阴极
电化学
材料科学
氧化物
氧气
离子
电流密度
化学工程
钠
电极
化学
冶金
物理化学
有机化学
工程类
物理
量子力学
作者
Chang Su,Guoqiang Liu,Qiang Sun,Lei Wen,Zeyu Chen,Ming Zhao
出处
期刊:ACS applied energy materials
[American Chemical Society]
日期:2024-02-29
卷期号:7 (5): 1927-1937
标识
DOI:10.1021/acsaem.3c03039
摘要
The series P2-type Mn–Fe-based layered oxide materials (Na2/3MnxFe1–xO2) for sodium-ion batteries are regarded as potential commercial cathode materials due to their high specific capacity and low cost. However, the P2-type layered oxide cannot avoid some phase transformation during the charge–discharge process, which results in poor structural reversibility and low-capacity retention. Moreover, a high capacity usually means more insertion/extraction of Na+, which results in large changes in the lattice volume and poor cycling stability. Herein, a new strategy containing oxygen vacancies and Mg substitution is designed to obtain high-performance sodium storage of Mn–Fe-based layered oxide. The P′2-type Na0.67Mn0.85Fe0.1Mg0.05O2−δ (Ovs & Mg-sub) cathode material is synthesized by the above-mentioned dual-modification strategy. The effect of oxygen vacancies and Mg substitution on the structural evolution during the charge–discharge process is further investigated by in situ X-ray diffraction techniques. It demonstrates that Ovs & Mg-sub has reversible structural transformation and smaller lattice volume changes, thus further exhibiting prominent electrochemical properties. The initial discharge specific capacity reaches 190.2 mAh g–1 at a current density of 20 mA g–1 and remains at 152.9 mAh g–1 at a current density of 100 mA g–1 after 100 cycles. In addition, it has a superior rate capability of 88.9 mAh g–1 at a current density of 2000 mA g–1.
科研通智能强力驱动
Strongly Powered by AbleSci AI