Integrating P2 into O′3 toward a robust Mn-Based layered cathode for sodium-ion batteries
Integrating P2 into O′3 toward a robust Mn-Based layered cathode for sodium-ion batteries
复制标题
将 P2 集成到 O-3 中，形成用于钠离子电池的坚固的锰基层状阴极
DOI：
10.1039/d0ta08383f
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发表时间：
2020-12-07
影响因子：
11.9
通讯作者：
Zhou, Haoshen
中科院分区：
文献类型：
--
作者：
Liu, Zhaoguo;Jiang, Kezhu;Zhou, Haoshen
钠离子电池锰基层状正极材料以其高容量、高性价比等优点备受关注。然而，在钠离子的提取和插入过程中，材料存在动力学迟缓和体积变化剧烈的问题，从而导致倍率性能较差，循环衰减较快。因此，提出了一种将结构稳定的P2集成到O‘3相中的策略，这不仅可以缓冲剧烈的晶格应变，而且可以增强Na-离子的扩散。P2/O‘3双相NaMn0.89Cu0.08Sb0.03O2正极具有204 mA h g(-1)的高可逆容量，150次循环后容量保持率高达80%，2C倍率下的容量为120 mA h g(-1)，与O’3NaMnO2形成鲜明对比。结果表明，P2掺杂后，样品的体积变化量和晶格参数c分别由原始的O‘3NaMnO2的27.04%和23.39%降低到10.5%和3.3%，Na-离子扩散系数从原始O’3NaMnO2的10(-12)增加到P2/O‘3两相的10(-11)。研究结果突出了复合电极的重要性和优越性，为高性能钠离子电池的合理设计提供了新的见解。
Manganese-based layered cathode materials for sodium-ion batteries are attractive on account of the superiorities of high capacity and cost effectiveness. Nevertheless, the materials suffer from sluggish kinetics and drastic volume changes during the extraction and insertion of Na ions, thereby resulting in inferior rate capability and rapid cycling decay. Herein, a strategy of integrating structurally stable P2 into the O ' 3 phase for robust Mn-based layered oxides is proposed, which not only buffers the drastic lattice strain, but also enhances Na-ion diffusion. The P2/O ' 3-biphasic NaMn0.89Cu0.08Sb0.03O2 cathode provides a high reversible capacity of 204 mA h g(-1), an admirable capacity retention of 80% after 150 cycles and a superior rate capability with 120 mA h g(-1) capacity at 2C rate, in stark contrast to O ' 3 NaMnO2. The results show that the volume change and lattice parameter c have been respectively reduced to 10.5% and 3.3% after P2 integration, compared with 27.04% and 23.39% for the original O ' 3 NaMnO2, and the Na-ion diffusion coefficient has been evidently increased from 10(-12) in the pristine O ' 3 NaMnO2 to 10(-11) in the P2/O ' 3 biphase. The findings highlight the significance and superiority of the composite electrode and provide new insights for the rational design of high-performance sodium-ion batteries.