MoO₃ nanobelts cathode promotes Al³⁺ insertion in aqueous aluminum-ion batteries

Aqueous aluminium ion batteries (AAIBs) have attracted much attention due to their high theoretical capacity, safety, and environmental friendliness. However, the Research and Development (R&D) of cathode materials has limited its development and application. MoO₃ has been proven to be a reliable and stable cathode material, nevertheless, it faces the dilemma of poor cycling performance and low specific capacity in AAIBs due to the irreversible phase transition in its structure. In this paper, MoO₃ synthesized by a hydrothermal method has a unique nanobelt structure, which significantly enhances the structural stability of MoO₃ and reduces its structural damage during charging/discharging. In addition, the nanobelt structure also gives MoO₃ a rougher surface, which provides a large number of active sites and spaces for the insertion and extraction of Al³⁺ and improves the diffusion rate of Al³⁺ to a large extent. Experimental results demonstrate that this MoO₃ nanobelt cathode exhibits significantly improved cycling stability and high specific capacity in AAIBs. This paper provides a practical solution to the existing challenges of AAIBs and further promotes the development and application of molybdenum-based materials in AAIBs.