Semi-Solid, Quasi-Solid, and Condensed Batteries
Semi-solid, quasi-solid, and condensed batteries are overlapping labels used for alternatives to conventional liquid-electrolyte cells, but they do not describe one standardized battery architecture.
Main forms
- Semi-solid: often means that a cell combines solid components with some liquid or gel electrolyte. The same wording is also used for slurry-electrode systems, so the label alone does not identify the cell construction.
- Quasi-solid: commonly describes a gel or hybrid electrolyte in which liquid is immobilized in a polymer or combined with another ion-conducting material. There is no universal liquid-content threshold that separates quasi-solid from semi-solid.
- Condensed: is not a general battery classification. CATL, for example, uses condensed battery for a product family built around its proprietary condensed-state electrolyte and other cell technologies. CATL: Condensed battery launch
How the terms differ
The useful distinction comes from the electrolyte's composition and its main ion-conduction mechanism. Research literature notes that labels such as semi-solid, quasi-solid, hybrid, and almost solid leave the electrolyte architecture open to interpretation. Advanced Science: Typology of battery cells from liquid to solid electrolytes
None of these labels, by itself, reveals how much liquid remains, the electrode materials, required pressure, energy density, charging performance, durability, safety, production yield, or cost. An all-solid-state cell is intended to conduct ions through solid materials throughout the cell; see Solid-State Battery for that boundary.
For a deeper explanation of electrolyte and electrode choices, see Cell Chemistry & Components. For current commercial, validation, pilot, and announced battery programmes, see Latest Advances in EV Battery Technology.