image: Design principles for boosting neutral ZABs performance via electrolyte and interface engineering
Credit: ©Science China Press
Neutral zinc-air batteries (ZABs) are highly desirable for future energy storage due to their intrinsic safety, low cost, and eco-friendliness. Yet, their potential has been hampered by fundamental performance issues, including sluggish oxygen reaction kinetics and poor stability at the electrode interface.
In a comprehensive Feature Article published in SCIENCE CHINA Chemistry, a team led by Professor Wei Sun and Dr. Sha Luo at the University of Electronic Science and Technology of China (UESTC) presents a robust solution: a systematic Multiscale Regulation Framework. The article, titled "Neutral zinc-air batteries: multiscale design of electrolytes and interfaces," consolidates years of the team’s original research, providing a unified methodology to optimize ZABs across all scales-from molecular interactions to device architecture.
The team’s framework is built upon four key pillars of innovation, each addressing a specific bottleneck:
- Optimizing Electrolyte Formulation: The team’s work introduced a low-cost, non-alkaline zinc acetate electrolyte. This innovation creates a mild, buffered environment that minimizes zinc corrosion and dendrite formation, enabling a highly reversible discharge-charge process.
- Controlling the Interfacial Microenvironment: By employing specific hydrophobic anions (OTf-), the researchers precisely tuned the electrode interface. This resulted in the discovery of a unique ZnO2-based non-protic oxygen reduction pathway, offering a major mechanistic advance for stabilizing electrochemical reactions in neutral media.
- Engineering Cathode Structure: The framework highlights the use of specialized cathode architectures, such as hierarchical porous carbon (HPC). This structural control effectively manages the discharge product (zinc hydroxyacetate, ZHA) and shifts the reaction pathway, leading to a significant increase in energy efficiency, reaching 74.5% in demonstrated devices.
- Implementing Hybrid Strategies: At the device level, the team introduced a hybrid zinc-air/Zn-MnO2 battery (ZAMB) design. This strategy leverages the in-situ formation of an MnO2 catalyst and utilizes a high-voltage redox reaction, synergistically boosting both the energy output and overall system efficiency.
The publication of this Feature Article provides more than just a summary; it serves as a comprehensive blueprint for addressing the remaining scientific challenges in neutral ZABs. The systematic approach developed by the UESTC team offers critical scientific guidance for accelerating the development of high-performance, safety, and durable next-generation energy storage solutions.