Synthesis and Properties of a Photopatternable Lithium‐Ion Conducting Solid Electrolyte

One of the important considerations for the development of on‐chip batteries is the need to photopattern the solid electrolyte directly on electrodes. Herein, the photopatterning of a lithium‐ion conducting solid electrolyte is demonstrated by modifying a well‐known negative photoresist, SU‐8, with LiClO 4 . The resulting material exhibits a room temperature ionic conductivity of 52 µS cm −1 with a wide electrochemical window (>5 V). Half‐cell galvanostatic testing of 3 µm thin films spin‐coated on amorphous silicon validates its use for on‐chip energy‐storage applications. The modified SU‐8 possesses excellent mechanical integrity, is thermally stable up to 250 °C, and can be photopatterned with micrometer‐scale resolution. These results present a promising direction for the integration of electrochemical energy storage in microelectronics.