Key Laboratory of Colloid and Interface Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering, Shandong University, Jinan, 250100, P. R. China.
College of Mechanical and Electronic Engineering, Shandong University of Science and Technology, Qingdao, 266590, P. R. China.
Angew Chem Int Ed Engl. 2023 Mar 27;62(14):e202214258. doi: 10.1002/anie.202214258. Epub 2022 Dec 22.
The applications of alloy-type anode materials for Na-ion batteries are always obstructed by enormous volume variation upon cycles. Here, K ions are introduced as an electrolyte additive to improve the electrochemical performance via electrostatic shielding, using Sn microparticles (μ-Sn) as a model. Theoretical calculations and experimental results indicate that K ions are not incorporated in the electrode, but accumulate on some sites. This accumulation slows down the local sodiation at the "hot spots", promotes the uniform sodiation and enhances the electrode stability. Therefore, the electrode maintains a high specific capacity of 565 mAh g after 3000 cycles at 2 A g , much better than the case without K . The electrode also remains an areal capacity of ≈3.5 mAh cm after 100 cycles. This method does not involve time-consuming preparation, sophisticated instruments and expensive reagents, exhibiting the promising potential for other anode materials.
钠离子电池的合金型阳极材料的应用由于循环过程中的巨大体积变化而受到阻碍。在这里，引入钾离子作为电解质添加剂，通过静电屏蔽作用来改善电化学性能，使用锡微颗粒（μ-Sn）作为模型。理论计算和实验结果表明，钾离子并未被嵌入电极中，而是在一些位置上积累。这种积累减缓了“热点”处的局部钠化过程，促进了均匀的钠化并增强了电极稳定性。因此，电极在 2 A/g 的电流密度下循环 3000 次后仍保持 565 mAh/g 的高比容量，明显优于不加钾的情况。电极在 100 次循环后仍保持约 3.5 mAh/cm 的面容量。该方法不涉及耗时的制备、复杂的仪器和昂贵的试剂，对于其他阳极材料表现出有前景的潜力。
