Shen Xiaoxiao, Zhang Shuaishuai, Wu Yuping, Chen Yuhui
State Key Laboratory of Materials-oriented Chemical Engineering, School of Energy Science and Engineering, Nanjing Tech University, Nanjing, Jiangsu, 211816, P.R. China.
ChemSusChem. 2019 Jan 10;12(1):104-114. doi: 10.1002/cssc.201802007. Epub 2019 Jan 9.
Li-O batteries have a high theoretical specific energy, 3500 Wh kg ; however, its practical capacity is far below this value and limited by the passivation with the insulating discharge product Li O . The nonconductive nature of Li O also impedes the charging process, leading to a low coulombic efficiency and high overpotential on charge even at a moderate rate. To address these challenges, redox mediators could be used both during discharge and charge to transfer electrons between O /electrode surface or Li O /electrode surface to overcome the passivation of Li O , which would facilitate the discharge and charge process. The capacity and current density were significantly improved using the redox mediators, thus representing a promising strategy to achieve a high energy density for Li-O batteries.
锂氧电池具有较高的理论比能量，为3500 Wh kg；然而，其实际容量远低于该值，并受到与绝缘放电产物Li₂O钝化的限制。Li₂O的非导电性质也阻碍了充电过程，导致库仑效率低，即使在中等速率下充电时过电位也很高。为应对这些挑战，氧化还原介质可在放电和充电过程中使用，以在O₂/电极表面或Li₂O/电极表面之间转移电子，从而克服Li₂O的钝化，这将促进放电和充电过程。使用氧化还原介质后，容量和电流密度显著提高，因此是实现锂氧电池高能量密度的一种有前景的策略。
