Screen-Printable Hexagonal Boron Nitride Ionogel Electrolytes for Mechanically Deformable Solid-State Lithium-Ion Batteries

Ionogel electrolytes present several benefits for solid-state lithium-ion batteries including nonflammability, favorable electrochemical properties, and high thermal stability. However, limited processing methods are currently available for ionogel electrolytes, restricting their practical applications. Here, we present a screen-printable ionogel electrolyte formulation based on hexagonal boron nitride (hBN) nanoplatelets. To achieve screen-printable rheological properties, hBN nanoplatelets are mixed with an imidazolium ionic liquid in ethyl lactate. Following screen printing, the resulting spatially uniform and mechanically flexible hBN ionogel electrolytes achieve high room-temperature ionic conductivities >1 mS cm–1 and stiff mechanical moduli >1 MPa. These hBN ionogel electrolytes enable the fabrication of fully screen-printed lithium-ion batteries with high cycling stability, rate performance, and mechanical resilience against flexion and external forces, thus providing a robust energy storage solution that is compatible with scalable additive manufacturing.