Finally someone has improved on the millennia-old axe for splitting wood by hand! Behold: The Vipukirves, or Leveraxe.
So what makes a lever different than a wedge in this scenario? The Vipukirves still has a sharpened blade at the end, but it has a projection coming off the side that shifts the center of gravity away from the middle. At the point of impact, the edge is driven into the wood and slows down, but the kinetic energy contained in the 1.9 kilogram axe head continues down and to the side (because of the odd center of gravity). The rotational energy actually pushes the wood apart like a lever. A single strike can open an 8 cm gap in a log, which is more than enough to separate it.
Simple and brilliant. Also easy to mechanize.