Bioinspired by the “adhesion–conduction” blueprint of spider webs, a team from Lanzhou University, Nankai University, and Lanzhou Jiaotong University has unveiled a hierarchical hydrogel electrolyte that aims to eliminate one of aqueous zinc-ion batteries’ toughest trade-offs: pairing flexibility and safety with rapid zinc-ion transport and dendrite suppression. In flexible devices, conventional hydrogel strategies often immobilize reactive water or over-constrain solvation dynamics—reducing side reactions but also slowing Zn²⁺ movement in a way that accelerates polarization and failure.
The breakthrough centers on a new electrolyte architecture (MTP) that is designed to behave like a scaffolded transport network rather than a passive water reservoir. Researchers explain that the binding hydrogen-bond networks typically used to stabilize hydrogels can unintentionally trap solvated Zn²⁺, worsening concentration gradients at higher current densities and undermining Coulombic efficiency.
To overcome this paradox, MTP is built through a straightforward one-pot thermal polymerization that integrates tannic-acid–modified MXene nanosheets (MT) into a polyacrylamide (PAM) matrix. Rather than relying on a single mechanism, the design combines mechanical resilience with directed ion migration: PAM provides structural “web threads,” while the MXene/tannic acid components generate dense polar “sticky sites” that interact selectively with water and ions at the electrode interface.
Computational studies—Monte Carlo simulations and density functional theory—support the claimed synergy. The sticky sites are proposed to coordinate with water molecules to suppress interfacial side reactions and hydrogen evolution, while also lowering barriers to Zn²⁺ desolvation. This dual effect helps homogenize the ion flux and reduces the energetic penalties that typically promote nonuniform deposition.
Electrochemically, the MTP electrolyte reaches an ionic conductivity of 27.69 mS cm⁻¹ and a Zn²⁺ transference number of 0.833, values that outperform many traditional aqueous and less structured hydrogel electrolytes. In symmetric Zn//Zn cells, the system sustains an ultralong lifetime of 4600 hours (>6 months) at 0.5 mA cm⁻², and remains stable even when the current density is doubled.
Crucially, the optimized interface chemistry tunes the nucleation overpotential to 68 mV, promoting uniform Zn deposition with a textured (002) growth preference and effectively suppressing dendrite formation. In half-cells, Zn//Cu cycles last beyond 850 rounds with an average Coulombic efficiency of 98.57%, while Zn//Z-VO full cells retain 74.5% capacity after 2000 cycles at 2 A g⁻¹ and demonstrate a remarkable 10,000-cycle durability at 5 A g⁻¹.
When translated to flexible pouch cells, the electrolyte supports a high specific capacity of 234.22 mAh g⁻¹ and maintains 76.16% retention after 1000 cycles at 1 A g⁻¹, showing negligible performance fluctuation across bending angles from 0° to 180°. Together, these results position MTP as a viral, biomimetic pathway for next-generation flexible energy storage that does not force safety, conductivity, and cycling life to compete.
Subject of Research:
Hydrogel electrolyte design for flexible zinc-ion batteries
Article Title:
Bioinspired Hierarchical Hydrogel Electrolyte for Ultralong‑Life Flexible Zinc‑Ion Batteries
News Publication Date:
10-Jun-2026
Web References:
http://dx.doi.org/10.1007/s40820-026-02246-0
References:
Nano-Micro Letters. DOI: 10.1007/s40820-026-02246-0
Image Credits:
Ran Wang, Qian Gao, Runhai Wu, Yongqi Mi, Shaopei Yang, Hongxiao Wang, Ting Wan, Sehrish Gull, Kefeng Xie, Guankui Long, Pengcheng Du*
Keywords
Hydrogels
