Synchronous Light Harvesting and Energy Storing Organic Cathode Material 1,4-Dihydroxyanthraquinone for Lithium-Ion Batteries

The electrode materials for lithium-ion batteries which offer integrated conversion of light and storage of electricity are auspicious for compact and stand-alone energy systems. Herein, coin-cell lithium batteries based on organic compound 1,4-dihydroxyanthraquinone coupling porous carbon derived from MOFs (1,4DHAQ&ZIF-8C) are demonstrated. The proposed material simultaneously acts as lithium storing and photoactive electrode. Along with the electrochemical lithium-ion reactivity, 1,4DHAQ&ZIF-8C offers notable photoelectric properties, its specific capacity increases to 285mAh g-1 (1.58 times of the specific capacity without light) when illuminated, and the lithium-ion mobility improves to 0.313cm2 s-1 (up by 55%), meanwhile its charge transfer resistance decreases to 95.6Ω (down to 39%). Moreover, theoretical excited state analysis and microsecond measurements reveal the existence states of photogenerated carriers, demonstrating obvious intramolecular charge transfer and nanosecond-scale exciton lifetime (∼5ns). Our findings suggest valuable directions to advance the current strategies for the assembly of efficient photo-rechargeable lithium-ion batteries.