电化学
阴极
电解质
电池(电)
阳极
材料科学
容量损失
相(物质)
氧化物
化学工程
钠离子电池
电化学窗口
金属
电极
分析化学(期刊)
化学
法拉第效率
冶金
物理化学
离子电导率
物理
工程类
功率(物理)
有机化学
量子力学
色谱法
作者
Björn Pohle,Mikhail V. Gorbunov,Qiongqiong Lu,Amin Bahrami,Kornelius Nielsch,Daria Mikhailova
出处
期刊:Energies
[Multidisciplinary Digital Publishing Institute]
日期:2022-05-05
卷期号:15 (9): 3371-3371
被引量:6
摘要
Layered Na0.8Co0.8Ti0.2O2 oxide crystallizes in the β-RbScO2 structure type (P2 modification) with Co(III) and Ti(IV) cations sharing the same crystallographic site in the metal-oxygen layers. It was synthesized as a single-phase material and characterized as a cathode in Na- and Na-ion batteries. A reversible capacity of about 110 mA h g−1 was obtained during cycling between 4.2 and 1.8 V vs. Na+/Na with a 0.1 C current density. This potential window corresponds to minor structural changes during (de)sodiation, evaluated from operando XRD analysis. This finding is in contrast to Ti-free NaxCoO2 materials showing a multi-step reaction mechanism, thus identifying Ti as a structure stabilizer, similar to other layered O3- and P2-NaxCo1−yTiyO2 oxides. However, charging the battery with the Na0.8Co0.8Ti0.2O2 cathode above 4.2 V results in the reversible formation of a O2-phase, while discharging below 1.5 V leads to the appearance of a second P2-layered phase with a larger unit cell, which disappears completely during subsequent battery charge. Extension of the potential window to higher or lower potentials beyond the 4.2–1.8 V range leads to a faster deterioration of the electrochemical performance. After 100 charging-discharging cycles between 4.2 and 1.8 V, the battery showed a capacity loss of about 20% in a conventional carbonate-based electrolyte. In order to improve the cycling stability, different approaches including protective coatings or layers of the cathodic and anodic surface were applied and compared with each other.
科研通智能强力驱动
Strongly Powered by AbleSci AI