Ionogels based on a chemically cross-linked polysaccharide matrix and a hydrophobic ionic liquid offer a sustainable alternative to petrochemical-based polymer electrolytes. These newly obtained cellulose-based ionogels present the flexibility, thermal stability and high ionic conductivity of a liquid; this latter property can be further enhanced by adding silica nanofibers. As a result they can be used as high-performance and eco-friendly electrolytes in the production of all-solid, sustainable devices.