Synergistic Anode Engineering for Aqueous Aluminium Ion Batteries: From Mechanistic Understanding to Computationally Accelerated Design

ABSTRACT

Aqueous aluminium‐ion batteries (AAIBs) combine attractive safety, low cost, and high volumetric capacity, yet their progress is limited by instability at the anode‐electrolyte interface. In aqueous media, aluminium reversibility is compromised by a cluster of intertwined processes, including hydrogen evolution, corrosion, passivation, and non‐uniform deposition. Addressing these issues through simple, scalable approaches is essential for AAIBs to move beyond laboratory research. In this review, we critically examine recent literature with a specific emphasis on studies in which one practical intervention alleviates more than one anode‐side failure mode. Through a discussion of the underlying mechanisms, this review provides a straightforward yet in‐depth understanding of anode optimisation strategies, bridging concepts across materials science, electrochemistry, and interface engineering. Practically, these approaches are organized into three categories: alloying and compositing, surface and interface engineering, and electrolyte modification. Mechanistically, these pathways converge on three main directions: (1) designing heterostructured anodes to regulate ion transport, (2) constructing protective solid electrolyte interphases in situ or ex situ, and (3) suppressing hydrolysis or reinforcing O─H bonds to block parasitic reactions. Through linking mechanistic understanding with anode materials design and electrochemical strategies, this review points to the pathways for AAIBs toward durable performance and application in sustainable energy storage.