Dual-ion batteries (DIBs) are one of the promising candidates to meet the low-cost requirements of commercial applications because of their high working voltage, excellent safety, and environmental friendliness. In addition to the electrolyte, the research on DIBs mainly focuses on the electrode materials, especially the high-performance anodes. Alloy-type materials, such as Si, Sn, Al, and so forth, are promising alternative anodes owing to their large abundance, excellent conductivity, and especially high specific capacity. However, the alloy-type anodes tend to pulverize due to the excessive volume expansion during the alloying/dealloying process, along with repeated growth/fracture of the solid electrolyte interphase (SEI) layer and continuous consumption of the electrolyte. Herein, we have successfully developed an amorphous carbon nanointerface (ACNI) (<10 nm) coated on an Al anode that acts as an artificial SEI to prevent the continuous growth of the formed SEI layer and maintain its structural stability. Further, pairing this ultrathin ACNI/Al anode with the graphite cathode constructs proof-of-concept DIBs, exhibiting significantly improved performances with a specific capacity of 115 mA h g −1 and a capacity retention ratio of ∼94% after 1000 cycles.