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

1437814 -Zdilla电池，可以有效地，负担得起和安全地与内燃机竞争，需要新的材料开发和设计策略。便携式消费者可充电锂离子电池的能量存储已达到~ 3.0Ah，不足以为电动车辆供电，但具有合理的30，000次充电/放电循环。使用金属锂作为阳极（以增加电池电压）和流通式阴极或其中氧被还原的阴极可以增加能量密度。用更便宜、更容易获得的钠替代锂将降低成本。然而，目前的高能量和功率密度Li电池技术受到安全问题和低温下性能差的困扰。用固体电解质取代液体电解质将提高安全性，低阻隔导电材料的发展将改善冬季行为。下一代锂电池，如锂空气和流通式阴极电池，已经设计有固体电解质（单独或与液体电解质组合）。在这里，这个多学科问题的一个方面将得到解决，即形成软固体晶体电解质与低亲和力通道的锂或钠离子传导。所有固态锂离子有机导体都具有增加的安全性的益处，但是具有差的离子电导率的限制，而陶瓷/玻璃导体具有较高的离子电导率，但是易碎并且可能具有差的对电极的粘附性。具有可以增强离子迁移的特定离子传导路径的固态有机材料的工程设计提供了实现更高固态离子电导率的手段的希望，而柔软的更具延展性的有机物将提供对电极的更好粘附。在这一领域只有有限的进展，使新的合成路线的发展，形成特定的结构与离子channels的一个重要avenue的research.Proposed是一个项目的设计和制造的一类新的固体电解质由锂盐共晶。所提出的材料具有离子通道，离子和通道壁之间的相互作用较弱。这些弱相互作用是由于在壁上故意使用可极化（软）官能团而产生的，根据皮尔逊硬软酸碱概念，这些官能团与不可极化（硬）锂离子的相互作用很差。所得材料将是具有良好导电性、降低的可燃性和改善的低温传导性的软固体。两种初步材料显示具有可忽略的激活势垒的锂离子传导，以及在室温和-78 ℃下的相等电导率。拟议工作的一个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的分子间相互作用的系统来实现，所述分子间相互作用通过π堆积或共价键来实现。由此产生的材料将是第一种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用于优化基质中阳离子的选择性传导。也将探索使用钠离子代替锂离子，以努力设计钠电池的电解质。将这些材料制成薄膜，用于器械试验。使用多面体低聚倍半硅氧烷聚乙二醇（POSS-PEG）作为粘合剂的初步结果是有前途的，并提供DC电导率的共晶之间的结，而不影响温度独立的behavior.Intellectual优点：所提出的一类材料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上级的性能，在低温下表现出超过优越性。这种材料有可能导致固态电池的设计，工作在所有范围内的全球温度，并拥有更高的安全性，由于没有挥发性易燃电解质。更广泛的影响：能源可再生能源是美国经济的一个越来越重要的部门。电池将在一段时间内继续在储能方面发挥重要作用。这项工作可能会产生新材料，以改善电池的安全性和功能，从而改善美国的能源独立性。更重要的是，该项目将培养年轻科学家，以满足市场对离子传导领域日益增长的需求，这与这个不断增长的经济部门的众多应用有关。

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.