Lithium-rich layered oxides (LLOs) have attracted tremendous attention as promising high-energy cathode materials thanks to their superb capacity through additional anionic oxygen redox. The unique cationic superstructure ordering in the Li-rich domains is responsible for triggering the characteristic anionic oxygen redox; however, the aggregated Li-rich domains lead to excessive oxidation of lattice oxygen, resulting in irreversible oxygen release and structural breakdown. Here, we probe the chemical and structural evolution during the conventional synthesis of Co-free Li-rich cathodes in real time to understand the formation of the superstructure domains. Comprehensive examinations through a suite of advanced analysis tools reveal an overlooked role of lithium sources that manipulates the solid-state synthetic pathway, and thus dictates the evolution of the superstructure domain crystallography of the resulting Li-rich cathodes. We suggest that promoted synthetic reactions with the use of lithium hydroxide monohydrate render the formation of Li-rich domain-dispersed structure which enhances the electrochemical reversibility of LLO cathodes by mitigating the structural degradation from over-oxidation of lattice oxygen. The present study provides fundamental insights into regulating homogeneities in chemical and structural properties of synthetic intermediates upon calcination to achieve highly stable and reversible Li-rich cathodes towards broader market penetration.

中文翻译：

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揭示和调节富锂层状氧化物阴极中的超结构域分散以获得高稳定性和可逆性


富锂层状氧化物（LLO）作为有前途的高能阴极材料，由于其通过额外阴离子氧氧化还原的卓越能力而引起了极大的关注。富锂域中独特的阳离子超结构排序负责触发特征性阴离子氧氧化还原；然而，聚集的富锂域导致晶格氧过度氧化，导致不可逆的氧释放和结构破坏。在这里，我们实时探究无钴富锂正极的常规合成过程中的化学和结构演变，以了解超结构域的形成。通过一套先进的分析工具进行的全面检查揭示了锂源操纵固态合成途径的被忽视的作用，从而决定了所得富锂正极的超结构域晶体学的演变。我们建议，使用一水氢氧化锂促进合成反应，形成富锂域分散结构，通过减轻晶格氧过度氧化导致的结构降解，增强 LLO 阴极的电化学可逆性。本研究为调节合成中间体在煅烧时的化学和结构特性的均匀性提供了基本见解，以实现高度稳定和可逆的富锂正极，从而实现更广泛的市场渗透。