Capacitors, the unsung heroes of energy storage, play a crucial role in powering everything from smartphones to electric vehicles. They store energy from batteries in the form of an electrical charge and enable ultra-fast charging and discharging. However, their Achilles’ heel has always been limited energy storage efficiency.

Researchers at Washington University in St. Louis have unveiled a groundbreaking capacitor design that could overcome these energy storage challenges. In a study published in Science, lead author Sang-Hoon Bae, an assistant professor of mechanical engineering and materials science, demonstrates a novel heterostructure that curbs energy loss, enabling capacitors to store more energy and charge rapidly without sacrificing durability.

While batteries excel in storage capacity, they fall short in speed, unable to charge or discharge rapidly. Capacitors fill this gap, delivering the quick energy bursts that power-intensive devices demand. Some smartphones, for example, contain up to 500 capacitors, and laptops around 800. However, capacitors traditionally struggle with long-term energy storage.

Within capacitors, ferroelectric materials offer high maximum polarization, useful for ultra-fast charging and discharging, but they can limit the effectiveness of energy storage. The new capacitor design by Bae addresses this issue by using a sandwich-like heterostructure composed of 2D and 3D materials in atomically thin layers, bonded chemically and non-chemically. This structure, just 30 nanometers thick (about 1/10th the thickness of an average virus particle), allows for precise control over the relaxation time of a conductor, enhancing energy storage efficiency.

“Initially, we weren’t focused on energy storage, but during our exploration of material properties, we found a new physical phenomenon that we realized could be applied to energy storage,” Bae explains. This discovery led to the development of a semiconducting material that can store energy with a density up to 19 times higher than commercially available ferroelectric capacitors, achieving 90 percent efficiency.

The study team plans to continue optimizing the material structure to ensure ultrafast charging and discharging with a new high-energy density. Bae emphasizes the importance of maintaining storage capacity over repeated charges to make this material suitable for larger applications, such as electric vehicles.

“This new physical phenomenon enables us to manipulate dielectric material in such a way that it doesn’t polarize and lose charge capability,” Bae says. The team’s ongoing work could lead to highly efficient energy storage systems, potentially revolutionizing the field and providing significant advancements for various electronic devices.

The research marks a significant step forward in energy storage technology, paving the way for capacitors that can keep up with the demands of modern electronic devices and applications.

By Impact Lab