A chemical engineer says his discovery of a ‘missing link’ to describe the movement of ions within supercapacitors could lead to laptops and phones that can be charged in just one minute and electric cars in less than ten.
Previously, Kirchhoff’s Law, which has successfully described the movement of electrons since 1845, was limited in its definition. This resulted in an engineering roadblock that has prevented the adoption of supercapacitors to replace lithium-ion batteries in commercial applications.
Now, Ankur Gupta, a chemical engineer from the University of Colorado at Boulder, says his findings modify Kirchhoff’s law in a way that allows engineers to model and predict the movement of ions across a network of thousands of interconnected pores like those found in electric double-layer supercapacitors.
“That’s the leap of the work,” Gupta said of his modification to Kirchhoff’s Law. “We found the missing link.”
Lithium-ion batteries and Supercapacitors
Although batteries and capacitors both store electricity, each has its distinct advantages and disadvantages. For example, batteries can store significantly more energy than capacitors. Supercapacitors close that gap somewhat, but on average, lithium-ion batteries can store ten times as much energy. This ability has made batteries the standard in home electronics and electric vehicles alike, as devices using supercapacitors would need to be charged much more often than those using batteries.
Conversely, batteries accumulate and release charge ten times slower than supercapacitors. This has resulted in laptops that can take over an hour to charge and electric cars that can take even longer. Unfortunately, supercapacitors leak their charges much more quickly than batteries. According to Car Magazine, “If you left a supercapacitor-powered car in the garage for a week, for example, you’d likely find it with no charge when you returned.”
There have been some efforts to combine the technologies, including using supercapacitors in regenerative braking or even employing supercapacitor-fueled buses that can quickly recharge at every stop. Lamborghini even employed supercapacitors in its 800-hp all-electric Sian supercar to offer quick bursts of extreme power. Still, those applications are the exception, leaving supercapacitors and their advantages sitting on the sidelines while batteries have become the industry standard for energy storage.
Rewriting Kirchhoff’s Law to Improve Energy Storage
After analyzing the limitations of supercapacitors, Gupta wondered if approaching the problem from the perspective of a chemical engineer could offer him a unique perspective.
“Given the critical role of energy in the future of the planet, I felt inspired to apply my chemical engineering knowledge to advancing energy storage devices,” Gupta said. “It felt like the topic was somewhat underexplored and, as such, the perfect opportunity.”
Specifically, Gupta wondered if the movement of ions in supercapacitors was similar to the movement of other fluids in similar porous environments. If so, he figured that current engineering methods could be improved through computer modeling, which could result in supercapacitors with much higher energy storage potential.
“The primary appeal of supercapacitors lies in their speed,” Gupta explained. “So how can we make their charging and release of energy faster? By the more efficient movement of ions.”
As noted, Kirchoff’s Law, which has been accepted science for nearly two centuries, was the primary barrier. However, when studying its application in energy storage, Gupta saw that it only seemed to apply to the movement of electrons in one single pore. In supercapacitors, ions accumulate in a vast network of thousands of interconnected pores, meaning the law simply wasn’t designed to address the situation.
According to Gupta and his co-authors’ research, published in the Proceedings of the National Academy of Sciences, understanding the dynamics of charging in porous media like supercapacitors “is essential for advancements in next-generation energy storage devices.”
Applying Chemical Engineering Techniques to the Movement of Ions
To try this new approach, Gupta applied chemical engineering techniques used to study flow in porous materials, such as oil reservoirs and water filtration systems. This also involved developing customized modeling software to better characterize how ions might move in similar structures. As hoped, his efforts resulted in a new way of predicting the movement of ions in porous materials, which could increase the energy efficiency of supercapacitors.
“Our network model provides results up to six orders of magnitude faster,” Gupta and his co-authors explain, “enabling the efficient simulation of a triangular lattice of five thousand pores in 6 min.”
While faster charging cars, laptops, and phones may be the goal, Gupta’s team also believes that their work could move beyond energy storage for these industries alone. This includes potential applications across a wide range of products and systems, including “improving supercapacitor design and enabling 3D-printed microscale electrodes for wearable energy storage and supercapacitors in Internet-of-Things applications.”
“The discovery is significant not only for storing energy in vehicles and electronic devices but also for power grids, where fluctuating energy demand requires efficient storage to avoid waste during periods of low demand and to ensure rapid supply during high demand,” the press release announcing the team’s findings adds.
Christopher Plain is a Science Fiction and Fantasy novelist and Head Science Writer at The Debrief. Follow and connect with him on X, learn about his books at plainfiction.com, or email him directly at christopher@thedebrief.org.