Electrolytes for Aluminum-Ion Batteries: Progress and Outlook

Aluminum-ion batteries (AIBs) are promising electrochemical energy storage sources because of their high theoretical specific capacity, light weight, zero pollution, safety, inexpensiveness, and abundant resources. These theoretical advantages have recently made AIBs a research hotspot. However, electrolyte-related issues significantly limit their commercialization. The electrolyte choices for AIBs are significantly limited, and most of the available options do not facilitate the Al3+/Al three-electron transfer reaction. Thus, this review presents an overview of recent advances in electrolytes and modification strategies for AIBs to clarify the limitations of existing AIB electrolytes and offer guidance for improving their performance. Furthermore, herein, the advantages, limitations and possible solutions for each electrolyte are discussed, after which the future of AIB electrolytes is envisioned. This review presents an overview of recent advances in electrolytes in aluminum-ion batteries (AIBs). AIB electrolytes mainly include liquid and solid electrolytes. The main research directions in liquid electrolytes for AIBs mainly include electrolyte solutes, "water-in-salt" (WIS) electrolytes, and electrolyte additives image