Solid State

A solid-state battery (SSB) is an electrical battery that uses a solid electrolyte to conduct ions between the electrodes, instead of the liquid or gel polymer electrolytes found in conventional batteries. Theoretically, solid-state batteries offer much higher energy density than the typical lithium-ion or lithium polymer batteries. While solid electrolytes were first discovered in the 19th century, several problems prevented widespread application. Developments in the late 20th and early 21st century generated renewed interest in the technology, especially in the context of electric vehicles. As of 2026, the solid-state battery market has yet to reach scalability and commercialization. Solid-state batteries can use metallic lithium for the anode and oxides or sulfides for the cathode, improving energy density. The solid electrolyte acts as an ideal separator that allows only lithium ions to pass through, allowing solid-state batteries to potentially solve many liquid electrolyte Li-ion battery problems: flammability limited voltage unstable electrode interface formation poor cycling performance strength. Materials proposed for use as solid electrolytes include ceramics (e.g., oxides, sulfides, phosphates), and solid polymers. Solid-state batteries are found in pacemakers and in RFID and wearable devices. These batteries offer enhanced safety and higher energy densities. To achieve to widespread adoption over lithium ion batteries, solid-state batteries need to overcome many challenges: energy and power density durability material costs sensitivity stability.