Fu Fang, Liu Xiang, Fu Xiaoguang, Chen Hongwei, Huang Ling, Fan Jingjing, Le Jiabo, Wang Qiuxiang, Yang Weihua, Ren Yang, Amine Khalil, Sun Shi-Gang, Xu Gui-Liang
College of Materials Science and Engineering, Huaqiao University, Xiamen, 361021, China.
Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, IL, 60439, United States.
Nat Commun. 2022 May 20;13(1):2826. doi: 10.1038/s41467-022-30113-0.
P2-type sodium manganese-rich layered oxides are promising cathode candidates for sodium-based batteries because of their appealing cost-effective and capacity features. However, the structural distortion and cationic rearrangement induced by irreversible phase transition and anionic redox reaction at high cell voltage (i.e., >4.0 V) cause sluggish Na-ion kinetics and severe capacity decay. To circumvent these issues, here, we report a strategy to develop P2-type layered cathodes via configurational entropy and ion-diffusion structural tuning. In situ synchrotron X-ray diffraction combined with electrochemical kinetic tests and microstructural characterizations reveal that the entropy-tuned NaMnNiCuMgTiO (CuMgTi-571) cathode possesses more {010} active facet, improved structural and thermal stability and faster anionic redox kinetics compared to NaMnNiO. When tested in combination with a Na metal anode and a non-aqueous NaClO-based electrolyte solution in coin cell configuration, the CuMgTi-571-based positive electrode enables an 87% capacity retention after 500 cycles at 120 mA g and about 75% capacity retention after 2000 cycles at 1.2 A g.
P2型富钠锰层状氧化物因其具有吸引人的成本效益和容量特性，是钠基电池很有前景的阴极候选材料。然而，在高电池电压（即>4.0 V）下由不可逆相变和阴离子氧化还原反应引起的结构畸变和阳离子重排会导致钠离子动力学迟缓以及严重的容量衰减。为了规避这些问题，在此我们报告一种通过构型熵和离子扩散结构调控来开发P2型层状阴极的策略。原位同步加速器X射线衍射结合电化学动力学测试和微观结构表征表明，与NaMnNiO相比，熵调谐的NaMnNiCuMgTiO（CuMgTi-571）阴极具有更多的{010}活性面、更高的结构和热稳定性以及更快的阴离子氧化还原动力学。当在硬币电池配置中与钠金属阳极和基于非水NaClO的电解质溶液组合测试时，基于CuMgTi-571的正极在120 mA g下500次循环后容量保持率为87%，在1.2 A g下2000次循环后容量保持率约为75%。
