Moldable, self-healing, highly conductive organic co-crystalline solid electrolytes for safer lithium ion batteries

非技术概述对于这个项目，由材料研究部固体和材料化学项目支持，教授们的研究小组。坦普尔大学的兹迪拉和文德正在开发一种用于锂离子电池的新型固体电解质隔膜。目前的锂离子电池技术依赖于使用易燃和潜在爆炸性的液体电解液，这已导致移动设备、电动汽车和其他应用中的电池起火和爆炸。固体、易燃性极低的替代品的开发将提高这些设备的安全性。然而，目前研究的许多固体电解质表现出较差的性能或与现有的电池化学不相容。凭借这一奖项，首席研究人员合成和研究软固体共晶电解质(即结合两个或两个以上分子组分但形成统一晶体结构的电解质)，以了解能够实现更高功率性能并承诺与现有和下一代电池组件兼容的基础材料化学。研究人员还使用计算工具来更好地理解这些由有机骨架分子和锂离子源组成的新组合，并表征它们的电化学性质。该项目服务于国家利益，建立了一项基本理解，使技术能够提高电池的安全性和性能，电池是移动设备、交通运输和清洁能源技术中越来越核心的组成部分。安全、高功率、高能电池技术的实现为太阳能储存和减少运输使用化石燃料提供了一条途径，这两者都为美国提供了更大的能源独立性，并为气候健康减少碳足迹提供了一种手段。此外，这项研究在全国最多样化的学校之一培养下一代科学家，并为代表不足的群体服务，效果很好。技术总结。对于这个项目，由材料研究部固体和材料化学计划支持，教授的研究小组。坦普尔大学的兹迪拉和文德开发了一种用于锂离子电池的新型固体电解质隔膜。电池电解液研究的进展是渐进的，基本上归因于液体有机体系、固体聚合物和固体陶瓷的改性。在这项工作下研究的新型固体电解质有可能比其他固体有机电解质具有更好的导电性，同时表现出比当前市场标准液体更好的电压稳定性和电极稳定窗口。研究人员从基础研究的角度研究了这种材料的新颖机械物理性能，包括形成促进自我修复的表面液层。虽然表面液-固平衡的概念是已知的(就像在水-冰的经典例子中一样)，但这一性质从未被应用于电解液材料，因此代表着一个获得基本见解的机会。本论文的主要研究内容为：1.优化电导率和锂离子迁移数(TLI)的离子基共晶体的制备和表征。这是通过最大化阳离子的迁移率同时最小化阴离子的迁移率来实现的，这是通过设计与阴离子而不是与阳离子强烈相互作用的基质来实现的。2：电化学性能和机械/热性能的评价。这是通过使用X射线衍射、电化学分析(电化学阻抗谱、循环伏安法、线性扫描伏安法和循环研究)、热分析(DSC、TGA)和电子显微镜的尸检分析来实现的。3：使用分子动力学和量子分子计算对离子传导的物理性质和机制进行建模。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Non-Technical SummaryFor this project, supported by the Solid State and Materials Chemistry program in the Division of Materials Research, the research groups of Profs. Zdilla and Wunder at Temple University are developing a new class of solid electrolyte separators for lithium-ion batteries. Current lithium-ion battery technology relies on the use of a flammable and potentially explosive liquid electrolyte which has led to battery fires and explosions in mobile devices, electric vehicles, and other applications. The development of solid, minimally flammable replacements would enhance the safety of these devices. However, many currently investigated solid electrolytes exhibit poor performance or incompatibility with existing battery chemistry. With this award, the principal investigators synthesize and study soft-solid co-crystalline electrolytes (i.e. electrolytes that combine two or more molecular components but form a uniform crystalline structure) to understand the fundamental materials chemistry that could enable higher-power performance and promise compatibility with existing and next-generation battery components. The researchers also use computational tools to better understand these materials that consist of new combinations of organic framework molecules and lithium-ion sources and characterize their electrochemical properties. The project serves the national interest by developing a fundamental understanding that enables technologies to improve the safety and performance of batteries, an ever-more central component of technology in mobile devices, transportation, and clean energy. Realization of safe, high-power, high-energy battery technology provides a path toward solar energy storage and decreased use of fossil fuels for transportation, both of which provide greater energy independence for the United States, and a means to decrease carbon footprint for the health of the climate. Further, this research serves to train the next generation of scientists at one of the most diverse schools in the country and serves underrepresented groups with great effect.Technical Summary.For this project, supported by the Solid State and Materials Chemistry program in the Division of Materials Research, the research groups of Profs. Zdilla and Wunder at Temple University develop a new class of solid electrolyte separators for lithium-ion batteries. Progress in battery electrolyte research has been incremental and essentially relegated to modifications of liquid organic systems, solid polymers, and solid ceramics. The new class of solid electrolytes investigated under this effort has the potential to enable better conductivity than other solid organic electrolytes, while at the same time exhibiting better voltage stability and electrode stability windows than liquids, the current market standard. The researchers investigate the materials’ novel mechanophysical properties from a fundamental research perspective, including a developing a surface liquid layer that facilitates self-healing. While the concept of a surface liquid-solid equilibrium is known (as in the classic example of water-ice), this property has never been applied to electrolyte materials, and thus represents an opportunity for fundamental insights. The objectives of the research are: 1: Preparation and characterization of ion-matrix cocrystals with optimized conductivity and lithium-ion transference numbers (tLi+). This is achieved by maximizing the mobility of the cation while minimizing the mobility of the anion, which is achieved by designing matrices that interact strongly with the anion, but not with the cation. 2: Evaluation of electrochemical performance and mechanical/thermal properties. This is achieved using characterization using X-ray diffraction, electrochemical analysis (electrochemical impedance spectroscopy, cyclic voltammetry, linear sweep voltammetry, and cycling studies), thermal analysis (DSC, TGA), and post-mortem analysis by electron microscopy. 3: Modelling the physical properties and mechanism of ion conduction using molecular dynamics and quantum molecular computation.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.