion battery deployments.

The greatest need for high energy density ultracapacitors comes in rapidly decarbonizing sectors: wind and solar on the power generation side, and buildings and EVs on the power consumption side. These sectors are increasingly using lithium-ion batteries for stable electric power, but this comes with a problem: lithium-ion—and in fact all battery technologies—are susceptible to “electrochemical shock” if they try to charge or disharge too quickly, which as electricity supplies become more variable is an all-too-present reality. Hybridizing with batteries, ultracapacitors can solve this problem by insulating batteries from injurious power spikes and ramps, forming what is called a HESS, or hybrid energy storage system. High energy density in ultracapacitors is critical for forming capital-efficient HESSs, as the energy required from ultracapacitors in these systems scales with the total energy stored in the batteries they protect.

Today’s ultracapacitor industry relies heavily on active material derived from coconuts grown in the South Pacific. Ultracapacitor active materials not made from coconut are instead derived from petroleum byproducts or coal. Using hemp, florrent can localize production of ultracapacitor active material to where it’s needed, and use a feedstock that is widely known for its rapid growth and sequestration of atmospheric CO2. florrent’s ultracapacitors can lock the carbon from hemp away in a solid mineral form, while not using a feedstock like coconut that is climate-change vulnerable and bakes significant emissions into its supply chain.