The approach of utilizing multivalent charge carriers could therefore circumvent the issue of a structural change within the working window and the halved occupation of the sodium sites leads to higher structural rigidity. Unfortunately, this also creates a longer diffusion path (no intermediate at Na2) and a more sluggish migration owed to the increased electrostatic interactions with the framework. An extensive overview over the properties of this material class can be found in the report of Alamo. 210