Facile preparation of three-dimensional cubic MnSe ₂ and application in aqueous copper-ion batteries

To address the urgent demand for advanced electrode materials in high-performance aqueous copper-ion batteries (ACIBs), manganese selenide (MnSe 2 ) was successfully synthesized as a cathode material via a facile hydrothermal method. Systematic investigations were conducted to evaluate the effects of hydrothermal reaction temperature and duration on the surface morphology and microstructure of MnSe2, while a comprehensive analysis of the Cu 2+ storage mechanism was also performed. The results demonstrated that MnSe 2 exhibited outstanding electrochemical performance under the optimal hydrothermal conditions of 180°C and 12 h of reaction time. During the Cu 2+ storage process of MnSe 2 , the reversible intercalation behavior of Cu 2+ underwent adaptive adjustment with the transformation of the lattice structure. This unique feature enabled the electrode to maintain a high discharge specific capacity of 572 mAh g -1 after 500 cycles at a current density of 2 A g -1 . Overall, this work provided a practical and highly promising strategy for the design and development of high-performance materials for ACIBs, offering significant implications for advancing the application of ACIBs in next-generation energy storage systems.