Tailoring the morphologies of molybdenum selenides with improving their electrochemical performances for supercapacitors

• Published in: Journal of energy storage 2024-06, Vol.89, p.111671, Article 111671
• Main Authors: Zhu, Xinyuan, Feng, Ziyu, Fan, Lele, Wang, Qifeng, Wei, Yue, Zhu, Lei, Li, Na, Zhang, Qinfang
• Format: Article
• Language: English
• Subjects: Electrochemical performance; Electrodeposition; Molybdenum selenide; Morphology control; Supercapacitor
• ISSN: 2352-152X; 2352-1538
• DOI: 10.1016/j.est.2024.111671

As an outstanding energy storage device, supercapacitor has garnered extensive concerns due to its unique features. Designing and constructing architected structures can particularly improve their electrochemical performances. In this study, we explore a facile strategy to synthesize porous molybdenum selenide (MoSex) nanosheets for supercapacitors. It's interestingly found that the morphologies can be noticeably modulated by controlling the molar ratio of Mo/Se. Electrochemical performances indicate the as-prepared MoSex nanosheets exhibit an impressive capacitance of 2499.1 F/g at 5 A/g. More importantly, the high-performance cathodes with fascinating structures could allow a broad Mo/Se molar ratio, exhibiting a flexible synthesis merit. Although the capacitance rapidly decays with increasing cycles, a considerable capacitance of 1278.4 F/g at 1 A/g is maintained after 1000 cycles. A detailed kinetic analysis is conducted to further understand their electrochemical storage behavior. Furthermore, we assemble an asymmetric supercapacitor and the device delivers a capacitance of 49.7 F/g, and a maximal energy density of 25.3 Wh/kg at a power density of 1143.6 W/kg. Additionally, we explore the annealing effect on capacitance and stability, and the newly assembled supercapacitor displays a superior rate performance, without prominent degradation in energy density as improving power density, as well as enhancing durability. [Display omitted] •A facile strategy was provided to prepare porous molybdenum selenides (MoSex) cathodes.•The morphologies were modulated by controlling the molar ratio of Mo/Se.•The as-prepared porous MoSex nanosheets possessed a capacitance of 2499.1 F/g at 5 A/g.•The assembled supercapacitor owned a capacitance of 49.7 F/g, with high energy density.