Harnessing Dual Hydrogen Bonding and Lewis Acid-Base Interactions for Bio-Inspired Symmetry-Breaking Electrolytes in...

Aqueous zinc-ion batteries (ZIBs) offer a safe, cost-effective alternative for large-scale energy storage but are hindered by zinc dendrite growth, hydrogen evolution reactions (HER), and unstable electrode-electrolyte interfaces. These challenges largely stem from strong dipole interactions between symmetric water molecules and Zn²⁺, which destabilize the electric double layer (EDL) and trigger parasitic reactions. Drawing inspiration from biological systems that use asymmetric molecular interactions to regulate aqueous environments, we introduce isobutyramide (IAM) as a multifunctional electrolyte additive. IAM features both carbonyl and amide groups, enabling it to act as a dual-site hydrogen bond donor and acceptor. This disrupts the hydrogen-bonding network in water, reduces water activity, and suppresses HER. Additionally, IAM's lone pairs coordinate strongly with Zn²⁺, restructuring the solvation sheath and mitigating uncontrolled Zn²⁺ migration that leads to dendrite formation. This dual-function, symmetry-breaking strategy stabilizes the EDL, enhances Zn plating/stripping reversibility, and suppresses interfacial degradation. Electrochemical tests confirm IAM's efficacy: Zn||Cu cells exhibit 99.68% Coulombic efficiency over 1,000 cycles, Zn||Zn symmetric cells remain stable for over 4,250 h, and full-cell Zn||V₂O₅ and Zn||I₂ systems show significantly enhanced cycling performance. Zn||I₂ pouch cells also demonstrate robust long-term operation. This bio-inspired approach offers a scalable path to high-performance, practical aqueous ZIBs.