Exposing Zn(002) texture with sucralose additive for stable and dendrite‑free aqueous zinc‑ion batteries

As the demand for safe, cost-effective and eco-friendly energy storage solutions continues to grow, aqueous zinc-ion batteries (AZIBs) have emerged as promising candidates for grid-scale applications. However, severe dendrite growth and side reactions at the zinc anode have hindered their commercial viability, particularly under high depth of discharge (DOD) and current density conditions. Now, researchers from Hefei Institute of Technology, Jiangsu University of Science and Technology, and the Chinese Academy of Sciences, led by Professor Zhaoqian Li, Professor Lei Chen and Professor Linhua Hu, have unveiled a novel electrolyte engineering strategy using sucralose (SCL) as an additive to achieve highly reversible and dendrite-free zinc anodes.

Why Sucralose Additive Matters

• Dendrite Suppression: Sucralose promotes the preferential exposure of the Zn(002) crystal facet, enabling planar and smooth zinc deposition while effectively inhibiting dendrite formation.

• Side Reaction Inhibition: By reconstructing the solvation structure around Zn²⁺ ions and reducing water activity at the anode interface, SCL suppresses hydrogen evolution reaction and corrosion.

• High Reversibility: The SCL additive enables exceptional cycling stability with high Coulombic efficiency, even under harsh conditions of high current density and deep discharge.

Innovative Mechanism and Features

• Preferential Crystal Orientation: SCL selectively adsorbs onto the Zn surface with strong binding energy (-1.39 eV), promoting Zn²⁺ nucleation and diffusion along the (002) direction for horizontal deposition.

• Solvation Structure Regulation: SCL molecules penetrate the primary solvation shell of Zn²⁺ ions, reducing the de-solvation energy barrier from 34.8 to 27.0 kJ mol^-1 while suppressing water-induced side reactions.

• Dynamic Protective Layer: The adsorbed SCL forms a stable interfacial layer that repels active water molecules, acting as a protective barrier against corrosion.

Electrochemical Performance and Applications

• Exceptional Cycling Stability: The Zn//Zn symmetric battery achieves 4900 h at 1 mA cm^-2–1 mAh cm^-2 and 171 h at 30 mA cm^-2–30 mAh cm^-2 (DOD = 73.3%).

• High Coulombic Efficiency: The Zn//Cu half battery delivers 99.61% CE at 0.2 mA cm⁻² with 0.2 mAh cm^-2 for over 4000 h.

• Full Battery Performance: The NH₄V₄O₁₀//Zn full battery retains 420 mAh g^-1 after 500 cycles at 500 mA g^-1 (90.7% capacity retention).

• Pouch Cell Validation: A practical pouch cell maintains 311 mAh g^-1 over 580 cycles at 1 A g^-1.

Future Outlook

• Practical Implementation: This work demonstrates a cost-effective approach using a commercially available sweetener to stabilize zinc anodes.

• Mechanism Extension: The strategy of regulating crystal orientation through selective adsorption provides a general framework for designing advanced electrolytes for metal anode batteries.

This study provides a practical electrolyte engineering strategy to drive the commercial development of aqueous zinc-ion batteries. Stay tuned for more groundbreaking work from Professor Zhaoqian Li, Professor Lei Chen and Professor Linhua Hu!