• • Symmetric Zn||Zn cells with PQ-7 additive sustain 2117 h of cycling at 5 mA cm−2 and 1 mAh cm−2, a 15-fold life extension versus additive-free cells (approximately 141 h). This directly addresses the industrial requirement for >2000 h operation in stationary storage, reducing battery replacement frequency and total cost of ownership.
• • Zn||Ti cells achieve Coulombic efficiency above 98% after 240 cycles, indicating that the additive suppresses HER and Zn corrosion to a level compatible with commercial viability. This metric is critical because CE below 99.9% in full cells typically leads to rapid capacity fade; the observed stability suggests that PQ-7 mitigates irreversible byproduct accumulation.
• • Zn||MnO2 full batteries retain 92.1% capacity after 1000 cycles at 1 C and 80% after 1000 cycles at 5 C. The high-rate retention (80% at 5 C) demonstrates that the additive does not impede Zn2+ transport kinetics, a common failure mode for bulky surfactant additives, and supports fast-charging applications.
• • The additive functions via competitive adsorption: PQ-7 replaces H2O and [Zn(H2O)6]2+ at the Zn surface, shielding water and homogenizing Zn2+ flux. This dual mechanism simultaneously addresses dendrite growth and HER, two degradation modes that are typically tackled separately, simplifying electrolyte formulation and reducing system complexity.