Metal-Organic Frameworks based membranes for gas separation in Li-air batteries

基于金属有机框架的锂空气电池气体分离膜

• 批准号: 2443948
• 金额: --
• 依托单位: University of Nottingham
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2020
• 资助国家: 英国
• 起止时间: 2020 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2443948
• 关键词: Metal; Organic; Frameworks; based; membranes

Modern lithium-ion (Li-ion) batteries are rapidly reaching their own limits in terms of performance, and many doubts have been raised regarding their sustainability due to required resources including transition metals such as cobalt for the cathodes. More than 60% of the world's cobalt supply comes from the Democratic Republic of Congo (DRC), and a series of reports have shown that cobalt mining comes along with human rights abuses, unsafe mining, and several other risks. For a renewable energy transition, we need to minimize the social and environmental cost of batteries, therefore there is a real incentive to develop advanced sustainable battery types that exceed the energy storage performance of present Li-ion batteries. Li-air batteries, a novel type of next-generation technology, can address the issues above-mentioned. Unlike Li-ion, Li-air batteries are not based on the mechanism of ion insertion of Co-based cathodes, as the electrode is lithium metal and air acts as the cathode material. Additionally, in Li-air batteries O2 acts as the active material storing electric charge, so in principle the battery has a higher energy density, lower cost and potentially less toxicity compared with Li-ion technologies. In practice, however, designing a viable rechargeable Li-air device has proven extremely challenging. One of the greatest challenges is to avoid carbon dioxide entry into the cell as this can be detrimental to cell performance, due to the formation of insoluble by-products, such as Li2CO3. Proposed solution and methodology A novel solution proposed in this project involves using Mixed Matrix Membranes (MMMs) constructed from polymers and metal-organic framework (MOF) fillers to capture CO2 from air, preventing it from entering the cell. MMMs have the potential to achieve higher selectivity and permeability relative to the pure polymeric membranes, resulting from the addition of MOFs thanks to their inherent superior gas separation characteristics. At the same time, the fragility inherent of inorganic membranes may be avoided by using a flexible polymer as the continuous matrix. The final membranes will be composed of a highly oxygen permeability polymer phase, that ensures a proper oxygen flow inside the battery, and dispersed MOF particles (up to 50% weight of the final membrane) with high carbon dioxide selectivity and adsorption capacity. Structure-property-performance relationships will be used to optimize gas separation. Modern lithium-ion (Li ion) batteries are rapidly reaching their own limits in terms of performance, and many doubts have been raised regarding their sustainability due to required resources including transition metals such as cobalt for the cathodes. More than 60% of the world's cobalt supply comes from the Democratic Republic of Congo (DRC), and a series of reports have shown that cobalt mining comes along with human rights abuses, unsafe mining, and several other risks. For a renewable energy transition, we need to minimize the social and environmental cost of batteries, therefore there is a real incentive to develop advanced sustainable battery types that exceed the energy storage performance of present Li ion batteries. Li-air batteries, a novel type of next generation technology, can address the issues above-mentioned. Unlike Li ion, Li air batteries are not based on the mechanism of ion insertion of Co based cathodes, as the electrode is lithium metal and air acts as the cathode material. Additionally, in Li-air batteries O2 acts as the active material storing electric charge, so in principle the battery has a higher energy density, lower cost and potentially less toxicity compared with Li-ion technologies. In practice, however, designing a viable rechargeable Li air device has proven extremely challenging. One of the greatest challenges is to avoid carbon

现代锂离子（Li-ion）电池在性能方面正在迅速达到其自身极限，并且由于所需的资源（包括用于阴极的钴等过渡金属）而对其可持续性提出了许多疑问。全球60%以上的钴供应来自刚果民主共和国（DRC），一系列报告显示，钴矿开采伴随着侵犯人权、不安全开采等多种风险。对于可再生能源转型，我们需要最大限度地减少电池的社会和环境成本，因此有真正的动力去开发超越现有锂离子电池储能性能的先进可持续电池类型。锂空气电池是一种新型的下一代技术，可以解决上述问题。与锂离子电池不同，锂空气电池并非基于钴基阴极的离子嵌入机制，因为电极是锂金属，空气作为阴极材料。此外，在锂空气电池中，氧气充当存储电荷的活性材料，因此原则上与锂离子技术相比，该电池具有更高的能量密度、更低的成本和潜在的毒性更小。然而，在实践中，设计可行的可充电锂空气设备已被证明极具挑战性。最大的挑战之一是避免二氧化碳进入电池，因为这可能会由于形成不溶性副产物（例如 Li2CO3）而损害电池性能。提议的解决方案和方法 该项目提出的新颖解决方案涉及使用由聚合物和金属有机框架 (MOF) 填料构建的混合基质膜 (MMM) 来捕获空气中的二氧化碳，防止其进入细胞。由于添加了 MOF，MMM 具有固有的优异气体分离特性，因此相对于纯聚合物膜，MMM 有可能实现更高的选择性和渗透性。同时，通过使用柔性聚合物作为连续基质可以避免无机膜固有的脆性。最终的膜将由高透氧性聚合物相和分散的 MOF 颗粒（最多占最终膜重量的 50%）组成，确保电池内部有适当的氧气流动，具有高二氧化碳选择性和吸附能力。结构-性能-性能关系将用于优化气体分离。 现代锂离子电池在性能方面正在迅速达到其自身极限，并且由于所需的资源（包括用于阴极的钴等过渡金属）而对其可持续性提出了许多疑问。全球60%以上的钴供应来自刚果民主共和国（DRC），一系列报告显示，钴矿开采伴随着侵犯人权、不安全开采等多种风险。对于可再生能源转型，我们需要最大限度地减少电池的社会和环境成本，因此有真正的动力去开发超越现有锂离子电池储能性能的先进可持续电池类型。锂空气电池是一种新型的下一代技术，可以解决上述问题。与锂离子不同，锂空气电池并非基于钴基阴极的离子插入机制，因为电极是锂金属，空气作为阴极材料。此外，在锂空气电池中，氧气充当存储电荷的活性材料，因此原则上与锂离子技术相比，该电池具有更高的能量密度、更低的成本和潜在的毒性更小。然而，在实践中，设计一种可行的可充电锂空气设备已被证明极具挑战性。最大的挑战之一是避免碳排放