ABSTRACT Rechargeable Zn–organic batteries hold great promise for sustainable energy storage, yet most reported high performances are achieved only at low mass loadings (2–3 mg cm −2 ), far from practical application. Here, we investigate poly(benzoquinonyl sulfide) (PBQS) electrodes working in a water‐in‐salt electrolyte and reveal that PBQS first undergoes faradaic proton insertion during discharge, which is subsequently displaced by Zn 2+ , releasing protons back into the electrolyte. This dynamic relay allows a small amount of H + to cycle repeatedly, acting as a kinetic buffer that offset the sluggish diffusion of Zn 2+ . Owing to this mechanism and PBQS's high conductivity, a low‐carbon (10 wt.%) PBQS electrode with an ultrahigh mass loading of 100 mg cm −2 delivers a capacity of 187.1 mAh g −1 (∼96% of low‐loading capacity) and achieves a record areal capacity of 18 mAh cm −2 . The electrode also exhibits excellent rate capability and cycling stability, suggesting its strong potential for practical applications.
Yu et al. (Thu,) studied this question.