ERI: Unravel Charge Transfer Mechanisms in the Bulk and at Interphases and Interfaces of Ionogel Solid Electrolytes for High-Power-Density All-Solid-State Li Metal Batteries

这是NSF工程研究启动奖。利用固态电解质沿着锂金属阳极的全固态电池因其改进的安全性和同时实现高能量、功率和寿命的潜力而引人注目。通过将离子液体限制在离子导电聚合物和/或陶瓷内形成的离子凝胶显示出作为固体电解质的有利性质的独特组合。然而，它们可实现的功率密度和循环稳定性仍然明显较差，主要是由于缺乏对锂离子传输机制的理解。该项目将开发一系列设计的三相离子凝胶系统，其中每个阶段将被修改以促进快速锂离子传输。对机理的理解将阐明真正的锂离子传输路径和曲折度，指导高性能固态电池的离子凝胶基固体电解质和中间层的结构和化学设计。此外，该项目将整合研究和教育，以促进STEM领域的跨学科学习。能源储存和转换技术的教育将提高人们对碳中和的认识，并激励年轻一代探索更可持续发展的未来的技术解决方案。本提案的目标是阐明三元离子凝胶固体电解质中不同亲石环境相互作用影响的局部锂离子传输机制。亲石分子环境将通过由离子液体组成的三元离子凝胶平台来创建，其中移动的阴离子可以与Li离子配位，用不同的亲石基团官能化的聚合物支架，其与Li离子弱配位以用于快速Li离子跨聚合物相和沿着聚合物相传输，以及用亲石配体接枝的陶瓷纳米填料，用于沿着陶瓷相的简易Li离子传输。这些机理的理解将阐明a）Li阳离子和亲石阴离子之间的缔合和解离类型以及它们之间的竞争或合作相互作用：B）不同本征界面处Li离子的真实解离和Li离子的传输，这将决定具有不同本征界面的三元离子凝胶固体电解质中Li离子的有效传输路径和曲折度;和c）通过接枝到陶瓷相的功能配体有效地固定阴离子，从双离子传导体系转化为单离子传导体系。机制的见解将提供设计原则，通过设计有利的亲石分子环境，调节和加速锂离子在各种界面和接口的传输。该研究具有潜在的变革性影响，可以提供关键的见解，并指导未来的研究工作，以实现高功率密度和高能量密度全固态电池的离子凝胶固体电解质和中间层的可规模化生产。该奖项反映了NSF的法定使命，并被认为值得通过使用基金会的知识价值和更广泛的影响审查标准进行评估来支持。

This is an NSF Engineering Research Initiation award. All-solid-state batteries utilizing solid state electrolytes along with Li-metal anode are notable for their improved safety and potential to achieve simultaneously high energy, power, and longevity. Ionogels, formed by confinement of ionic liquids within ionic conductive polymers and/or ceramics, show a unique combination of favorable properties as solid electrolytes. However, their achievable power density and cycling stability remains notably inferior, owing primarily to the lack of understanding of Li-ion transport mechanisms. The project will develop a series of designed three-phase ionogel systems where each phase will be modified to promote fast Li-ion transport. The mechanistic understanding will elucidate the true Li-ion transport path and tortuosity, guiding the design of structure and chemistry of ionogel-based solid electrolytes and interlayers for high performance solid-state batteries. In addition, this project will integrate research and education for fostering interdisciplinary learnings in STEM areas. Education in Energy Storage and Conversion technology will raise more awareness of carbon neutrality and inspire younger generations to explore technical solutions for a more sustainable future.The goal of this proposal is to elucidate the local Li-ion transport mechanisms influenced by the interaction of different lithophilic environments within ternary ionogel solid electrolytes. The lithophilic molecular environments will be created through ternary ionogel platforms composed of ionic liquid where moving anions can coordinate with Li-ions, polymer scaffolds functionalized with different lithophilic groups which weakly coordinate with Li-ions for rapid Li-ion transport across and along the polymer phase, as well as ceramic nanofillers grafted with lithophilic ligands for facile Li-ion transport along the ceramic phase. These mechanistic understandings will elucidate a) the types of association and dissociation between Li cations and lithophilic anions and the competitive or cooperative interaction between them; b) the true Li-ion dissociation and Li-ion transport at different intrinsic interphases, which will determine the efficient Li-ion transport pathways and tortuosity within the ternary ionogel solid electrolyte featuring diverse intrinsic interphases; and c) the conversion from bi-ion conducting to single-ion conducting systems through effective immobilization of anions by the functional ligands grafted to the ceramic phase. The mechanistic insights will provide the design principles for regulating and accelerating Li-ion transport at various interphases and interfaces through the design of favorable lithophilic molecular environments. The research has potentially transformative impact for offering crucial insights and steering future research efforts toward scalable production of ionogel solid electrolytes and interlayers for high-power-density and high-energy-density all solid-state batteries.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.