Li Rong, Xia Liuyan, Yue Jili, Wu Junhan, Teng Xuxi, Chen Jun, Huang Guangsheng, Wang Jingfeng, Pan Fusheng
National Engineering Research Center for Magnesium Alloys, National Innovation Center for Industry-Education Integration of Energy Storage Technology, College of Materials Science and Engineering, Chongqing University, Chongqing, 400044, People's Republic of China.
Chongqing Institute of New Energy Storage Materials and Equipment, Chongqing, 401135, People's Republic of China.
Nanomicro Lett. 2025 Aug 1;18(1):17. doi: 10.1007/s40820-025-01861-7.
Micro-sized anatase TiO displays inferior capacity as cathode material for magnesium ion batteries because of the higher diffusion energy barrier of Mg in anatase TiO lattice. Herein, we report that nanosized anatase TiO exposed (001) facet doubles the capacity compared to the micro-sized sample ascribed to the interfacial Mg ion storage. First-principles calculations reveal that the diffusion energy barrier of Mg on the (001) facet is significantly lower than those in the bulk phase and on (100) facet, and the adsorption energy of Mg on the (001) facet is also considerably lower than that on (100) facet, which guarantees superior interfacial Mg storage of (001) facet. Moreover, anatase TiO exposed (001) facet displays a significantly higher capacity of 312.9 mAh g in Mg-Li dual-salt electrolyte compared to 234.3 mAh g in Li salt electrolyte. The adsorption energies of Mg on (001) facet are much lower than the adsorption energies of Li on (001) facet, implying that the Mg ion interfacial storage is more favorable. These results highlight that controlling the crystal facet of the nanocrystals effectively enhances the interfacial storage of multivalent ions. This work offers valuable guidance for the rational design of high-capacity storage systems.
由于镁在锐钛矿型TiO晶格中的扩散能垒较高，微米级锐钛矿TiO作为镁离子电池的阴极材料时容量较低。在此，我们报道了暴露（001）面的纳米级锐钛矿TiO的容量是微米级样品的两倍，这归因于界面镁离子存储。第一性原理计算表明，镁在（001）面上的扩散能垒明显低于体相和（100）面上的，并且镁在（001）面上的吸附能也明显低于在（100）面上的，这保证了（001）面具有优异的界面镁存储性能。此外，与锂盐电解质中的234.3 mAh g相比，暴露（001）面的锐钛矿TiO在镁-锂双盐电解质中的容量显著更高，为312.9 mAh g。镁在（001）面上的吸附能远低于锂在（001）面上的吸附能，这意味着镁离子的界面存储更有利。这些结果表明，控制纳米晶体的晶面可有效增强多价离子的界面存储。这项工作为高容量存储系统的合理设计提供了有价值的指导。
