Solid state batteries don't over-heat or catch on fire, they operate even when damaged & tolerate a range of temperatures.Importantly for e-aviation, they can be stacked on top of each other without casings, making them lighter than lithium-ion alternatives.Unfortunately, they discharge their power slowly. That is not ideal if you need to rapidly increase power consumption, such as when applying thrust.But NASA researchers have managed to increase their solid-state battery’s discharge rate by a factor of 10 – and then by another factor of 5 - in the last year.  https://www.nasa.gov/aeroresearch/nasa-solid-state-battery-research-exceeds-initial-goals-draws-interest

Lithium-ion batteries are currently winning the rechargeable battery wars. But for how long?  Sodium-ion batteries, while not as energy dense or as long-lasting are cheaper (around 25-30% cheaper) and use materials that are considerably easier to source.Scientists in this article have gone even further in their pursuit of lower costs, noting a toxic member of the carrot family, Hogweed, can be used to make a decent hard carbon to support the battery's electrochemical performance. What's more, if you run out, it is a fast-growing plant! https://www.pv-magazine.com/2022/10/13/sodium-ion-battery-anode-made-from-toxic-hogweed/com)

For years the faster-charging, higher energy density, lighter weight, greater safety benefits of solid-state batteries (SSB's) for EV's have seemed out of reach, due in part to some significant disadvantages, including a short battery life! But a US start-up thinks it might have a break-through that could just mean the promise of SSB's might yet be realised.https://news.harvard.edu/gazette/story/2021/05/researchers-design-long-lasting-solid-state-lithium-battery/

Lithium-ion batteries typically rely on two different types of chemical reaction to generate energy - Lithium iron

Currently less available of all the three main electrolyser technologies, solid oxide electrolysers utilise both electricity and high temperature to produce green hydrogen. This unique feature makes it potentially more advantageous for industrial sites seeking to decarbonise. But this Topsoe production site might just help make the units more prevalent!https://globalenergyprize.org/en/2022/09/06/the-worlds-largest-electrolyser-plant/

Scientists in Australia have produced extremely pure (99+%) hydrogen using moisture captured from the air and electrolysis powered by the sun. The technology is known as Direct Air Electrolysis (DAE) and poses a very real promise for water-scare regions.Even more impressive when you think that it can operate in locations with relative humidity levels as low as 4%. As a point of comparison, the average daytime relative humidity at Uluru (Ayers Rock) in the central desert of Australia is (apparently!) 21%.https://www.inkl.com/news/out-of-thin-air-new-solar-powered-invention-creates-hydrogen-fuel-from-the-atmosphere/YjvnXYIqbl