Fluorine-Rich Oxyfluoride Spinel-like Li 1.25 Ni 0.625 Mn 1.125 O 3 F Utilizing Redox-Active Ni and Mn for High Capacity and Improved Cyclability
Fluorine-Rich Oxyfluoride Spinel-like Li 1.25 Ni 0.625 Mn 1.125 O 3 F Utilizing Redox-Active Ni and Mn for High Capacity and Improved Cyclability
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富氟氟氧化物尖晶石状 Li 1.25 Ni 0.625 Mn 1.125 O 3 F 利用氧化还原活性 Ni 和 Mn 实现高容量并改善循环性能
DOI：
10.1021/acsmaterialslett.2c00973
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发表时间：
2023
影响因子：
11.4
通讯作者：
Cai H
中科院分区：
文献类型：
--
作者：
Cai H
扩大可达容量和可循环性是锂离子电池阴极材料的核心兴趣。在这里，我们报告了一个新的尖晶石状Li1.25Ni0.625Mn1.125O3F（Fd 3 m）氟氧化物的成功合成具有显着的阳离子紊乱，其特征在于结合X射线和中子衍射数据的改进。Li1.25Ni0.625Mn1.125O3F利用Ni和Mn的氧化还原反应，获得225的容量（即，1.46 Li+容量）和285 mAh g-1（即，1.85 Li+容量），通过将额外的Li+嵌入晶格中。此外，与先前报道的锂过渡金属无序岩盐或尖晶石状氟氧化物相比，Li1.25Ni0.625Mn1.125O3F显示出显著改善的循环稳定性。在不同的充电/放电状态下的样品的非原位组成，结构和光谱分析证实了单相嵌入反应和循环过程中的高结构完整性。
Extending the accessible capacity and cyclability is of central interest for cathode materials for Li-ion batteries. Here, we report the successful synthesis of a new spinel-like Li1.25Ni0.625Mn1.125O3F (Fd3m) oxyfluoride with significant cation disorder characterized by combined refinement of X-ray and neutron diffraction data. Li1.25Ni0.625Mn1.125O3F utilizes redox reactions of both Ni and Mn, accessing capacities of 225 (i.e., 1.46 Li+capacity) and 285 mAh g–1(i.e., 1.85 Li+capacity) at 25 and 40 °C, respectively, through intercalation of additional Li+into the lattice. Moreover, compared to lithium transition metal disordered rocksalt or spinel-like oxyfluorides previously reported, Li1.25Ni0.625Mn1.125O3F shows significantly improved cycling stability. Ex situ compositional, structural, and spectroscopic analyses of samples at different states of charge/discharge confirm a single-phase intercalation reaction and high structural integrity over cycling.