Regulating Electrode-Electrolyte Interface via Patterned Solid Polymer Electrolytes for Solid-State Batteries

Despite the significant efforts devoted to solid-state battery research and the impressive performance improvement accomplished during the past two decades, a fundamental understanding of metal nucleation, growth, and interaction with solid electrolytes remains elusive. This research aims to bridge this knowledge gap by establishing a new electrolyte system to systematically decouple complex factors such as local mechanical, chemical, and electrochemical effects on lithium and sodium electrodeposition. The novel patterned solid polymer electrolytes (pSPEs) are designed to have micro-size features that can be used to understand the battery charging and discharging processes. This class of unique pSPEs is anticipated to allow for a detailed mechanistic study of metal nucleation and growth at the electrode/electrolyte interface. Thus, the research addresses a grand challenge facing the energy research community, and if successful, will lead to a new type of solid-state battery. The educational component of the project includes (1) developing class modules that will be used in graduate courses, (2) mentoring graduate and undergraduate students, and (3) involving high school students and teachers in the project’s research activities. This project aims to fabricate a series of spatially heterogeneous solid polymer electrolytes for solid-state batteries. The patterned solid polymer electrolytes (pSPEs), fabricated using soft lithography, will possess spatially controlled heterogeneity at the metal anode-electrolyte interface, which allows for systematically decoupling the convoluted local mechanical, chemical, and electrochemical effects on lithium (Li) and sodium (Na) electrodeposition in solid-state batteries. The specific aims are (1) fabricating pSPEs with controlled spatial heterogeneity in various properties using soft lithography; (2) understanding the nucleation mechanism of lithium and sodium metal at the electrode-pSPEs interface; (3) understanding the growth mechanism of lithium and sodium metal at the electrode-pSPEs interface. A library of pSPEs will be fabricated with controlled spatial heterogeneity varied from µm to >100 µm, selected based on the typical nucleation density of Li and Na. The pSPEs will serve as a new materials platform to investigate metal electrodeposition, and they will significantly improve fundamental understanding of the complex electrode/electrolyte interface in solid-state batteries. The knowledge gained from this project will benefit the next generation of battery design and pave the way for safer and more efficient energy storage solutions. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.