Biomimetic shunt effects to simultaneously regulate solvation and interface structure for high-performance Zn metal...

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Aqueous zinc ion batteries face challenges like hydrogen evolution reaction (HER) and zinc dendrite growth.
• Optimizing electrolytes and electrodes is crucial, but simultaneously regulating solvation structure and the electrode/electrolyte interface remains underexplored.

Purpose of the Study:

• To develop a novel approach using a biomass-derived additive to simultaneously regulate the solvation structure and electrode/electrolyte interface in aqueous zinc ion batteries.
• To enhance the safety and cycle life of zinc anodes by suppressing HER and dendrite formation.

Main Methods:

• Xylan (XL), inspired by hemicellulose, was designed as a trace electrolyte additive (ZS@XL).
• The ZS@XL additive was dispersed in the aqueous electrolyte and adsorbed onto the zinc anode.
• The effects of XL on ion flux, water-electrolyte interaction, and zinc ion solvation were investigated.

Main Results:

• The xylan-adsorbed layer on the zinc anode acted as "shunt channels" for uniform ion flux and a physical barrier against water, suppressing dendrite growth and HER.
• Xylan's high binding energy with Zn²⁺ disrupted the Zn(H₂O)₆²⁺ solvation structure, reducing active water and promoting faster desolvation.
• The modified zinc anode achieved 1400 cycles of plating/stripping reversibility and a 2800-hour cycling life.
• A Zn-iodine (I₂) full battery with ZS@XL demonstrated 16,000 cycles and practical application in powering electric instruments.

Conclusions:

• This work introduces a novel strategy using biomass materials to simultaneously regulate the electrolyte solvation structure and electrode/electrolyte interface for high-performance aqueous zinc ion batteries.
• The ZS@XL additive offers a promising solution for enhancing the safety and longevity of zinc anodes, paving the way for practical applications.