Two Energy Stories To Start 2025

In 2025 the world will be even more obsessed with energy: from where to get it, to how much and how to store the surplus. Two stories that caught my eye as the year ended include:

• New material turns clothes into piezoelectric energy harvesters.
• A high-performance self-charging supercapacitor marks a milestone in energy storage.

The Latest Piezoelectric Energy Harvester

In the past, I have written about energy produced from roads with embedded piezoelectric harvesters that can continuously power electric vehicles, light roads and paths, and draw energy from shoes, cardiac pacemakers that use body movement to stay charged, and nano-sized devices for sensors that harvest energy from external vibrations.

Joining these is a three-dimensional stretchable harvester that can attach to skin or be embedded in clothes. Developed by the Daegu Gyeongbuk Institute of Science and Technology (DGIST) in South Korea, the technology incorporates lead zirconate titanate that normally is brittle, but in this case, has been made deformation insensitive. In other words, it can be stretched and shaped and put into clothing.

Lead zirconate titanate has a high piezoelectric efficiency. An article in the journal ACS Nano is entitled, Curvature-Specific Coupling Electrode Design for a Stretchable Three-Dimensional Inorganic Piezoelectric Nanogenerator. It describes the research into electrode design that has led to the development of embedded piezoelectrics tailored to provide a continuous circuit without energy losses. The researchers determined an inorganic thin film proved to be most effective for both the electrode design and energy harvesting.

The article concludes that the material represents a significant advancement in stretchable, wearable garments with embedded piezoelectric harvesting capability. Professor Kyung-In Jang, Associate Professor in the Department of Robotics and Mechatronics at DGIST, stated, “Developing this highly efficient stretchable piezoelectric energy harvester technology is a major achievement of this research. We expect this technology to become useful after commercialization and lead to the practical use of wearable energy harvesters.” 

Storage and Solar Self-Charging Supercapacitors Invented

Yet another invention from researchers at DGIST has produced a device that improves supercapacitors using transition metals such as manganese, cobalt, copper, iron, and zinc and integrates the result with a silicon solar cell.

This new energy storage device provides densities of 35.5 watt-hours per kilogram giving it the ability to deliver a powerful initial jolt, something capacitors are designed to do, while providing continuous reliable power thereafter with minimal performance degradation. It demonstrates resilience through multiple charge and discharge cycles.

The integration with a silicon solar cell produces a hybrid system with storage efficiencies of 63.%. That’s a high number and a critical energy metric that shows just how exciting is this invention. A December 30, 2024 article in the journal Energy, entitled Design of high-performance binary carbonate/hydroxide Ni-based supercapacitors for photo-storage systems describes using transition metals in a porous compound to create the self-charging device.

I have to add a personal comment. I read lots of scientific and engineering papers in researching this blog. This one was a particular pleasure. It was written without jargon-filled sentences and clearly described the fabrication process used to create the supercapacitor and how the high-performance silicon solar cell was integrated. The test results are provided in a recognized language. What a treat!

I tried to download the DGIST presser from which this Jeongmin Kim, Senior Researcher in the Nanotechnology Division quote comes. This was a bit of a trial requiring me to install a security app on my desktop which my system warned me not to do. So I chose to avoid the download and use the quote as reported by Kapil Kajal in an article he wrote for Interesting Engineering. This is the Kim quote:

“This study is a significant achievement, as it marks the development of Korea’s first self-charging energy storage device combining supercapacitors with solar cells. By utilizing transition metal-based composite materials, we have overcome the limitations of energy storage devices and presented a sustainable energy solution.”

So there you have it for the first day of 2025, two new energy-producing inventions that may help us to change the world. I expect to see many more novel solutions this decade and beyond as the world’s demand for energy increases and as we seek and find carbon-free, low-emissions energy solutions to help in our efforts to mitigate climate change in the 21st century.