Oxygen-redox-based Li-rich layered oxide cathode materials always suffer from severe voltage decay, because of progressively structural transformation. An initial consensus is that less utilization of oxygen redox in these cathodes would retard this process on cycling. In this work, we find sufficient oxygen redox in Li 1.26 Ni 0.0741 Co 0.0741 Mn 0.593 O 2 that contributes toward the available capacity of 80.5% can deliver a specific capacity of 280 mAh g −1 with the retentions of voltage and capacity of ∼96.7% and 97.1% after 50 cycles, respectively. The suppressed voltage decay with sufficient oxygen redox is originated from the stabilizing effect of vast disordered structures generated by the initial electrochemical activation. Based on a unique disorder−order transition induced by temperature, the degree of the concentration of the disordered structures is well-revealed through temperature-dependent in situ X-ray diffraction and Raman spectroscopy. The abundant disordered structures via sufficient oxygen redox activation are believed to act as an accommodator to promote structural stability.R echargeable lithium-ion batteries have dominated the market of electric energy storage devices for decades. Cathodes with high energy density have always been the pursuit of the goal to meet the ever-increasing demands. 1−4 At present, Li-rich layered oxides (LLOs) stand out among the others, because of its ultrahigh capacity. Exploiting oxygen redox has demonstrated a subsistent way to contribute to the considerable capacity. 5,6 Unfortunately, the activation of the oxygen redox also brings detrimental structural changes, resulting in structure degradation and, thus, the notorious voltage decay upon cycling. 7 So far, the state-of-the-art characterization techniques have provided multiscale structure and spectroscopy information to understand the structure evolution of LLOs. 8−12 It is now believed that a series of disordered structures generated, such as lattice distortion, dislocation, and stacking faults, disturb the structure stability. 10,11,13 Some unusual ways are proposed to suppress structures degradation effectively. Embedding the undesired disordered structures into pristine host structures is favored to promote the structure stability. 14−17 Our recent work further illustrates that subtle adjustments of the disordered structures from type/range/distribution are necessary to mobilize them as a modification method. 14 The role of