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 LiClO₄ . 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.