Ding Shiqi, Dai Xin, Tian Yuxin, Song Guanying, Li Zhenjiang, Meng Alan, Wang Lei, Li Guicun, Wang Wenjun, Huang Jianfeng, Li Shaoxiang
College of Materials Science and Engineering, College of Electromechanical Engineering, Qingdao University of Science and Technology, Qingdao 266042, Shandong, P. R. China.
School of Material Science and Engineering, International S&T Cooperation Foundation of Shaanxi Province, Xi'an Key Laboratory of Green Manufacture of Ceramic Materials, Shaanxi University of Science and Technology, Xi'an 710021, Shanxi, P. R. China.
ACS Appl Mater Interfaces. 2021 Nov 17;13(45):54005-54017. doi: 10.1021/acsami.1c17023. Epub 2021 Nov 5.
The development of cathode materials with a high electric conductivity and a low polarization effect is crucial for enhancing the electrochemical properties of magnesium-ion batteries (MIBs). Herein, Mo doping and nitrogen-doped tubular graphene (N-TG) introduction are carried out for decorating VS (Mo-VS/N-TG) via the one-step hydrothermal method as a freestanding cathode for MIBs. The results of characterizations and density functional theory (DFT) reveal that rich sulfur vacancies are induced by Mo doping, and N-TG as a high conductive skeleton material serves to disperse the active material and forms a tight connection, all of which collectively improved the electrical conductivity of electrode and increased the adsorption energy of Mg (-6.341 eV). Furthermore, the fast reaction kinetics is also confirmed by the galvanostatic intermittent titration technique (GITT) and the pesudocapacitance-like contribution analysis. Benefiting from the synergistic effect of electrical conductivity enhancement and rich vacancy introduction, Mo-VS/N-TG delivers a steady Mg storage specific capacity of about 140 mAh g at 50 mA g, outstanding cycle stability (80.6% capacity retention ratio after 1200 cycles under 500 mA g), and excellent rate capability (specific capacity reaches 77.1 mAh g when the current density reaches 500 mA g). In addition, the reversible reaction process, intercalation mechanism, and structural stability during the Mg insertion/extraction process are confirmed by a series of characterizations. This research provides a sustainable and scalable strategy to spur the development of MIBs.
