The Quiet Revolution of Solid-State Batteries. Solid-state batteries are considered the next generation of energy storage, promising to replace conventional liquid-electrolyte lithium-ion batteries with safer, more efficient solid materials (ceramic, sulfide glass, or polymers). This technology is often referred to as a "quiet revolution" because, while not always in the headlines, it is rapidly moving from laboratory prototypes to practical applications in electric vehicles (EVs) and consumer electronics.