Yang, Y; Huang, X; Xiang, Y; Chen, Shu; Guo, Lei; Leng, S; Shi, Wei
A simple, green, efficient, and controllable electrochemical potential perturbation method has been developed to synthesize Mn3O4 nanomaterials. No toxic or explosive chemicals are used during the fabrication process. Taking pure Mn metal as the working electrode and 2 M KCl aqueous solution as the electrolyte solution, the Mn3O4 products with rod-like, spherical-like and mixed structures can be obtained through cyclic voltammetry technology under rapid scan rates of 5, 200 and 50 V s(-1) within a potential range of -2.0 to 2.0 V (vs Saturated calomel electrode, SCE), respectively. Rapid and repeated redox treatment of Mn metal surface accompanying intense oxygen and hydrogen evolution will lead to the dispersion of Mn metal and the formation of the Mn3O4 nanomaterials. The lithium-ion storage behaviors of these as-fabricated Mn3O4 nanomaterials have been studied contrastively, showing that the spherical-like Mn3O4-S nanoparticles with the highest Li-ion chemical diffusion coefficient display the best cycling stability and rate capability. As a consequence, it shows an excellent specific capacity of up to 780 mAh g(-1) after 250 cycles a high rate of 1000 mA g(-1) and a good rate capability of 895, 798, 722, 683, 601 and 530 mAh g(-1) at current densities of 200, 500, 800, 1000, 1500 and 2000 mA g(-1), respectively. This work is of importance for energy storage as it provides a new and efficient electrochemical way for the fabrication of anode materials for the next-generation LIBs with outstanding electrochemical performances. (C) 2018 Elsevier B.V. All rights reserved.
