Li-rich Mn-based oxide cathodes for next generation high-energy-density batteries are unprecedentedly enticing; however, its implementation has been largely plagued by capacity fading and potential decline, mainly associated with the irreversible lattice oxygen redox and structure rearrangements. Hereby, electrochemically stable Li-rich Mn-based oxide cathode is successfully designed by manipulating molecular polarity within host structure through the introduction of Se. Notably, the restructured electronic distribution around lattice oxygen is aroused from weak electronegativity of Se in the bulk. It is beneficial for enhancing the π-type orbital hybridization between O 2p and Mn 3d(t_2g) due to the lowered energy level of O 2p states, resulting in the mitigation of lattice oxygen loss, which is strongly validated by ex-situ soft/hard X-ray absorption spectroscopy coupled with density functional theory calculations. Concomitantly, reactive oxygen species is deactivated with anti-aging effects in the primary/second particle sub-surface, considerably suppressing the S_N2 attack related to electrolyte decomposition and subsequent transition metals dissolution to render a well-knit cathode electrolyte interface, intensively verified by time-off light secondary-ion mass spectrometry. Greatly, the as-designed Se-LRM delivers excellent long cycling stability after 400 loops with only a 0.029% capacity fading and 1.37 mV potential decline per cycle. Given this, this elaborate work might inaugurate a potential avenue for rationally tuning the structure/interface evolution towards advanced electrodes in lithium-ion batteries.

用于下一代高能量密度电池的富锂锰基氧化物正极具有前所未有的吸引力；然而，其实施在很大程度上受到容量衰减和潜在下降的困扰，主要与不可逆的晶格氧氧化还原和结构重排有关。因此，通过引入Se来控制主体结构内的分子极性，成功地设计了电化学稳定的富锂锰基氧化物正极。值得注意的是，晶格氧周围的重构电子分布是由体中硒的弱电负性引起的。由于O 2p的能级降低，有利于增强O 2p和Mn 3d(t _{2g ) 之间的}π型轨道杂化状态，导致晶格氧损失的减轻，这通过非原位软/硬 X 射线吸收光谱结合密度泛函理论计算得到了强有力的验证。同时，活性氧物质在初级/次级粒子亚表面中具有抗老化作用而失活，显着抑制了S _N 2与电解质分解和随后的过渡金属溶解相关的攻击，以呈现紧密结合的阴极电解质界面，并通过延时光二次离子质谱法进行了深入验证。重要的是，所设计的 Se-LRM 在 400 次循环后具有出色的长循环稳定性，每个循环的容量衰减仅为 0.029%，电位下降 1.37 mV。鉴于此，这项精心设计的工作可能为合理调整锂离子电池中先进电极的结构/界面演变开辟了一条潜在途径。