Boosting potassium storage in nanosheet assembled MoSe2 hollow sphere through surface decoration of MoO2 nanoparticles

• Published in: Applied surface science 2020-03, Vol.505, p.144573, Article 144573
• Main Authors: Jiang, Qingqing, Hu, Sha, Wang, Lin, Huang, Zhengxi, Yang, Hai-Jian, Han, Xiaole, Li, Yongxiu, Lv, Chao, He, Yu-Shi, Zhou, Tengfei, Hu, Juncheng
• Format: Article
• Language: English
• Subjects: Anode materials; MoO2; MoSe2; Nano-heterostructure; PIBs
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2019.144573

Herein, the MoSe2@MoO2 heterojunction was used as a novel anode material for PIBs and the electrochemical performance was greatly improved. By introducing metallic MoO2 can improve the electrical conductivity and the well dispersed MoO2 nanoparticles prevent the restacking of MoSe2 nanosheets, furthermore, the MoSe2@MoO2 heterostructures facilitate interfacial electron transport and built-in electric field makes the diffusion of K-ion easier. [Display omitted] •The MoSe2@MoO2 heterojunction was used as a novel anode material for PIBs.•The heterojunction electrode shows high electrochemical performance.•The embedded metallic MoO2 not only improve the electrical conductivity, but also maintain the structure stability.•The built-in electric field of MoSe2@MoO2 heterostructures makes the diffusion of K-ion easier. Considering the suitable redox potential, low price, and abundant resource of potassium, potassium-ion batteries (PIBs) have attracted considerable attention as one of the alternatives to lithium-ion batteries (LIBs), however, the larger ionic radius of potassium ions makes it difficult to select suitable electrode materials. Herein, the MoSe2@MoO2 heterojunction in which MoO2 nanoparticles embedded on MoSe2 nanosheets was synthesized by hydrothermal method and used as a novel anode material for PIBs. The electrochemical performance of the heterojunction was greatly improved as compared with the pure MoSe2 and pure MoO2. At the current density of 500 mA g−1 after 100 cycle, the heterojunction electrode still maintains a capacity of 255 mA h g−1 and the coulomb efficiency is close to 100%. By introducing metallic MoO2 can improve the electrical conductivity, furthermore, the MoSe2@MoO2 heterostructures facilitate interfacial electron transport and built-in electric field makes the diffusion of K-ion easier. In addition, the well dispersed MoO2 nanoparticles prevent the restacking of MoSe2 nanosheets and maintain the structure stability during the charge/discharge process.