Wei Luyao, Lian Ruqian, Zhao Yingying, Meng Yuan, He Li, Yu Yue, Chen Gang, Wei Yingjin
Key Laboratory of Physics and Technology for Advanced Batteries (Ministry of Education), Jilin Engineering Laboratory of New Energy Materials and Technology, College of Physics , Jilin University , Changchun 130012 , P.R. China.
College of Physics and Optoelectronic Engineering , Harbin Engineering University , Harbin 150001 , China.
ACS Appl Mater Interfaces. 2020 Feb 26;12(8):9316-9321. doi: 10.1021/acsami.9b21540. Epub 2020 Feb 17.
Magnesium ion batteries (MIBs) have attracted increasing attention due to their advantages of abundant reserves, low price, and high volumetric capacity. However, the large Coulombic interactions of Mg with the cathode framework seriously hinder the rate capability and cycle stability of the battery cell. For this reason, finding a suitable cathode material has become a main task in MIB research. In this study, NiSe was first proposed as a new cathode material for MIBs. First-principles calculations showed that NiSe could accommodate up to 1 mol of Mg, but the migration energy barrier was as high as 1.35 eV. Accordingly, nanosized NiSe was prepared by a hydrothermal method to achieve satisfying electrochemical performance. The prepared NiSe material showed a discharge capacity of 99.8 mA·h·g at 50 mA·g current density with a capacity retention of 75% after 100 cycles. Combined with first-principles calculations and spectroscopic studies, it was demonstrated that the material underwent a solid-solution structural change during Mg insertion, with all charge transfer taking place on the Ni cations.
镁离子电池（MIBs）因其储量丰富、价格低廉和体积容量高的优点而受到越来越多的关注。然而，镁与阴极骨架之间的大库仑相互作用严重阻碍了电池的倍率性能和循环稳定性。因此，寻找合适的阴极材料已成为MIB研究中的一项主要任务。在本研究中，首次提出将NiSe作为MIBs的新型阴极材料。第一性原理计算表明，NiSe最多可容纳1 mol的镁，但迁移能垒高达1.35 eV。因此，采用水热法制备了纳米级NiSe，以实现令人满意的电化学性能。制备的NiSe材料在50 mA·g电流密度下放电容量为99.8 mA·h·g，100次循环后容量保持率为75%。结合第一性原理计算和光谱研究表明，该材料在镁嵌入过程中发生了固溶体结构变化，所有电荷转移均发生在镍阳离子上。
