Polymer Electrolytes for Halide-ion Shuttle Batteries
Abstract
Advanced energy storage devices are needed to meet the critical energy needs of the United States and other nations. The ever-growing demand for high-performance portable electronics, aggressive pursuit of electric vehicles, and transition to renewable energy sources places significant pressure on the global resources for lithium-ion batteries (LIBs). Moreover, the geographic partitioning of resources needed to create LIBs makes it difficult to construct a secure, domestic pipeline in the United States. This has prompted new research efforts to look beyond lithium-ion into batteries based on other electroactive ions. The unifying feature undergirding all of these new systems is the reversible transport of electrochemically-active cations between the cathode and anode. A fundamentally different approach is to exploit anion-based shuttle batteries. Fluoride- and chloride-ion batteries are especially interesting given the excellent oxidative stability of FÐ and ClÐ, the potential for high gravimetric and volumetric energy densities, and competitive elemental abundances and distribution in earthÕs crust compared to lithium. Thus, halide-ion batteries have the potential to diversify the rechargeable battery portfolio. Halide-ion shuttle batteries, however, are a relatively young class of rechargeable batteries, and significant research effort is needed bring this field to maturation. Room temperature, solid-state halide-ion batteries are especially underdeveloped, with only a handful of notable studies that have established proof-of-concept. A major roadblock in developing all-solid-state halide-ion batteries is a lack of fundamental science on the relationship between ionic conductivity and the molecular-level interactions among the dissolved halide salts and the polymer host. This knowledge gap must be filled before any significant progress will be made in designing high-performance, halide-ion polymer electrolytes. Our proposal addresses this critical shortcoming through a combination of spectroscopic, computational, and structural studies of poly(ethylene oxide)-based electrolytes formulated for fluoride- and chloride-ion batteries. The work will be guided by successful scientific approaches employed in the development of LIB and sodium-ion battery polymer electrolytes, particularly the use of concerted spectroscopic and structural studies of crystalline solvates formed between salts and low-molecular ethylene oxides (ÒglymesÓ). We aim to isolate halide-salt and glyme solvates to generate a library of structural information that we can leverage when interpreting spectroscopic signatures of liquid-phase electrolyte solutions and high-molecular weight polymer electrolytes. This knowledge base will allow us to clarify relationships between charge delocalization on the cation and ionic association, cation-polymer interactions, and ion transport. We further aim to address how molecular additives frequently used to boost polymer electrolyte performance impact global and local structure in halide-ion polymer electrolytes and influence ion transport. Our work will provide the crucial datasets needed to guide the development of all-solid-state halide-ion batteries. A broader impact of this proposal is addressing the severe underrepresentation of Native Americans and women in the chemical sciences, especially in fields that are relevant to this funding agency. We propose a two-pronged approach to stimulate interest in these career paths. First, undergraduate students will participate in all aspects of this research program. Immersive learning through research is a powerful tool for stimulating interest in research-intensive careers. Second, a new course devoted to current challenges and opportunities in energy materials will be created and implemented at the host minority-serving institution. The course will go beyond traditional lectures by inviting students to engage the primary literature. Here they will learn the fundamental scienc
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jul 28, 2023
- Source ID
- W911NF2310264
Entities
People
- Christopher M Burba
Organizations
- Army Contracting Command
- Northeastern State University
- Office of the Secretary of Defense