Realizing High Capacity and Zero Strain in Layered Oxide Cathodes via Lithium Dual-Site Substitution for Sodium-Ion Batteries.
Realizing High Capacity and Zero Strain in Layered Oxide Cathodes via Lithium Dual-Site Substitution for Sodium-Ion Batteries.
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DOI：
10.1021/jacs.3c00117
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发表时间：
2023-04
影响因子：
15
通讯作者：
Zhonghan Wu;Youxuan Ni;Sha Tan;E. Hu;Lunhua He;Jiuding Liu;Machuan Hou;Peixin Jiao;Kai Zhang;F. Cheng;Jun Chen
中科院分区：
文献类型：
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作者：
Zhonghan Wu;Youxuan Ni;Sha Tan;E. Hu;Lunhua He;Jiuding Liu;Machuan Hou;Peixin Jiao;Kai Zhang;F. Cheng;Jun Chen
钠离子电池作为一种电化学储能技术得到了前所未有的关注，但在动态(去)盐化过程中如何设计出高能量密度、低结构应变的正极材料仍然是一项具有挑战性的工作。在这里，我们报道了一种P2层锂双位取代的Na0.7Li0.03[Mg0.15Li0.07Mn0.75]O2(NMLMO)正极材料，其中Li离子同时占据了过渡金属(TM)和碱金属(AM)位。理论计算和实验表征相结合的结果表明，LITM创建了Na-O-Li电子组态，以提高氧阴离子氧化还原的容量，而LiAM则作为LiO6棱柱，通过抑制有害的相变来稳定层状结构。结果表明，NMLMO具有266mAHg-1的高比容量，同时在1.5-4.6V的宽电压范围内表现出近零应变特性。我们的发现突出了双位替代的有效方法，以打破先进充电电池正极材料的容量稳定性权衡。
Sodium-ion batteries have garnered unprecedented attention as an electrochemical energy storage technology, but it remains challenging to design high-energy-density cathode materials with low structural strain during the dynamic (de)sodiation processes. Herein, we report a P2-layered lithium dual-site-substituted Na0.7Li0.03[Mg0.15Li0.07Mn0.75]O2 (NMLMO) cathode material, in which Li ions occupy both transition-metal (TM) and alkali-metal (AM) sites. The combination of theoretical calculations and experimental characterizations reveals that LiTM creates Na-O-Li electronic configurations to boost the capacity derived from the oxygen anionic redox, while LiAM serves as LiO6 prismatic pillars to stabilize the layered structure through suppressing the detrimental phase transitions. As a result, NMLMO delivers a high specific capacity of 266 mAh g-1 and simultaneously exhibits the nearly zero-strain characteristic within a wide voltage range of 1.5-4.6 V. Our findings highlight the effective way of dual-site substitution to break the capacity-stability trade-off in cathode materials for advanced rechargeable batteries.