Hou Chen, Han Jiuhui, Liu Pan, Huang Gang, Chen Mingwei
Shanghai Key Laboratory of Advanced High Temperature Materials and Precision Forming and State Key Laboratory of Metal Matrix Composites, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, People's Republic of China.
Advanced Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan.
Nano Lett. 2020 Mar 11;20(3):2183-2190. doi: 10.1021/acs.nanolett.0c00357. Epub 2020 Feb 24.
The sluggish cathodic kinetics and lower energy efficiency, associated with solid and insulating discharge products of LiO, are the key factors that prevent the practical implementation of Li-O batteries (LOBs). Here we demonstrate that the combination of the solid catalyst (RuO) and soluble redox mediator tetrathiafulvalene (TTF) exhibits a synergetic effect in improving the cathodic kinetics and energy efficiency of LOBs by reducing both charge and discharge overpotentials. Operando electron microscopy observations and electrochemical measurements reveal that RuO not only exhibits bifunctional catalysis for Li-O reactions but also benefits the catalytic efficiency of TTF. Meanwhile, TTF plays an important role in activating the LiO passivated RuO catalysts and in helping RuO effectively oxidize the discharge products during charging. The synergetic effect of solid and liquid catalysts, beyond traditional bifunctional catalysis, obviously increases the cathodic kinetics and round-trip energy efficiency of LOBs.
与LiO的固体绝缘放电产物相关的缓慢阴极动力学和较低的能量效率，是阻碍锂氧电池（LOBs）实际应用的关键因素。在此，我们证明了固体催化剂（RuO）和可溶性氧化还原介质四硫富瓦烯（TTF）的组合通过降低充电和放电过电位，在改善LOBs的阴极动力学和能量效率方面表现出协同效应。原位电子显微镜观察和电化学测量表明，RuO不仅对Li-O反应具有双功能催化作用，而且有利于提高TTF的催化效率。同时，TTF在活化被LiO钝化的RuO催化剂以及帮助RuO在充电过程中有效氧化放电产物方面发挥着重要作用。固体和液体催化剂的协同效应超越了传统的双功能催化，显著提高了LOBs的阴极动力学和往返能量效率。
