Nacre‐Inspired Composite Electrolytes for Load‐Bearing Solid‐State Lithium‐Metal Batteries

Abstract Solid‐state lithium‐metal batteries with solid electrolytes are promising for next‐generation energy‐storage devices. However, it remains challenging to develop solid electrolytes that are both mechanically robust and strong against external mechanical load, due to the brittleness of ceramic electrolytes and the softness of polymer electrolytes. Herein, a nacre‐inspired design of ceramic/polymer solid composite electrolytes with a “brick‐and‐mortar” microstructure is proposed. The nacre‐like ceramic/polymer electrolyte (NCPE) simultaneously possesses a much higher fracture strain (1.1%) than pure ceramic electrolytes (0.13%) and a much larger ultimate flexural modulus (7.8 GPa) than pure polymer electrolytes (20 MPa). The electrochemical performance of NCPE is also much better than pure ceramic or polymer electrolytes, especially under mechanical load. A 5 × 5 cm 2 pouch cell with LAGP/poly(ether‐acrylate) NCPE exhibits stable cycling with a capacity retention of 95.6% over 100 cycles at room temperature, even undergoes a large point load of 10 N. In contrast, cells based on pure ceramic and pure polymer electrolyte show poor cycle life. The NCPE provides a new design for solid composite electrolyte and opens up new possibilities for future solid‐state lithium‐metal batteries and structural energy storage.