Zinc Iodide (ZnI2, >99.99%) Powder as Cathode and Electrolyte Additive for Aqueous Zinc Ion Battery, 25-100 g/bottle, CAZIBCEAZnI2

In aqueous zinc-based energy storage, Zinc Iodide (ZnI2) plays a dual and transformative role. It is utilized either as the primary active material in aqueous zinc-iodine (Zn-I2) batteries (or flow batteries) or as a functional electrolyte additive in standard aqueous zinc-ion batteries (AZIBs).

Cathode/Catholyte Material (Zn-I2 Chemistry): When ZnI2 serves as the core chemical component, the system relies on a fast, reversible two-electron conversion redox reaction between iodide ions (I-) and iodine (I2). (i) High Theoretical Capacity: The iodine/iodide redox couple delivers a high specific capacity (around 211 mAh/g based on iodine), operating at a stable potential plateau of ~1.2–1.3 V versus Zn/Zn^{2+}. (ii) Fast Kinetics: Unlike insertion-type solid-state cathodes (such as manganese oxides or Prussian blue analogs) which suffer from sluggish solid-state diffusion, the liquid-phase redox kinetics of I-/I3^- enable high-rate capabilities and excellent power density.

Electrolyte Additive in Standard Zinc-Ion Batteries: When added in smaller, targeted quantities to the electrolyte of conventional aqueous zinc-ion cells, ZnI2 acts as an interfacial modifier to protect the zinc metal anode: (i) In-Situ Protective SEI Formation: Iodide ions (I-) have a strong affinity for the zinc metal surface. Upon initial charging, they preferentially adsorb onto active sites and react with zinc to form an in-situ zinc iodide (ZnI2) or zinc-rich hybrid passivating layer (often working in tandem with ZnF2 or organic components if other salts/additives are present). (ii) Suppressing Dendrites and Side Reactions: This artificial solid-electrolyte interphase (SEI) homogenizes the local electric field and Zn^{2+} flux across the interface. By shielding the zinc metal from direct contact with free water molecules in the aqueous medium, it drastically curtails parasitic hydrogen evolution reaction (HER) and suppresses zinc dendrite growth during prolonged stripping/plating cycles.

Notes: (1) Please store the ZnI2 powder in a dry area (glovebox or dryroom is preferred)

References: 

1. J. Zhu, et al. Stabilizing Iodine Redox Mediator Enables High-Performance Aqueous Zinc–Sulfur Batteries, Adv. Mater., 2026, 38, e72455
2. B. Ye, et al. Electrolyte Regulation toward Cathodes with Enhanced-Performance in Aqueous Zinc Ion Batteries, Adv. Mater., 2025, 37, 2501538