Aqueous batteries, especially for aqueous proton batteries (APBs) have received wide attention, due to safe and profitable advantages. In this work, CNT-C4N composites have been prepared by in-situ synthesizing C4N polymer on the surface of CNT, and used as the anode electrode for APBs. The introduction of CNT not only increase the utilize ratio of active sites, but also effectively alleviate the dissolution of C4N in the electrolyte. The assembled MnO2@CF//C4N-40% CNT battery depicts a discharge capacity above 180 mAh g-1 (1 A g-1) in acid electrolyte. Moreover, surprisingly, the full battery still delivers excellent electrochemical properties at the frozen electrolyte owing to excellent anti-freezing properties of acidic electrolytes and distinctive diffusion-free Grotthuss mechanism. Unexpectedly, even the temperature decreased to −70  \(^\circ{\rm C} \) , the resultant full battery still displays a specific capacity of 120.1 mAh g-1 under low current density (0.1 A g-1.) This work could provide a new design strategy for developing high-performance aqueous solid-state proton batteries.