Recently, Professors Li Shandong and Associate Professor Wang Xia of Qingdao University published a 3D Ordered Porous Hybrid of ZnSe/N-doped Carbon with Anomalously High Na+Mobility and Ultrathin Solid Electrolyte in the international top journal Advanced Functional Materials Interphase for Sodium-Ion Batteries" research paper. The first authors of the paper are Li Xueying and Han Zhiyuan, master students of the School of Physical Sciences, and Professor Yang Wenhua, and the corresponding authors are Associate Professor Wang Xia, Professor Li Shandong, and Professor Wu Xinglong of Northeast Normal University.
Transition metal selenide has a high theoretical specific capacity, appropriate working voltage, abundant reserves and good thermal stability, and is a class of alkali metal ion battery anode materials with great research value. However, transition metal selenides have problems such as slow reaction kinetics and poor structural stability during the cycle. At the same time, the inherent properties of transition metal selenides and the differences in ion radius and electronegativity between alkali metal ions lead to differences in the storage behavior of Li+/Na+/K+, and the specific reasons for this difference are not clear.
Professors Li Shandong and Associate Professor Wang Xia, with ZnSe as the research object, studied for the first time the difference between ZnSe's storage behavior on Li+/Na+/K+ through a combination of first-principles computation and experiments. The results showed that ZnSe had better Na+ kinetics compared to Li+ and K+. In order to further improve the Na+ diffusion coefficient, cycle stability and magnification properties of ZnSe in the cycle process, the authors adopted the dual strategy of regulating the microstructure of the material and optimizing the electrolyte, on the one hand, the hybrid material of 3D ordered hierarchical pore ZnSe and nitrogen-doped carbon (3DOHP ZnSe@N, C) was designed and synthesized; on the other hand, the electrolyte was optimized to form a thinner and stable SEI. Based on this, sodium-ion batteries composed of 3DOHP ZnSe@N, C as the anode material, and NaOTf as the electrolyte show excellent magnification properties and good cycle stability. At the same time, the sodium storage mechanism of 3DOHP ZnSe@N and C, as well as the structure and composition of SEI, were further studied by means of in situ XRD, non-situ TEM and XPS. This study provides a new idea for the design of electrode materials for high-performance sodium-ion batteries.
Professor Li Shandong and Associate Professor Wang Xia have long been engaged in the research of new ion batteries, and have made a series of important progress, with Qingdao University as the first unit to publish a number of relevant academic papers in a number of high-level journals, including Nano-Micro Lett., ACS Appl. Mater. Interfaces, etc.
Source: Qingdao University
Thesis Link:
https://doi.org/10.1002/adfm.202106194