Kinesin-mimetic ion director enables highly oriented Zn deposition in aqueous batteries

Abstract

The practical implementation of zinc (Zn) metal electrode in rechargeable aqueous batteries remains hindered by uncontrolled dendrite formation and parasitic side reactions, primarily stemming from unregulated ion transport and high water activity. Inspired by directional cargo-transport function of kinesins, here a mimetic ion director, represented by 3-(amidinothio)-1-propanesulfonic acid (APSA), is deployed to regulate Zn deposition and suppress side reactions. When added into the electrolyte, the iso-thiourea groups of APSA selectively anchor to Zn(002) facets, mimicking microtubule-binding domain of kinesin, while the sulfonic acid groups locally concentrate Zn2+ ions near the anchored sites, resembling cargo-binding domains. This bio-inspired “anchor-capture” synergy enables dynamic, self-adaptive regulation of Zn2+ ion flux, thereby guiding oriented Zn deposition and suppressing dendrite formation. Meanwhile, APSA reduces both interfacial and bulk water activity, thus mitigating side reactions. As a result, the novel bio-inspired electrolyte dramatically extends the cycle life of aqueous Zn batteries. Remarkably, a Zn//NaV3O8·1.5H2O full battery comprising of an ultrathin Zn anode (20 µm) and a low N/P ratio (≈6) retains 93.40% of capacity after 400 cycles (over 600 h). This work provides a novel biomimetic ion transport regulation strategy that enables directional metal deposition, offering a transformative pathway toward highly stable and reversible metal batteries.