High-performance MnSe2–MnSe heterojunction hollow sphere for aluminum ion battery

Abstract

With its consistent thermal runaway temperature and superior capacity, aluminum ion batteries have emerged as a key area for battery development. At the moment, electrode material is the main focus of aluminum ion battery capacity enhancement. Selenide is anticipated to develop into a high-performance cathode for aluminum ion batteries, since it is a type of high energy density electrode material. However, because selenide is soluble in acid electrolytes, Al-Se batteries have low cycle performance and cannot keep up with the present demand for electronic gadgets. Here, homogeneous-structured precursors were created via a hydrothermal reaction, and MnSe2–MnSe heterojunction hollow spheres were created a step further via temperature control of the selenidation reaction. With 103.76 mAh/g of specific capacity remaining after 3000 cycles at 1.0 A/g, this novel heterojunction material exhibits astounding cycle stability. After additional investigation, it was shown that the MnSe2–MnSe heterojunction may prevent the dispersion of the active substances, significantly enhancing the cycle performance. The density of states (DOS) of electrode materials demonstrates the superior electronic conductivity of this heterojunction material. Meanwhile, it was computationally demonstrated that the MnSe2–MnSe heterojunction has a strong adsorption energy for AlCl4−, thus accelerating the reaction kinetics. In summary, the performance of selenides has been improved by this novel heterojunction material, which also makes for a superior cathode material.