Landscaping dual-ion batteries architected by MXene materials.

Low-temperature rechargeable batteries are crucial for energy storage under subzero conditions but remain limited by sluggish ion transport, severe interfacial polarization, and slow charge-transfer kinetics. Dual-ion batteries (DIBs), employing both cations and anions as charge carriers, offer fast ion-storage kinetics and reduced desolvation barriers, yet practical applications are hindered by sluggish dual-ion diffusion, electrolyte incompatibility, and poorly understood interfacial processes. MXene materials, owing to their layered architectures, chemically tunable surfaces, and adjustable interlayer environments, all of which favor efficient ion storage and transport, are listed as electrode candidates, but suffer from nanosheet restacking, structural instability, and unresolved dual-ion storage mechanisms. This review identifies fundamental scientific questions governing low-temperature MXene-based DIBs and presents a unified mechanistic framework linking MXene chemistry, electrolyte properties, interfacial evolution, and dual-ion storage behavior. Critical challenges, materials-electrolyte-interface co-design strategies, and future research directions are highlighted to advance next-generation low-temperature DIBs.