Anionic redox reaction (ARR) in lithium- and sodium-ion batteries is under hot discussion, mainly regarding how oxygen anion participates and to what extent oxygen can be reversibly oxidized and reduced. Here, a P3-type Na_0.6[Li_0.2Mn_0.8]O₂ with reversible capacity from pure ARR was studied. The interlayer O-O distance (peroxo-like O-O dimer, 2.506(3) Å), associated with oxidization of oxygen anions, was directly detected by using a neutron total scattering technique. Different from Li₂RuO₃ or Li₂IrO₃ with strong metal-oxygen (M-O) bonding, for P3-type Na_0.6[Li_0.2Mn_0.8]O₂ with relatively weak Mn-O covalent bonding, crystal structure factors might play an even more important role in stabilizing the oxidized species, as both Li and Mn ions are immobile in the structure and thus may inhibit the irreversible transformation of the oxidized species to O₂ gas.

锂离子电池和钠离子电池中的阴离子氧化还原反应（ARR）受到热议，主要涉及氧阴离子如何参与以及氧可逆氧化和还原的程度。在此，研究了纯ARR具有可逆容量的P3型Na _0.6 [Li _0.2 Mn _0.8 ] O ₂。通过使用中子全散射技术直接检测与氧阴离子的氧化有关的层间OO距离（类过氧化物的OO二聚体，2.506（3）Å）。选自Li不同₂的RuO ₃或Li ₂的IrO ₃具有较强的金属-氧（MO）键合，对于P3型的Na _0.6 [李_0.2锰_0.8具有相对较弱的Mn-O共价键的] O ₂，晶体结构因子可能在稳定氧化物种中起着更为重要的作用，因为Li和Mn离子均不固定在结构中，因此可以抑制氧化物种的不可逆转变到O ₂气。