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

SusChEM：设计极其简单的固态离子通道的分子有机框架：实现无屏障离子迁移

• 批准号: 1437814
• 负责人: Michael Zdilla
• 金额: $ 55万
• 依托单位: Temple University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-07-15 至 2017-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1437814&HistoricalAwards=false
• 关键词: SusChEM; Molecular; organic; frameworks; solid

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.

1437814 - zdilla电池要想有效、经济、安全地与内燃机竞争，就需要新的材料开发和设计策略。便携式消费级可充电锂离子电池的储能已达到~ 3.0 Ah，不足以为电动汽车提供动力，但具有合理的3万次充放电循环。使用金属锂作为阳极（以增加电池电压）和流经阴极或氧减少的阴极，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锂电池技术存在安全问题和低温性能差。用固体电解质替代液体电解质将提高安全性，低阻隔导电材料的开发将改善冬季行为。下一代锂电池，如锂空气和流动阴极电池，已经被设计为固体电解质（单独或与液体电解质结合）。在这里，将讨论这个多学科问题的一个方面，即形成具有低亲和力通道的软固体晶体电解质，用于锂或钠离子传导。所有固态锂离子有机导体都有增加安全性的好处，但离子电导率差的限制，而陶瓷/玻璃导体具有更高的离子电导率，但很脆，与电极的粘附性差。具有特定离子传导途径的固态有机材料工程可以增强离子迁移，为实现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粘附到电极上。这一领域的进展有限，因此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。提出了一个设计和制造一类由锂盐共晶制成的新型固体电解质的项目。所提出的材料具有离子通道，离子与通道壁之间存在弱相互作用。根据皮尔逊硬软酸碱概念，这些弱相互作用是由于故意在壁上使用可极化（软）功能而产生的，这些功能与不可极化（硬）锂离子相互作用很差。所得到的材料将是具有良好导电性、降低可燃性和改善低温导电性的软固体。两种初步材料在室温和-78℃下具有可忽略的激活势垒的锂离子导电性，并且具有相等的导电性。提出的工作的主要目标是增加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，通过pi堆叠或共价键。由此产生的材料将是第一个在整个全球温度范围内都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。在设计钠电池电解质的过程中，也将探索用钠离子代替锂离子的方法。这些材料将被制成薄膜用于设备测试。初步结果表明，使用多面体低聚硅氧烷聚乙二醇（POSS-PEG）作为粘合剂是有希望的，并且在不影响温度无关行为的情况下为直流电导率提供了共晶之间的连接。知识优势：提出的材料类别代表了固体电解质材料的新类别。它们在室温下表现出略优于纯聚合物电解质的行为，在低温下表现出更大的优势。这种材料有可能导致固态电池的设计，可以在全球所有温度范围内工作，并且由于没有挥发性易燃电解质而具有更高的安全性。更广泛的影响：可再生能源是美国经济中日益重要的一个部门。在一段时间内，电池将继续在能源存储方面发挥重要作用。这项工作可能会为提高电池的安全性和功能带来新材料，从而改善美国的能源独立。更重要的是，该项目将培养年轻的科学家，以满足市场在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许多应用有关。