AbstractCobalt hydroxide (Co(OH)2) is a promising electrode material for hybrid devices because of its intrinsic battery‐mimic mechanism for energy storage. However, conventional electrolytes suitable for Co(OH)2 will lead to performance failure in a harsh environment, which hinders its industrial application at ambient temperature. Here, we propose an anti‐freezing aqueous electrolyte composed of NaOH and a high concentration of NaClO4 for Co(OH)2 electrode, which can still fully function at −30 °C. At this temperature, the energy density of a Co(OH)2–active carbon hybrid capacitor can reach 16.52 Wh kg−1, which has a 72 % energy‐density retention at 20 °C. The hybrid capacitor shows excellent cyclability with the anti‐freezing electrolyte at −30 °C, presenting only 3.5 % drop of the capacitance after 500 cycles. This designed anti‐freezing electrolyte may put more pseudocapacitive materials into more practical use, particularly in northern harsh climates.