Researchers at Tohoku University have developed an iron-based catalyst that improves the performance of zinc-air batteries, a technology viewed as a lower-cost alternative to lithium-ion systems for energy storage.

The team focused on overcoming a key limitation of the oxygen reduction reaction (ORR) in zinc-air batteries. While zinc-air batteries draw oxygen from the surrounding air instead of storing it internally, the ORR process is relatively slow, restricting overall battery performance.

To address the problem, the researchers engineered a heterointerface combining iron oxide (Fe2O3) and samarium oxide (Sm2O3). The interface altered how electrons behave at the catalyst surface, helping speed up reaction kinetics and improve battery efficiency.

According to the researchers, the catalyst weakens excessive bonding between iron sites and hydroxyl intermediates, allowing the reaction to proceed more smoothly and reducing one of the major bottlenecks in zinc-air battery operation.

Reworking battery chemistry

Fe2O3 was selected because it is abundant, inexpensive and stable under the alkaline conditions commonly found in zinc-air batteries. However, iron-based catalysts typically suffer from strong Fe-OH interactions that slow the release of reaction products.

The newly developed Fe2O3/Sm2O3 interface was designed to overcome that limitation. Researchers said charge redistribution, orbital hybridization and spin modulation at the interface helped optimize the catalyst’s behavior during oxygen reduction.

As a result, the catalyst delivered faster ORR kinetics and improved durability compared with conventional approaches. The work also avoided the use of expensive noble metals, which are commonly used in high-performance catalysts.

The team evaluated the material in both liquid and flexible all-solid-state zinc-air batteries. Beyond laboratory measurements, the researchers demonstrated practical operation by powering a small LED lamp and charging a smartphone.

“The catalyst achieves high ORR activity, improved reaction kinetics, excellent durability, and superior performance in both liquid and flexible all-solid-state zinc-air batteries,” said Hao Li, distinguished professor at the Advanced Institute for Materials Research (WPI-AIMR).

Beyond precious metals

Zinc-air batteries have attracted attention because they use widely available materials and can theoretically deliver high energy density. Unlike lithium-ion batteries, they rely on oxygen from the atmosphere as part of the electrochemical process.

Researchers believe improving catalyst performance could help make the technology more practical for real-world applications, including portable electronics, wearable devices, and large-scale energy storage systems.

“For the general public, this means that we may be closer to affordable and sustainable clean-energy technologies,” Li said.

The researchers say the study demonstrates a potential pathway toward lower-cost energy storage by replacing precious-metal catalysts with more abundant materials while maintaining strong electrochemical performance.

Future work will focus on expanding the interfacial spin-regulation strategy used in the study and exploring whether similar approaches can improve other energy-conversion and storage technologies.

The findings were published in Angewandte Chemie International Edition.

The Department of War has released a third batch of declassified records tied to unidentified anomalous phenomena (UAP), adding 72 files that describe unexplained sightings reported by military personnel, federal agents, and foreign observers.

The release is part of the PURSUE program, launched after President Donald Trump directed federal agencies to identify, review, and declassify records related to UFOs, UAPs, and potential extraterrestrial activity.

The newly released documents do not provide evidence of alien life or a government cover-up. Instead, they offer additional details about several unresolved cases that investigators have been unable to conclusively explain.

According to the Department of War, unresolved cases are incidents where available data is insufficient to determine the nature of the observed object or phenomenon.

Strange objects, few answers

One of the most detailed reports involves a February 2022 sighting near Colorado Springs, Colorado. Five US Army personnel at Fort Carson reported seeing an unusual object hovering above Cheyenne Mountain.

“The object was ‘potato’ shaped with distinct edges and appeared to look painted in a creamy/whitish opalescent color,” an FBI document states. Witnesses said the object appeared to consist of “articulating fish scales or panels that were non-symmetrical, non-overlapping and irregular shaped.”

According to the report, the object remained stationary for roughly two minutes before disappearing. No photographs or videos were captured.

Investigators later assessed with “low confidence” that the sighting may have resulted from sunlight reflecting off snow-covered terrain and illuminating clouds. However, witnesses reported clear skies, and investigators found no evidence of balloons, aircraft, or known foreign technology in the area.

Another case involved six federal law enforcement agents who reported repeatedly observing bright orange and red orbs in October 2023. According to the documents, the objects appeared above a ridgeline and, in some instances, seemed to generate additional smaller orbs.

An analysis conducted by the Pentagon’s All-Domain Anomaly Resolution Office reviewed several possible explanations, including military exercises and flare deployments occurring nearby. The report said those explanations were plausible but not conclusive and noted that the observations could involve “unrecognized technology.”

Global reports surface

The latest release also includes an FBI report describing a 2025 sighting in the northeastern United States. A witness reported seeing a bright red sphere near a wooded area.

“Inside the red sphere, at the center, there appeared to be what (redacted) described as a ‘white plasma sun’ about the size of a basketball,” the report states.

The witness said a second sphere appeared before both objects departed silently. The file includes cellphone footage showing two glowing red objects moving across the sky. The White House later shared the video online while referencing the case.

Among the older documents is a CIA report from Zimbabwe dating to 2008. Witnesses near the country’s main airport described a disc-shaped object with rotating lights.

“At one point during observation, ‘beams’ were observed emanating from the object,” the report states.

So far, the Trump administration’s disclosure effort has resulted in the release of roughly 300 UAP-related files dating back to the 1940s. The Department of War said additional records will be released in future tranches as reviews and declassification efforts continue.