美国阿贡国家实验室的Tongchao Liu小组取得一项新突破。他们的最新研究提出了，高机械化学稳定性富锂锰基氧化物的应变张力抑制相构建。该研究于2025年1月21日发表于国际一流学术期刊《美国化学会杂志》上。

研究人员表示，一种层状富锂锰基氧化物阴极，含有R3m（LiTMO₂, TM = Mn, Ni, Co）和C2/m（Li₂MnO₃）纳米畴，利用过渡金属和氧氧化还原产生可观的能量密度。然而，层状富锂氧化物固有的非均质性和独特的纳米畴氧化还原化学性质，将不可避免地导致其晶格应变和结构位移，这是传统掺杂或涂覆策略难以消除的，从而导致性能加快衰减。

在该研究中，研究团队在层状结构中加入了一种抑制应变的钙钛矿相，以有效地抑制锂离子不均匀提取过程中的位移和晶格中张力。设计的阴极的机械化学稳定性增强，有利于结构的持久性和氧氧化还原的可逆性，从而实现高的初始库仑效率和稳定的循环和电压分布。

他们的晶格工程方法缓解了非均质纳米畴之间的，非均质反应性所引起的应变和位移，促进了具有长寿命的先进正极材料发展。

附：英文原文

Title: Coherent Strain-Inhibiting Phase Construction of Lithium-Rich Manganese-Based Oxide Toward High Mechanochemical Stability

Author: Zhou Xu, Xingzhong Guo, Xuemei Zeng, Junxiang Liu, Jingran Yin, Minglu Ren, Junzhang Wang, Tengteng Qin, Zhizhen Zhang, Luxi Li, Khalil Amine, Yifei Yuan, Tongchao Liu

Issue&Volume: January 21, 2025

Abstract: A layered lithium-rich manganese-based oxide cathode, containing R3m (LiTMO2, TM = Mn, Ni, Co) and C2/m (Li2MnO3) nanodomains, utilizes both transition metals and oxygen redox to yield substantial energy density. However, the inherent heterogeneous nature and distinct nanodomain redox chemistries of layered lithium-rich oxides will inevitably cause pernicious lattice strain and structural displacement, which can hardly be eliminated by conventional doping or coating strategies and result in accelerated performance decay. Herein, we incorporate a strain-inhibiting perovskite phase coherently grown within the layered structure to effectively restrain the displacement and lattice strain during uneven Li-ion extraction. The enhanced mechanochemical stability of the designed cathode benefits the persistent structure and reversible oxygen redox, thereby achieving high initial Coulombic efficiency and stable cycling and voltage profiles. Our approach of lattice engineering alleviates the strain and displacement caused by inhomogeneous reactivity between heterogeneous nanodomains and promotes the development of advanced cathode materials with long durability.

DOI: 10.1021/jacs.4c11385

Source:https://pubs.acs.org/doi/abs/10.1021/jacs.4c11385