mechanical structure of solid state batteries

The general structure of a (lithium) cell is usually very similar. Basically, a battery consists of two electrodes (anode and cathode) and a separator. The two electrodes are located in an electrolyte, which allows ions to move through the cell. The separator separates the anode and cathode. It is permeable to ions, but acts as a barrier for electrons. The anode and cathode are each connected to a current collector (copper or aluminum). The current arresters are then the plus and minus pole of the respective battery. [1, p.14ff].

Normally, the electrolyte is in a liquid or gel form (lithium polymer batteries). Due to its viscosity, the electrolyte can contact the two electrodes very well. The idea of solid state batteries is now to replace the liquid or gel electrolyte with a solid electrolyte. The solid electrolyte also acts as a separator, so that the separator is no longer an independent component [2 p. 2]. 

Within solid state batteries, there is a distinction between all solid state batteries (ASSB) and semi solid state batteries (SSSB). All solid state batteries use only a solid electrolyte. Semi solid state batteries represent a hybrid variant between all solid state batteries and conventional batteries with liquid electrolyte: in addition to the solid electrolyte, there is also a liquid electrolyte that takes up a few percent by volume, which improves the contact between the electrolyte and the electrodes. The improved contacting results in significantly lower internal resistance and thus higher performance [3]. Figure 1 shows the structure of the different technologies.