The solid-state batteries that are on the market today are thin-film batteries, which, on account of their limited capacity, can only be used for micro-storage, for example to provide power for sensors. But as a result of innovations in materials and architecture, solid-state batteries may soon be used also for large storage systems, for example for electric cars or the smart grid. The development of solid-state electrolytes with high Li-ion conductivity is an important link in achieving that aim. At imec, a nano-composite electrolyte has been developed which can bring solid-state batteries one step closer to the market.