The National Institute for Materials Science (NIMS), in collaboration with Seikei University, has successfully enhanced the power output of lithium-air batteries, which are attracting attention as next-generation batteries. By developing a highly porous electrode made of carbon nanotubes, the team achieved a tenfold increase in output current. The lithium-air battery developed in this study not only has extremely high energy density compared to lithium-ion batteries but also significantly improved power performance.

As a result, it is now able to supply the power required for hovering small drones, making significant improvements in flight duration feasible. These results were published online in the Journal of Power Sources on February 9, 2025.

Lithium-air batteries (LABs) are rechargeable batteries that operate through discharge and charge reactions using lithium and oxygen. They are attracting attention as an energy storage technology capable of achieving significantly lighter weight and larger capacity than conventional lithium-ion batteries, with a potential energy density 5 to 10 times higher. However, lithium-air batteries have extremely slow reaction kinetics, resulting in only very weak output current. To make use of the large amount of energy stored in lithium-air batteries, a fundamental improvement in their power output has been required.

The research team developed a highly porous carbon nanotube air electrode that significantly improved oxygen accessibility. When combined with a low-viscosity amide-based electrolyte, the new design enabled a tenfold increase in current density. The resulting battery achieved a specific power density sufficient to support hovering in lightweight drones.

Based on these results, the team aims to scale up lithium-air battery cells, with the goal of developing ultra-lightweight and high-capacity batteries that can be used as power sources for small drones and microrobots.

Looking to upgrade the audio for your phone or action camera footage? Amazon is offering $60 off the DJI Mic Mini kit. Our reviewer gave DJI’s lavalier mic, a 7/10 and this kit includes two mics, a receiver, and a handy charging case. That’s the lowest price yet for this bundle at just $109, and it’s a great value on this easy-to-use and lightweight microphone.

These little mics and their fuzzy windscreens have become increasingly popular over the last year, popping up on collars and in the hands of YouTubers and livestreamers across a number of social media platforms. They sound crisp and clear, and they do a great job of cutting out all the ambient noise that smartphone mics tend to pick up when recording.

They’re also generally very easy to use, with iPhones automatically preferring the wireless mics, and Android phones just needing them selected in the camera app. They have much better battery life than the slightly older and fancier DJI Mic 2 (9/10, WIRED Review), partially because they don’t record locally, but they’re a lot cheaper and lighter in return.

While you can buy the individual bits à la carte, the bundles includes two of the wireless microphones, the wireless receiver, a set of windscreens in two colors, all the charging and connective cables you’ll need for both cameras and phones, and a charging case for the mics and receiver. You can also pick up a receiver and mic on their own for just $59, but given all the small bits and parts, the kit seems well worth the extra cash.

Our reviewer, Julian Chokkattu, did find the setup required a bit of manual dexterity, which tends to come with the territory. The receiver, for example, plugs directly into your phone, and you shouldn’t need to take your case off, but it requires a surprising amount of force to connect or disconnect. The reduced footprint also means it’s easy to lose some of the smaller bits and plastic covers. There were some oddities with the app, too, involving updates and connection types, but nothing that’s cause for concern once you have everything set up the way you like.

Northern Ireland police failed to disclose two covert surveillance operations against journalists to the UK’s independent surveillance watchdog in breach of their statutory obligations.

The Police Service of Northern Ireland kept inspectors from the Investigatory Powers Commissioner’s Office (IPCO) in the dark about two covert operations against  journalists in 2018 and 2023, it has been disclosed.

Brian Leveson, the investigatory powers commissioner, confirmed in a letter to Northern Ireland’s policing board that the PSNI only informed IPCO about the covert operations in 2025, after they had become public.

The disclosure, in letters published in the Northern Ireland Policing Board’s annual human rights report, first reported by The Detail, comes as the PSNI is preparing to publish a review by barrister Angus McCullogh KC into police surveillance of journalists and lawyers in Northern Ireland.