Abstract
Eutectic materials are emerging as a promising avenue for advanced energy storage and conversion technologies. Their unique phase diagrams and low melting points provide enhanced thermal and electrical conductivity, making them ideal for next-generation batteries, supercapacitors, and fuel cells. The ability to tune their composition optimizes electrochemical performance, leading to improved energy density and efficiency.Recent advancements focus on hybrid systems that combine multiple energy storage methods, maximizing overall efficiency. Additionally, exploring eutectic solvents in electrochemical processes has opened new pathways for designing safer and more effective electrolytes. As the demand for sustainable energy solutions grows, the development of eutectic materials is crucial for the transition to cleaner technologies, enhancing performance while supporting sustainability goals.
Non-metallic ammonium ion (NH4+) batteries are gaining attention due to their low cost, nontoxicity, and environmental sustainability. This study elucidates the solvation interactions between NH4+ and solvents, proposing design principles for NH4+ weakly solvated electrolytes. By selecting succinonitrile, a metal-free eutectic electrolyte (MEE) was constructed, significantly broadening the electrochemical stability window and improving charge transfer processes. The NH4-ion batteries exhibited a high energy density of 65 Wh kg–1 and long-term cycling performance.
The development of new ionic conductors for solid-state devices is also challenging. Hydrogen-bonded ionic co-crystals (HICs) showcase flexible structures with potential for cation transport channels. An optimized HIC achieved high ionic conductivity at room temperature and low temperatures while restraining dendrite growth during cycling. This HIC supports solid-state Zn||covalent organic framework cells and hybrid supercapacitors, demonstrating extraordinary rate capability.
Organic electrode materials, while abundant and environmentally friendly, often have low conductivities. This study introduces a crystal engineering strategy using thiourea to modify phenanthrenequinone, enhancing its conductivity and creating proton channels to improve reaction kinetics. The resulting Zn||PQ-TU batteries showed remarkable performance and long-term stability.
In summary, we have developed various eutectic materials that function as both electrolytes and electrode materials, significantly enhancing their application in electrochemistry and paving the way for innovative materials.
| Date of Award | 10 Mar 2025 |
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| Original language | English |
| Awarding Institution |
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| Supervisor | Chunyi ZHI (Supervisor) |