AbstractHigh voltage spinel LiNi_0.5 Mn_1.5O₄ (LNMO) is a promising material for next generation lithium‐Ion batteries. However, its reactivity near 5 V possess stability and cycling challenges. In this study, a novel integrated approach is employed using a single lithium‐ion conducting polymer binder (SLICPB) to prevent interactions with reactive anions and create a protective layer against electrolyte decomposition. The proposed SLICPB in‐situ polymerization in the LNMO electrodes simplifies the preparation process, reducing costs. SLICPB properties effectively decrease polarization by concentration. For instance, at a discharge capacity of 68 mAh g⁻¹, the voltage hysteresis difference is 0.31 V, enabling higher capacity at 1 C (a 38 % increase) compared to traditional binder electrodes. Notably, this integrated strategy completely replaces the traditional binder without any need for additives, thus avoiding any extra weight in the electrode preparation. Furthermore, SLICPB properties successfully decreasereactivity and diminish the leaching of Mn²⁺, as evaluated through differential electrochemical mass spectrometry and electron paramagnetic resonance, respectively.