AbstractThe structure of lithium sorbate (C6H7LiO2) was determined by single‐crystal X‐ray diffraction. It may be divided into organic and inorganic layers. The ionic part of the structure consists of a two‐dimensional network of corner‐ and edge‐sharing lithium oxotetrahedra, a structural pattern already known from other lithium carboxylates. Irradiation of the substance with X‐rays or its thermal treatment results in the formation of a polymer exhibiting ionic conductivity at higher temperatures. Due to the rather large distances between potentially reactive atoms the polymerization results in a structural breakdown. Nevertheless, during the solid‐state polymerization preferred orientations of building units are partially preserved. The probable course of the polymerization and the structure of the resulting polymer are discussed.