As more countries use solar panels and wind turbines to generate electricity, finding better ways to store that energy has become increasingly important.
Researchers at UCLA have developed a promising new battery technology that could make large-scale energy storage cheaper, longer-lasting, and more efficient.
The new study, published in the journal Small, describes a zinc-ion hybrid battery that can store more than seven times as much energy as similar zinc-based devices.
The researchers also created a new 3D-printed testing system that could help scientists evaluate future battery technologies more accurately.
Most rechargeable batteries today rely on lithium, but lithium is relatively expensive and can be difficult to mine and recycle.
Zinc offers an attractive alternative because it is around 100 times more abundant than lithium, costs less, and is easier to recycle.
These advantages make zinc a strong candidate for storing renewable energy on a large scale.
The battery developed by the UCLA team is known as a hybrid because it combines features of both a battery and a supercapacitor.
One side works like a traditional rechargeable battery, storing large amounts of energy.
The other side behaves like a supercapacitor, which can charge and discharge very quickly and is designed to last for many years.
One limitation of ordinary supercapacitors is that they can only store energy on the surface of their electrodes. To overcome this problem, the researchers designed a new carbon electrode with an enormous surface area.
Using advanced 3D printing, they created a structure that looks like a tiny honeycomb or sponge filled with countless microscopic holes.
After printing, the material was heated and chemically treated until only a highly conductive carbon framework remained. The researchers then filled this structure with vanadium oxide, a material known for its excellent ability to store electrical energy.
The result was a remarkable increase in storage capacity. The researchers estimate that if just one gram of the material could be spread flat, it would cover an area roughly equal to 10 tennis courts.
This huge surface area provides many more places for electrical charge to be stored.
Testing showed that the new battery stored more than seven times the energy of comparable zinc-ion hybrid devices. Even after 1,500 charging and discharging cycles, it still retained 82% of its original storage capacity, suggesting good long-term durability.
The team also addressed another common challenge in battery research. Many laboratories still test experimental batteries in simple open containers filled with liquid electrolyte.
Over time, the liquid evaporates, making the batteries fail sooner and reducing the accuracy of test results.
To solve this problem, the researchers designed a low-cost 3D-printed test cell with a sealed lid that prevents evaporation. The design also keeps the battery electrodes at a fixed distance from each other, producing more reliable and consistent measurements.
When the team compared the new testing device with traditional open-container methods, the improvement was striking.
Batteries tested in the sealed cell retained 98% of their charge after 1,500 cycles, while those tested in open containers failed before reaching 100 cycles.
The researchers hope both innovations will accelerate the development of safer, more affordable energy storage systems that support the growing use of renewable energy around the world.
