At the cathode of a Li–O₂ battery, O₂ is reduced to Li₂O₂ on discharge, the process being reversed on charge. Li₂O₂ is an insulating and insoluble solid, leading ultimately to low rates, low capacities and early cell death if formed on the cathode surface. Here we show that when using dual mediators, 2,5-Di-tert-butyl-1,4-benzoquinone [DBBQ] on discharge and 2,2,6,6-tetramethyl-1-piperidinyloxy [TEMPO] on charge, the electrochemistry at the cathode surface is decoupled from Li₂O₂ formation/decomposition in solution. Capacities of 2 mAh cm_areal⁻² at 1 mA cm_areal⁻² with low polarization on charge/discharge are demonstrated, and up to 40 mAh cm_areal⁻² at rates ≫1 mA cm_areal⁻² are anticipated if suitable gas diffusion electrodes can be devised. One of the major barriers to the progress of Li–O₂ cells is decomposition of the carbon cathode. By forming/decomposing Li₂O₂ in solution and avoiding high charge potentials, the carbon instability is significantly mitigated (<0.008% decomposition per cycle compared with 0.12% without mediators).

在Li–O ₂电池的阴极，放电时O ₂还原为Li ₂ O ₂，充电过程相反。Li ₂ O ₂是一种绝缘且不可溶的固体，如果在阴极表面形成，最终会导致低倍率，低容量和早期电池死亡。在这里，我们显示当使用双重介体时，放电时使用2,5-二叔丁基-1,4-苯醌[DBBQ]，而充电时使用2,2,6,6-四甲基-1-哌啶基氧基[TEMPO]，阴极表面的电化学与溶液中Li ₂ O _2的形成/分解解耦。1 mA cm_面积^-2时2 mAh cm_面积^-2的容量与电荷低的偏振/放电证实的，和最多40毫安厘米_分布区^-2，速率» 1毫安厘米_面积^-2预期如果合适的气体扩散电极可以设计。Li–O ₂电池发展的主要障碍之一是碳阴极的分解。通过在溶液中形成/分解Li ₂ O ₂并避免高电荷电位，碳的不稳定性得到显着缓解（每个循环的分解<0.008％，相比之下，没有介体的分解为0.12％）。