The conventional polymer binder, polyvinylidene fluoride ( PVDF), severely restricts further improvements in battery performance due to inherent drawbacks, including low electronic/ionic conductivity, insufficient adhesion, and a tendency to swell in electrolytes, which can trigger thermal runaway. In this study, an organoruthenium catalyst ( C₃₁H₃₇C₂N₃O₃Ru) was selected to prepare highly saturated hydrogenated nitrile butadiene rubber (HNBR) with a hydrogenation degree over 99% via emulsion hydrogenation. By systematically investigating various reaction parameters, the optimal hydrogenation conditions were determined as follows, a catalyst dosage of 0.015% (relative to the dry rubber content), a hydrogen pressure of 8 MPa, a solid content of 30% , a reactor fill ratio of 60% , and a reaction time of 5 h. The synthesized HNBR was applied as cathode binder in lithium-ion half-cells to evaluate its long-term cycling stability and rate capability. Results demonstrate that, compared to commercial PVDF, the HNBR-based cathode exhibits an initial specific capacity of 135 mAh/g and maintains a high capacity of 140 mAh/g after 500 cycles, showing no capacity fading. Furthermore, it displays excellent rate performance, with the discharge capacity recovering to 145 mAh/g upon restoring the initial current density. The development of HNBR as cathode binder in this study provides a novel strategy to overcome key bottlenecks in battery performance enhancement, offering significant potential for the sustainable advancement of battery industry.