Crystal Structures and Electrochemical Performance of Air-Stable Na2/3Ni1/3–xCuxMn2/3O2 in Sodium Cells,Chemistry of Materials

当前位置： X-MOL 学术 › Chem. Mater. › 论文详情

Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)

Crystal Structures and Electrochemical Performance of Air-Stable Na2/3Ni1/3–xCuxMn2/3O2 in Sodium Cells
Chemistry of Materials ( IF 7.2 ) Pub Date : 2017-02-08 00:00:00 , DOI: 10.1021/acs.chemmater.6b04769
Lituo Zheng ₁ , Jierui Li ₁ , M. N. Obrovac ₁

Affiliation

Sodium ion batteries have garnered significant research attention in recent years due to the rising demand for large-scale energy storage solutions as well as the high abundance of sodium. P2-type layered oxide materials have been identified as promising positive electrode materials for sodium ion batteries. Previously, P2–Na_2/3Ni_1/3Mn_2/3O₂ was shown to have a high operating voltage and high capacity but suffers from a step-like voltage curve and capacity loss during cycling, potentially due to its P2–O2 transition at high voltages. One strategy to improve cycling performance has been to dope Ni²⁺ with other 2+ cations, such as Zn²⁺ or Mg²⁺, which improved capacity retention but significantly decreases reversible capacity, since these ions were not electrochemically active. Since Cu²⁺ has been shown to be electrochemically active, we replaced Ni²⁺ with Cu²⁺, resulting in air-stable Na_2/3Ni_1/3–xCu_xMn_2/3O₂ (0 ≤ x ≤ 1/3). Both Ni²⁺/Ni⁴⁺ and Cu²⁺/Cu³⁺ participate in the redox reaction during cycling, capacity retention was greatly improved, and phase changes were suppressed during cycling without sacrificing much capacity. The material retains a P2/OP4 structure even when cycled to high voltages. The doping strategy is a promising approach for the future development of positive electrode materials for sodium ion batteries.

中文翻译：

钠电池中空气稳定的Na _2/3 Ni _{1 / 3– x} Cu _x Mn _2/3 O _2的晶体结构和电化学性能

近年来，由于对大型储能解决方案的需求不断增长以及钠的含量很高，钠离子电池已引起了广泛的研究关注。P2型层状氧化物材料已被确定为有前途的钠离子电池正极材料。以前，P2-Na _2/3 Ni _1/3 Mn _2/3 O ₂具有较高的工作电压和高容量，但由于其P2-氧气在高压下转变。改善循环性能的一种策略是将Ni ²⁺掺入其他2+阳离子，例如Zn ²⁺或Mg ²⁺，因为这些离子没有电化学活性，因此提高了容量保持能力，但显着降低了可逆容量。由于铜²⁺已被证明是电化学活性的，我们所取代的Ni ²⁺与铜²⁺，产生空气稳定的Na _2/3的Ni _{1 / 3- X}的Cu _X的Mn _2/3 Ø ₂（0≤ X ≤ 1/3）。Ni ²⁺ / Ni ⁴⁺和Cu ²⁺ / Cu ³⁺参与循环过程中的氧化还原反应，容量保持能力大大提高，并且在循环过程中抑制了相变而没有牺牲太多的容量。该材料即使在循环至高电压时仍保持P2 / OP4结构。掺杂策略是钠离子电池正极材料未来发展的一种有前途的方法。

更新日期：2017-02-08

点击分享查看原文

点击收藏

阅读更多本刊新发论文本刊介绍/投稿指南