According to supposed leaks from Apple's supply chain, the next iteration of the iPad Air (the iPad Air 3) will have some notable upgrades. The report indicates the iPad Air 3 will have 4GB or RAM and a 4K resolution touchscreen display.
Along with this intel, the report suggests the iPad Air 3 will also have improved battery life, although the specifics of the battery size were not shared. Here's a quote with the details,
Of course, take this rumor with a grain or several of salt. DigiTimes has a 50/50 record with accurate leaks.