Invited Speaker
Biography
Prof. Chunyi ZHI obtained B.S. degree in Physics from Shandong University and Ph.D. degree in condensed matter physics from Institute of Physics, Chinese Academy of Sciences. After two years’ postdoc in National Institute for Materials Science (NIMS) in Japan, he was promoted to be ICYS researcher, researcher (faculty) and senior researcher (permanent position) in NIMS. Dr. Zhi is now a professor in MSE, CityU. Dr. Zhi has extensive experiences in flexible energy storage, aqueous electrolyte batteries, zinc ion batteries and highly thermally conducting insulating polymer composites. He has published more than 400 papers with an h-index of 105 and other-citation of ~39000 (ISI). He has been granted more than 100 patents. Dr. Zhi is a recipient of the outstand research award and the President’s Award City University of Hong Kong, NML researcher award, and Beijing Science and Technology Award (first class). He is Clarivate Analytics Global highly cited researcher (2019-2022, Materials Science), RSC fellow and member of The Hong Kong Young Academy of Sciences.
Stable Zn Anode and High Energy Cathodes for Aqueous Zn Batteries
Chunyi ZHI
Abstract
Development of energy storage system in the past year focus on improvement of energy density. While the progress is remarkable, safety problems of lithium-ion batteries (LIB) have been intensively exposed. On one hand, LIB is not intrinsically safe with very active anode, flammable electrolyte and oxygen-releasing cathode; on the other hand, many application scenarios actually don’t require very high energy density.
Numerous reports of extremely stable Zn anode judged from the symmetrical cells have been published, which remarkably deviated from data of the asymmetrical or full cells in terms of accumulated cycling lifetime. After a thorough analysis, we conclude that soft short circuit, which cannot be distinguished by the widely used galvanostatic cycling tests, prevails in a plethora of reported Zn anodes and leads to a super-stable illusion. Then we propose several pertinent test protocols that can be combined with galvanostatic cycling test to evaluate a symmetric cell and characterize the stability of a Zn anode. In particular, the R0ct measured at a low current density and the Ea of the stripping/plating reactions can be two complementary indicators for the occurrence of SS, thereby avoiding misjudgment of the Zn anode stability. The comprehensive understanding of SS in this work can be a good start to inspire more rational and reliable endeavors toward the Zn anode research. Since other metal anodes (Li, Na, K, Mg et.al) share similarities in electrochemical behaviors, the proposed protocols in this commentary can also be extended for reporting reliable results in those research fields.
References
[1] Zhao, Y et al., Nature Communications 13, 752 (2022)
[2] Li, Q. et al., Nature Communications 13, 3699 (2022)
[3] Chen, Z. et al. Chem 8, 2204 (2022)
[4] Li, X. et al. Nature Review Chemistry 6, 389 (2022)