Satechi's new Slim EX keyboards have a replaceable battery
Satechi's Slim EX1 and EX3 wireless keyboards feature ultrathin designs with user-replaceable rechargeable lithium batteries accessed via an underside compartment and support multi-device pairing.
portable split keyboard with flat circular 'mouse' fits tray tables on airplanes and trains
The Toucan is a wireless portable split keyboard with a built-in flat circular trackpad, pixel display, Bluetooth and customizable Kailh Choc switches.
Logitech's Solar-Powered Keyboard Is Back, and It's Still Pretty Basic
Logitech's Signature Slim Solar+ K980 is a solar-powered full-size office keyboard with no charging port, offering infinite battery life but mediocre typing and high price.
Soleil Mechanical TKL Keyboard Powers Up with Ambient Light and Style - Yanko Design
The Soleil promises up to 10 months of battery life with normal use in complete darkness, and with regular ambient light from your setup, it offers 12 months or more of wireless freedom.