Hydrogen‐Bond‐Assisted Solution Discharge in Aprotic Li–O₂ Batteries

Abstract Surface discharge mechanism induced cathode passivation is a critical challenge that blocks the full liberation of the ultrahigh theoretical energy density in aprotic Li–O₂ batteries. Herein, a facile and universal concept of hydrogen‐bond‐assisted solvation is proposed to trigger the solution discharge process for averting the shortcomings associated with surface discharge. 2,5‐Di‐tert‐butylhydroquinone (DBHQ), an antioxidant with hydroxyl groups, is introduced as an exemplary soluble catalyst to promote solution discharge by hydrogen‐bond‐assisted solvation of O₂⁻ and Li₂O₂ (OH···O). Thus, a Li–O₂ battery with 50 × 10⁻³ m DBHQ delivers an extraordinary discharge capacity of 18 945 mAh g⁻¹ (i.e., 9.47 mAh cm⁻²), even surpassing the capacity endowed by the state‐of‐the‐art reduction mediator of 2,5‐di‐tert‐butyl‐1,4‐benzoquinone. Besides, an ultrahigh Li₂O₂ yield of 97.1% is also achieved due to the depressed reactivity of the reduced oxygen‐containing species (O₂⁻, LiO₂, and Li₂O₂) by the solvating and antioxidative abilities of DBHQ. Consequently, the Li–O₂ battery with DBHQ exhibits excellent cycling lifetime and rate capability. Furthermore, the generalizability of this approach of hydrogen‐bond‐assisted solution discharge is verified by other soluble catalysts that contain OH or NH groups, with implications that could bring Li–O₂ batteries one step closer to being a viable technology.