| Popis: |
All-solid-state batteries (ASSBs), in which solid superionic conductors are used as electrolytes to transport ions between cathode and anode, have been regarded as one of the most promising candidates for the next-generation energy storage technologies in electric vehicles (EVs), grid applications, etc. The advances of ASSBs over conventional lithium-ion batteries (LIBs) come from their inherent safety and high energy density, which benefits from the use of nonflammable solid electrolytes (SEs) to potentially enable metal anodes (such as Li metal or Na metal) and high-voltage cathode active materials (CAM) in ASSBs. Since that, the research and design of SEs have been a hot topic to accelerate the development of ASSBs. At the same time, a good compatibility (e.g., chemical stability, electrochemical stability, and mechanical compatibility) between SEs and metal anodes/high-voltage cathodes are essential for achieving high-energy-density ASSBs with long cycle life. In this dissertation, the research towards SEs development and SE/electrodes interfacial protection have been studied. First, several new superionic conductors (Lix-3YIx, xLi2O-TaCl5, and xLi2O-HfCl4) with considerable Li-ion conductivity over 10‒3 S cm‒1 are developed, some of which are feasible in ASSBs with stable cycling performances. The novel structures those solids behave have been firstly discovered, deepening the fundamental understandings for ionic conductors. Then, by rational modifying an existing SE to possess high practical anodic limit, the stability between SE and high-voltage cathode can be achieved for high-voltage ASSBs. Finally, the concerns associated with active Na anode and SEs are addressed via applying functional molecular layer deposition (MLD) coatings. The results on SE synthesis, interfacial engineering, and mechanism studies in this dissertation shall pave the way to achieve high-performance all-solid-state Li-ion batteries, as well as guide the development for the beyond lithium battery technologies. |
