The emerging dual-ion batteries are a sustainable analog of conventional Lithium-ion batteries. It yields high voltage output and satisfying capacity, replacing transition metal-based cathodes with graphitic carbon. Despite the advantages, the systems suffer from inadequate cycling efficiencies and triggered electrolyte decomposition on cathode surface that cut short the cycle life. As a protective measure, the carbon cathode is coated using a LiF/LixPOy/LixPOyFz-based hybrid coating layer derived from the thermal decomposition of LiPF6 salt. The coated layer acts as an artificial interface that safeguards the surface from electrolyte attack and enhances cycling efficiencies. It forms a mechanochemically robust cathode-electrolyte interface that preserves the graphitic order and structural integrity of the electrode. As a result, the bulk of the coated material is not ruptured like in the uncoated pristine sample, thereby assisting in long-term cycling. The coated material retains 85 % capacity even after 1000 cycles with a 10 % improved coulombic efficiency and 130 mV reduced voltage hysteresis instead of losing 15 % capacity within 50 cycles with poor efficiency and elevated resistances in the pristine material. The strategy brings fruitful outcomes when applied in dual carbon cell and is believed to be equally effective in other dual-ion systems.