Ignition plug and method for the ignition of a fuel-air mixture by means of an ignition plug of said type

An ignition plug for igniting a fuel-air mixture in a cylinder of a direct-injection, applied-ignition internal combustion engine, comprising:

• an ignition plug having at least one electrode pair which comprises two electrodes which are electrically insulated with respect to and spaced apart from one another, of which a first electrode serves as a ground electrode and surrounds a second electrode, a spacing between the first electrode and the second electrode in an ignition gap, in which a spark path forms during a course of an applied ignition, being variable, wherein at least one of the two electrodes is designed to be movable for the purpose of adjustment of the spacing in the ignition gap, for which purpose an adjustment device is provided, and wherein the adjustment device includes a temperature-reactive wax element that is arranged in a working chamber and above a spring, the spring above the second electrode, and when the temperature-reactive wax is activated by an increase in temperature, the wax is positioned to expand against a spring force to move the second electrode.