Tao Yinglei, Fan Xiaoli, Yu Xingyu, Gong Ke, Xia Yujiao, Gong Hao, Chen Haixia, Huang Xianli, Zhang Aidi, Wang Tao, He Jianping
College of Materials Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing, 210016, P. R. China.
School of Materials Science and Engineering, Nanjing Institute of Technology, Nanjing, 211167, P. R. China.
Small. 2024 Nov;20(46):e2403683. doi: 10.1002/smll.202403683. Epub 2024 Aug 7.
Li-O batteries (LOBs) have sparked significant interest due to their fascinating high theoretical energy density. However, the large overpotential for the formation and oxidation of LiO during charge and discharge process seriously hinders the further development and application of LOBs. In this work, metal-organic frameworks (MOFs) with different metal clusters (Fe, Ti, Zr) are successfully synthesized, and they are employed as the photoelectrodes for the photo-assisted LOBs. The special dual excitation pathways of Fe-MOF under illumination and the superior separation efficiency of photocarriers, which significantly enhance the activation of O/LiO, improving the catalytic activity of oxygen reduction reaction and oxygen evolution reaction. Moreover, compared to traditional inorganic semiconductor crystals, Fe-MOF exhibits large specific surface area and excellent O adsorption ability. Therefore, the LOB with Fe-MOF as the cathode exhibits large specific capacity, ultralow charge/discharge overpotential of 0.22 V at 0.05 mA cm and excellent stability of 195 cycles under illumination. This study provides an environmentally friendly and highly efficient photocatalyst for LOBs, and a new strategy for designing photoelectrodes.
锂-氧电池（LOBs）因其迷人的高理论能量密度而引发了极大的关注。然而，在充放电过程中LiO形成和氧化的大过电位严重阻碍了LOBs的进一步发展和应用。在这项工作中，成功合成了具有不同金属簇（Fe、Ti、Zr）的金属有机框架（MOFs），并将其用作光辅助LOBs的光电极。Fe-MOF在光照下的特殊双激发途径以及光载流子的优异分离效率，显著增强了O/LiO的活化，提高了氧还原反应和析氧反应的催化活性。此外，与传统无机半导体晶体相比，Fe-MOF具有大的比表面积和优异的O吸附能力。因此，以Fe-MOF为阴极的LOB表现出大的比容量、在0.05 mA cm下0.22 V的超低充放电过电位以及在光照下195次循环的优异稳定性。本研究为LOBs提供了一种环境友好且高效的光催化剂，并为设计光电极提供了一种新策略。
