A High-Entropy Hydrogel Electrolyte Generated by Intrinsically Disordered Polymer Segments for Efficient Zinc Metal...

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Hydrogel electrolytes are promising for aqueous zinc metal batteries (ZMBs), but face challenges balancing ion conduction and electrochemical stability.
• High-entropy engineering is an emerging strategy for advanced energy storage materials, yet its application in hydrogel electrolytes is underexplored.

Purpose of the Study:

• To develop a high-entropy hydrogel electrolyte (HEHE) for ZMBs that addresses the trade-off between ion conductivity and electrochemical stability.
• To investigate the mechanisms by which high entropy influences ion transport, interfacial behavior, and zinc deposition.

Main Methods:

• Synthesized a HEHE by integrating three ionic monomers to maximize compositional diversity and entropic stabilization.
• Employed multimodal experimental characterizations and theoretical simulations to analyze the HEHE's properties.
• Assembled and tested full ZMBs utilizing the HEHE to evaluate electrochemical performance.

Main Results:

• The HEHE demonstrated entropically stabilized ion transport pathways, reduced water reactivity, and minimized ion pairing.
• Achieved selective cation conduction, uniform ionic flux, low-energy interfacial desolvation, and crystallographic zinc deposition.
• Enabled stable ZMB operation at a high areal capacity of 3.2 mAh cm^-2, outperforming low-entropy counterparts.

Conclusions:

• Entropy-driven design is a viable and generalizable strategy for developing advanced soft ion conductors.
• The HEHE approach successfully circumvents the conductivity-stability dilemma in hydrogel electrolytes for ZMBs.
• This work expands the application of high-entropy materials to aqueous batteries and other soft ionic conductor systems.