Key Lab for Special Functional Materials of Ministry of Education, National & Local Joint Engineering Research Center for High-efficiency Display and Lighting Technology, School of Materials Science and Engineering, and Collaborative Innovation Center of Nano Functional Materials and Applications , Henan University , Kaifeng , 475004 , People's Republic of China.
J Am Chem Soc. 2019 Apr 17;141(15):6263-6270. doi: 10.1021/jacs.8b13568. Epub 2019 Apr 3.
The oxygen reduction reaction (ORR) in aprotic electrolyte is the essential reaction in metal-oxygen batteries. Capturing and shifting the absorbed metal superoxide intermediates/products from a cathode surface is a long-standing challenge to clarify the ORR mechanism, accelerate the ORR, and improve the stability and energy density of metal-oxygen batteries. Herein, a bioinspired pathway in which cathode solid catalysts and soluble anthraquinone (AQ) molecules initiate an "enzyme-coenzyme" cooperative catalysis mechanism is developed to greatly boost the ORR activity of solid catalysts over 10-fold, in which AQ acts as a scavenger to capture and shift the absorbed superoxide species from the cathode surface to the aprotic electrolyte. Taking the lithium-oxygen (Li-O) battery as a model system, the cell discharge ORR mechanism is well illustrated and capacities are significantly improved over 3 times in the presence of AQ molecules. This concept represents the first demonstration of stabilizing and solvating superoxide species to substantially accelerate ORR catalysis of solid catalysts and enhance the performance of metal-O batteries through biomimicking coenzyme-assisted reactions.
在非质子电解质中，氧气还原反应（ORR）是金属-氧电池的基本反应。将吸附的金属过氧化物中间体/产物从阴极表面捕获并转移是阐明 ORR 机理、加速 ORR 以及提高金属-氧电池的稳定性和能量密度的长期挑战。本文中，开发了一种受生物启发的途径，其中阴极固体催化剂和可溶性蒽醌（AQ）分子引发“酶-辅酶”协同催化机制，可使固体催化剂的 ORR 活性大大提高 10 倍以上，其中 AQ 作为清除剂从阴极表面捕获和转移吸附的超氧化物物种到非质子电解质中。以锂-氧（Li-O）电池为模型体系，很好地说明了电池的放电 ORR 机理，并且在存在 AQ 分子的情况下，容量显著提高了 3 倍以上。该概念代表了通过模拟辅酶辅助反应稳定和溶解超氧化物物种，从而显著加速固体催化剂的 ORR 催化并提高金属-O 电池性能的首例证明。
