Aqueous Multivalent Ion (Mg2+, Al3+, Ca2+) Batteries

Aqueous multivalent ion batteries (AMVIBs) have garnered significant attention from both the academic and industrial sectors due to their unique advantages: low cost, environmental friendliness, and high safety. Compared to the organic electrolytes used in traditional lithium-ion batteries, aqueous electrolytes reduce the emission of harmful chemicals during battery production and disposal, resulting in a smaller environmental impact. Additionally, the polyvalent metals used are less expensive than materials like lithium, offering higher charge storage capacity and energy density while significantly reducing the risk of fire and chemical leakage. However, despite the above advantages of aqueous multivalent ion batteries, they still face a series of challenges in multiple areas, such as the narrow electrochemical window of water and the complex electrochemical behavior of multivalent ions in aqueous solutions, which leads to rapid degradation of electrode materials. To further enhance the performance of AMVIBs, researchers have proposed various methods, which have been extensively studied and used individually or in combination. This chapter aims to provide a comprehensive introduction to AMVIBs, including anode, cathode, and electrolyte regulation.