Advanced cathodes for aqueous Zn batteries beyond Zn²⁺ intercalation

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Aqueous zinc batteries are crucial for energy storage, but cathode development lags behind anode advancements.
• Existing Zn²⁺/H⁺ intercalation cathodes face challenges like high diffusion barriers, pH instability, and poor reproducibility.

Purpose of the Study:

• To critically assess non-intercalation cathode materials for aqueous zinc batteries.
• To identify strengths, weaknesses, and performance-boosting strategies for these alternative cathodes.
• To evaluate the transition potential from lab-scale research to industrial applications.

Main Methods:

• Review of existing literature on non-intercalation cathode mechanisms (conversion, hybrid, anion insertion, deposition/dissolution).
• Analysis of performance data and limitations of various cathode materials in small-scale aqueous zinc batteries.
• Assessment of research gaps and industrial scalability challenges.

Main Results:

• Non-intercalation mechanisms offer broader cathode design possibilities beyond traditional intercalation.
• Sulfur (S), iodine (I₂), and bromine (Br₂) based electrodes show significant commercial potential.
• Current strategies focus on enhancing material performance and addressing scalability.

Conclusions:

• Non-intercalation cathodes are vital for advancing aqueous zinc battery technology.
• S, I₂, and Br₂ electrodes represent promising avenues for future commercialization.
• Further research should prioritize cathode optimization and addressing the lab-to-industry gap.