Wang Haoji, Gao Jinqiang, Mei Yu, Ni Lianshan, He Yi, Hong Ningyun, Huang Jiangnan, Deng Wentao, Zou Guoqiang, Hou Hongshuai, Liu Tongchao, Liang Chaoping, Ji Xiaobo, Amine Khalil
College of Chemistry and Chemical Engineering, Central South University, Changsha, 410083, China.
Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, IL-60439, USA.
Angew Chem Int Ed Engl. 2025 Feb 3;64(6):e202418605. doi: 10.1002/anie.202418605. Epub 2024 Dec 27.
Oxygen redox chemistries at high voltage have materialized as a revolutionary paradigm for cathodes with high-energy density; however, they are plagued by the challenges of labile oxygen loss and rapid degradations upon cycling, even after concerted endeavors from the research community. Here we propose a multi-concentration stratagem propelled by entropy reinforcement to enhance the electronic structure disorder (ESD) at high desodiation states for impeding undesired oxygen mobility and ensuring controlled oxygen activity, elucidated by density functional theory calculations. The increased disorder strengthens the reversible electrochemistry of lattice oxygen redox, leading to effectively suppressed P-O structural evolution and highly stable localized TMO octahedral environments, as demonstrated by soft/hard X-ray absorption spectroscopy. Furthermore, through a comparative analysis of sodium-layered cathodes with different configuration entropy, we reveal that a high-entropy state induced by cationic disordering has the capacity to perturb cationic redox boundaries, significantly restraining the formation of detrimental O'3 phases. As a consequence, the high-voltage cycling stability has been greatly upgraded, up to 4.4 V versus Na/Na, with an impressive 90.1 % capacity retention at 1 C over 100 cycles and 76.1 % capacity retention at 2 C over 300 cycles. The resilient oxygen redox, enabled through the control of ESD, broadens the horizons for entropy engineering and lays the foundation for advancements in high-energy, long-cycling, and safe batteries.
高压下的氧氧化还原化学已成为高能量密度阴极的一种革命性范式；然而，即使在研究界共同努力之后，它们仍面临着不稳定的氧损失和循环过程中快速降解的挑战。在此，我们提出一种由熵增强推动的多浓度策略，以增强高脱钠状态下的电子结构无序性（ESD），从而阻碍不期望的氧迁移并确保可控的氧活性，这一策略通过密度泛函理论计算得以阐明。如软/硬X射线吸收光谱所示，增加的无序性增强了晶格氧氧化还原的可逆电化学性能，有效抑制了P-O结构演变，并实现了高度稳定的局部TMO八面体环境。此外，通过对具有不同构型熵的钠层状阴极进行对比分析，我们发现阳离子无序诱导的高熵状态有能力扰乱阳离子氧化还原边界，显著抑制有害O'3相的形成。结果，高压循环稳定性得到了极大提升，相对于Na/Na高达4.4 V，在1 C下100次循环时容量保持率高达90.1%，在2 C下300次循环时容量保持率为76.1%。通过控制ESD实现的弹性氧氧化还原拓宽了熵工程的视野，为高能、长循环和安全电池的发展奠定了基础。
