SusChEM: Molecular organic frameworks for solid state ion channels with exceedingly simple design: Toward barrier-less ion migration

能有效、实惠和安全地与内燃机竞争的1437814-Zdila型电池需要新材料开发和设计策略。便携式可充电锂离子电池的储能已达到~3.0ah，不足以为电动汽车提供动力，但具有合理的30,000次充放电循环。使用金属锂作为阳极(以增加电池电压)和流过的阴极或其中氧被还原的阴极，可以增加能量密度。用更便宜、更容易获得的钠取代锂将降低成本。然而，目前的高能量和高功率密度锂电池技术存在安全问题和低温性能差的问题。用固体电解质取代液体电解质将提高安全性，而低阻隔性导电材料的开发将改善冬季行为。下一代锂电池，如锂、空气和直通式正极电池，已经设计出使用固体电解液(单独或与液体电解液结合)。在这里，这个多学科问题的一个方面将被解决，即形成具有低亲和力的锂离子或钠离子传导通道的软固体晶体电解质。所有固态锂离子有机导体都具有增加安全性的优点，但存在离子导电性差的局限性，而陶瓷/玻璃导体具有较高的离子导电率，但很脆，与电极的附着力较差。具有特定离子传导路径的固态有机材料的工程可以增强离子迁移，这为获得更高的固态离子电导率提供了希望，而柔软、更具延展性的有机材料将提供更好的电极粘附性。这方面的研究进展有限，开发新的合成路线以形成具有离子通道的特定结构是一个重要的研究途径。提出了一种由锂盐共晶体制成的新型固体电解质的设计和制备项目。所提出的材料具有离子通道，离子与通道壁之间的相互作用很弱。这些弱相互作用是由于故意在墙壁上使用可极化(软)功能，根据皮尔逊硬软酸碱概念，这些功能与不可极化(硬)锂离子相互作用很差。由此产生的材料将是具有良好导电性、降低易燃性和改善低温传导性的软固体。两种初步材料显示锂离子电导具有可忽略的活化势垒，在室温和-78℃下的电导率相等。拟议工作的主要目标是提高原型材料在高温下的热稳定性。这将通过开发具有更大分子间相互作用的体系来实现，这些体系通过圆周率堆积或共价键来实现。由此产生的材料将是第一个在整个全球温度范围内具有良好导电性的固体电解质。阴离子大小和基质亲和力的变化将被用来优化阳离子在基质中的选择性传导。还将探索使用钠离子取代锂离子，以努力设计钠电池的电解液。这些材料将被制成薄膜，用于器件测试。利用多面体低聚倍半硅氧烷聚乙二醇(POSS-PEG)作为粘结剂的初步结果是有希望的，并在不影响温度无关行为的情况下提供了共晶之间的直流电导连接。智能优点：所提出的材料类别代表了一类新的固体电解质材料。它们在室温下表现出比纯聚合物电解质稍好的性能，而在低温下表现出更大的优越性。这种材料有可能导致固态电池的设计，这种电池可以在全球所有温度范围内工作，而且由于没有挥发性易燃电解液，安全性可能会提高。广泛的影响：能源可再生能源在美国经济中越来越重要。在一段时间内，电池将继续在储能方面发挥主要作用。这项拟议的工作可能会带来新的材料，用于改善电池的安全性和功能，以改善美国的能源独立性。更重要的是，该项目将培训年轻科学家，以满足市场在离子传导领域日益增长的需求，离子传导领域与这个不断增长的经济部门的许多应用有关。

1437814 - ZdillaBatteries that can effectively, affordably and safely compete with the internal combustion engine require new materials development and design strategies. Energy storage in portable consumer rechargeable lithium ion batteries has reached ~ 3.0 Ah, insufficient for powering electric vehicles, but with reasonable, 30,000, charge/discharge cycles. The use of metallic lithium as the anode (to increase the cell voltage) and flow-through cathodes or cathodes in which oxygen is reduced, can increase energy density. Replacement of lithium with less expensive, more available sodium will reduce costs. However, current high energy and power density Li battery technology suffers from safety concerns and poor performance at low temperatures. Replacement of liquid electrolytes with solid electrolytes will improve safety, and development of low-barrier conducting materials will improve wintertime behavior. Next generation lithium batteries such as lithium air and flow-through cathode batteries have already been designed with solid electrolytes (alone or in combination with liquid electrolytes). Here, one aspect of this multidisciplinary problem will be addressed, namely the formation of soft solid crystal electrolytes with low-affinity channels for lithium or sodium ion conduction. All solid-state lithium ion organic conductors have the benefits of increased safety, but the limitation of poor ionic conductivity, while ceramic/glass conductors have higher ionic conductivities but are brittle and can have poor adhesion to the electrodes. Engineering of solid-state organic materials with specific ion conduction pathways that can enhance ion migration offers promise as a means to achieve higher solid-state ionic conductivities, while soft, more malleable organics will afford better adhesion to the electrodes. There is only limited progress in this area, making the development of new synthetic routes for the formation of specific architectures with ion channels an important avenue of research.Proposed is a project on design and fabrication of a novel class of solid electrolytes made from lithium salt cocrystals. The proposed materials posess ion channels with weak interactions between the ions and channel walls. These weak interactions arise from the deliberate use of polarizable (soft) functionality on the walls, which interact poorly with the non-polarizable (hard) lithium ions according to the Pearson Hard Soft Acid Base Concept. The resulting materials will be soft solids with good conductivity, decreased flamability, and improved low-temperature conduction. Two preliminary materials show lithium ion conduction with negligible activation barrier, and equal conductivity at room temperature and -78 C. A major goal of the proposed work is to increase the thermal stability of prototype materials at high temperatures. This will be achieved by developing systems with greater intermolecular interactions through pi-stacking or covalent linkage. The resulting materials would be the first solid electrolytes to have favorable conductivities over the entire range of global temperatures. Variation of anion size and matrix affinity will be used to optimize the selective conduction of cations in the matrix. The use of sodium ions in place of lithium ions will also be explored in an effort to design electrolytes for sodium batteries as well. These materials will be fabricated into films for device testing. Preliminary results on the use of Polyhedral oligomeric silsesquioxane polyethylene glycol (POSS-PEG) as a binder are promising, and provide junctions between the cocrystals for DC conductivity without affecting the temperature independent behavior.Intellectual Merit :The proposed class of materials represent a new class of material for solid electrolytes. They exhibit behavior slightly superior to pure polymer electrolytes at room temperature, and exceeding superiority at low temperature. Such materials have the potential to lead to the design of solid state batteries that work across all ranges of global temperature, and posess increased safety due to the absence of volatile flammable electrolytes.Broader Impacts :Energy renewables is an increasingly important sector of the United States Economy. Batteries will continue to play a major role in energy storage for some time. The proposed work may lead to new materials for the improvement of safety and functioning of batteries for the betterment of US energy independence. More importantly, the project will train young scientists in order to supply the market's increasing demand in the field of ion conduction, which is relevant to numerous applications in this growing economic sector.