In Situ Constructed TiO 2 on Ti 3 C 2 ‐ MXene Cathode Enables Photo‐Assisted Zn‐Ion Hybrid Microsupercapacitors With High‐Energy Density

The design of novel photo‐assisted zinc‐ion hybrid microsupercapacitors (ZIH‐MSC) is regarded as an effective approach for storing solar energy and enhancing electrochemical energy storage. Herein, we develop a strategy for in situ constructed of TiO 2 nanoparticles on a Ti 3 C 2 ‐MXene cathode, which is assembled with zinc anode to form a photo‐assisted ZIH‐MSC device. In this device, the in situ‐constructed TiO 2 nanoparticles generate charge carriers under light irradiation, thereby accelerating electrochemical reactions. Moreover, the in situ‐constructed TiO 2 nanoparticles exhibit enhanced hydrophilicity, strengthening the interfacial interactions between the electrolyte and MXene electrode. Additionally, the in situ‐constructed TiO 2 nanoparticles function as a spacer to broaden the interlayer ionic transport pathways within MXene, thereby enhancing charge storage performance. Consequently, the designed photo‐assisted ZIH‐MSC device achieves a wide operating voltage (1.3 V) and high‐energy density (97 μWh cm −2 , 1 mA cm −2 ), representing a 20% increase in energy density compared to non‐photo‐assisted conditions (81 μWh cm −2 ). This work provides innovative insights for the development and application of high‐performance photo‐assisted energy storage devices.