In Li-O2 batteries (LOBs), the electron transfer between triplet O2 and singlet Li2O2 possesses a spin-dependent character but is still neglected, while the spin-conserved electron transfer without losing phase information should guarantee fast kinetics and reduced energy barriers. Here, we provide a paradigm of spin-selective catalysis for LOB that the ferromagnetic quantum spin exchange interactions between Pt and Fe atoms in fully-exposed PtFe clusters filter directional e-spins for spin-conserved electron transfer at Fe-Fe sites. The kinetics of O2/Li2O2 redox reaction is markedly accelerated as predicted by theoretical calculations, showing dramatically decreased relaxation time of the rate determining step for more than one order of magnitude, compared with the Fe clusters without spin-selective behavior. In consequence, the assembled LOB provides ultrahigh energy conversion efficiency of 89.6% at 100 mA g-1 under a discharge-charge overpotential of only 0.32 V. This work provides new insights into the spin-dependent mechanisms of O2/Li2O2 redox reaction, and the strategy of constructing spin catalysts at atomic level.

中文翻译：

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完全暴露的 PtFe 簇中的自旋选择性通道可实现 Li-O2 电池的快速阴极动力学


在 Li-O2 电池 （LOB） 中，三重态 O2 和单重态 Li2O2 之间的电子转移具有自旋依赖性特性，但仍被忽视，而不丢失相信息且自旋守恒的电子转移应保证快速动力学和减少能量势垒。在这里，我们提供了一种 LOB 自旋选择性催化的范例，即完全暴露的 PtFe 簇中 Pt 和 Fe 原子之间的铁磁量子自旋交换相互作用过滤定向 e-自旋，以便在 Fe-Fe 位点进行自旋守恒电子转移。正如理论计算预测的那样，O2/Li2O2 氧化还原反应的动力学显着加速，与没有自旋选择性行为的 Fe 团簇相比，速率确定步骤的弛豫时间显着缩短了一个数量级以上。因此，组装的 LOB 在仅 0.32 V 的放电-充电过电位下，在 100 mA g-1 时可提供 89.6% 的超高能量转换效率。这项工作为 O2/Li2O2 氧化还原反应的自旋依赖性机制以及在原子水平构建自旋催化剂的策略提供了新的见解。