A phosphorous-doped graphite felt (PGF) is fabricated and examined as electrode for vanadium flow battery (VFB). P doping improves the electrolyte wettability of GF and induces more defect sites on its surface, resulting in significantly enhanced activity and reversibility towards VO2+/VO2 + and V2+/V3+ couples. VFB with PGF electrode demonstrates outstanding performance such as high-rate capability under 50–400 mA cm−2, wide-temperature tolerance at −20 °C–60 °C, and excellent durability over 1000 charge–discharge cycles. These merits enable PGF a promising electrode for the next-generation VFB, which can operate at high-power and all-climate conditions.