There are many new battery technologies under development, but it is difficult to say which is the newest. Some of the most promising include lithium-air batteries, solid-state batteries, and nanowire batteries.
Lithium-air batteries have the potential to be much lighter and have a much higher energy density than current lithium-ion batteries. However, they are still in the early stages of development and have not yet been commercialized.
Solid-state batteries are another promising technology. They have the potential to be safer than current lithium-ion batteries, as they are less likely to catch fire or explode. However, they are also still in the early stages of development and have not yet been commercialized.
Nanowire batteries are a newer technology that is already being commercialized. They are made with nanowires that are just a few atoms wide. This makes them much smaller and more efficient than current batteries.