News Resource: School of Materials Science

and Engineering

Editor: News Agency of BIT

Translator: Li Wenlin, News Agency of BIT

Recently, the research team of Bai Ying, the professor of the School of Materials Science of BIT, has made great progress in the negative electrode protection of aqueous zinc batteries. On the fourth of January, the relevant research results were published in Advanced Energy Materials, an international top journal of materials, with the title of "Stabilizing Zn Metal Anodes via Cation/Anion Regulation wards High Energy Density Zn-Ion Batteries". Professor Bai Ying and Professor Wu Chuan, the School of Materials of BIT, are the co-correspondents of this paper. Zhao Ran, a post doctor, is the first author.

Aqueous zinc ion batteries (AZBs) are strong competitors of the next generation of large-scale energy storage technology and important ways to serve the "double carbon" strategy to realize "new energy + energy storage", owing to its high safety, low cost, and environmental friendliness. Due to the abundant reserves of zinc resources in China, the high theoretical capacity of the metal and the appropriate electrode potential, zinc metal has been widely concerned in the field of negative electrode. However, zinc deposition and stripping are accompanied by side reactions such as passivation, corrosion and hydrogen evolution, and dendrite growth caused by uneven zinc deposition, leading to battery capacity decay, low coulomb efficiency and limited life.

Pointing at this problem, the research team of Professor Bai Ying of BIT has used microporous materials with same three-dimensional aperture as the artificial interface layer. By simultaneously adjusting the cation and anion currents, the occurrence of side reactions is inhibited and the uniform deposition of zinc ions is achieved. According to the experimental results, DFT and COMSOL theoretical simulation calculations, microporous zeolite effectively blocks the aggregation of sulfate radical in the electrolyte on the surface of zinc metal, thus inhibiting the formation of Zn4 (OH) 6SO4 · xH2O; the use of zeolites homogenizes the zinc ion current and electric field distribution on the anode surface, and at the same time, the interaction between oxygen element in its skeleton and zinc ion induces the deposition of dendrite-free zinc (002); the negatively charged zeolite molecular sieve skeleton attracts zinc ions in the solvent through electrostatic action, which weakens the concentration polarization on the negative side and reduces the over-potential of the electrode. The specific experimental results and ion transport mechanism are shown in Figure 1.

Fig 1. diagrammatic sketch of study on the protective function of zeolite molecular sieve and ion transport

Because of the multiple functions of the protective layer, the performance of the modified zinc anode has been greatly improved. The symmetrical battery achieves 2400 hours of long cycle (5 mA cm-2/2 mAh cm-2), more than 500 hours of deep zinc deposition/stripping and high current density (100 mAh cm-2) tolerance; the full battery assembled with manganese dioxide shows excellent performance (as shown in Figure 2), produces less side reaction products during charging and discharging, shows low interface resistance, and achieves a capacity retention of 76.4% after 7500 cycles; the anode-free battery constructed with this protective layer shows a high energy density of 192.8 Wh-kg-1 (based on the mass of all active electrode materials in the full battery). The above results provide a new research idea for the protection strategy of zinc metal anode. The use of zeolite with excellent performance, low cost, environmental protection and mature industrial manufacturing technology as artificial interface is conducive to the development of commercial long-life zinc anode, and promote the practical application of aqueous zinc ion batteries.

Fig 2. positive effect of artificial interface layer on the performance of full battery

Paper link:https://doi.org/10.1002/aenm.202203542

Brief introduction of the authors:

Zhao Ran, a postdoctoral student of the School of Materials Science and Engineering, obtained doctorate at Arizona State University in 2017. Zhao has mainly engaged in the preparation, performance and mechanism research of key materials for multivalent metal ion batteries, including zinc ion batteries, calcium ion batteries and aluminum ion batteries, and has already published 21 papers included in SCI, applied for 5 patents, presided over the National Natural Science Foundation Youth Program and the post-doctoral program.

Wu Chuan, professor, doctoral supervisor, national high-level talent, associate editor of Energy Material Advanced, a science cooperation journal. He has mainly engaged in energy storage and conversion systems and their key materials, including lithium ion batteries, sodium ion batteries, aluminum secondary batteries and other high-performance secondary battery new systems. He has presided over the national 973 project, the National Natural Science Foundation of China, the key research projects of Beijing Natural Science Foundation, and the doctoral program fund of the Ministry of Education.

Bai Ying, professor, doctoral supervisor, member of the Royal Society of Chemistry and a new century talent of the Ministry of Education. She has engaged in the research of advanced secondary batteries, light hydrogen storage and other new energy storage materials, mainly including the key materials of lithium/sodium/zinc batteries and other systems, the interface stability of electrodes and electrolyte, thermal analysis and thermal safety of batteries and other basic scientific issues. She has presided over projects such as the National 863 Program, the National Natural Science Foundation, the National Basic Research and Development Project, and the National Major Special Project.