Wang Xianchao, Zhang Xuan, Chen Ye, Dong Jinqiao, Zhao Jing
Key Laboratory of Superlight Materials and Surface Technology of Ministry of Education, College of Materials Science and Chemical Engineering, Harbin Engineering University, Harbin, 150001, China.
School of Chemistry and Chemical Engineering, Frontiers Science Center for Transformative Molecules and State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, Shanghai, 200240, China.
Small. 2024 Jul;20(30):e2312130. doi: 10.1002/smll.202312130. Epub 2024 Feb 26.
The principal challenges faced by sodium-ion batteries (SIBs) and potassium-ion batteries (KIBs) revolve around identifying suitable host materials capable of accommodating metal ions with larger dimensions and addressing the issue of sluggish chemical kinetics. Herein, a MoSe/CrSe heterojunction uniformly embedded is fabricated in nitrogen-doped hollow carbon nanospheres (MoSe/CrSe@N-HCSs) as an electrode material for SIBs and KIBs. CrSe exhibits spontaneous antiparallel alignment of magnetic moments. Mo doping is employed to regulate the electron spin states of CrSe. Moreover, the MoSe and CrSe heterojunctions induce a lattice mismatch at the heterostructure interface, resulting in spin-polarized states or localized magnetic moments at the interface, potentially contributing to spin-polarized surface capacitance. MoSe/CrSe@N-HCSs demonstrate a high capacity of 498 mAh g at 0.1 A g with good cycling stability (capacity of 405 mAh g and a coulombic efficiency of 99.8% after 1000 cycles). Additionally, density functional theory (DFT) calculations simulate the accumulation of spin-polarized charges at the MoSe/CrSe@N-HCSs heterojunction interface, dependent on the surface electron density of the antiferromagnetic CrSe and the surface spin polarization near the Fermi level. After regulating the electron spin states through Mo-doping, the band gap of the material decreases. These significant findings provide novel insights into the design and synthesis of electrode materials with exceptional performance characteristics for batteries.
钠离子电池（SIBs）和钾离子电池（KIBs）面临的主要挑战围绕着识别能够容纳尺寸更大的金属离子的合适主体材料以及解决化学动力学缓慢的问题。在此，一种均匀嵌入的MoSe/CrSe异质结被制备在氮掺杂空心碳纳米球（MoSe/CrSe@N-HCSs）中，作为SIBs和KIBs的电极材料。CrSe表现出自发的磁矩反平行排列。采用Mo掺杂来调节CrSe的电子自旋态。此外，MoSe和CrSe异质结在异质结构界面处引起晶格失配，导致界面处出现自旋极化态或局域磁矩，这可能有助于自旋极化表面电容。MoSe/CrSe@N-HCSs在0.1 A g下表现出498 mAh g的高容量以及良好的循环稳定性（1000次循环后容量为405 mAh g，库仑效率为99.8%）。此外，密度泛函理论（DFT）计算模拟了MoSe/CrSe@N-HCSs异质结界面处自旋极化电荷的积累，这取决于反铁磁CrSe的表面电子密度和费米能级附近的表面自旋极化。通过Mo掺杂调节电子自旋态后，材料的带隙减小。这些重要发现为设计和合成具有卓越性能特征的电池电极材料提供了新的见解。
