Mixed Ion Electron Conductor (MIEC) Cascade Electrodes for High Density Energy Storage in Li2O2

用于 Li2O2 高密度储能的混合离子电子导体 (MIEC) 级联电极

• 批准号: 1806059
• 负责人: Adam Holewinski
• 金额: $ 30.58万
• 依托单位: University of Colorado at Boulder
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-08-01 至 2022-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1806059&HistoricalAwards=false
• 关键词: Mixed; Ion; Electron; Conductor; MIEC

The lithium (Li)-air battery, with its potential energy density close to 1,700Wh/kg, is a promising battery solution for electric vehicles and renewable energy storage. In addition, light-weight and low-volume energy storage is crucial for a broad range of mobile power supply needs. This project will characterize a number of chemical processes that are relevant to storing energy using a reversible reaction between lithium and oxygen. The lithium-air battery system has the potential to be significantly lighter than conventional lithium-ion batteries of similar capacity. Current Li-air technology suffers from low efficiency and energy capacity. Battery cell design and operating conditions can be modified in ways to increase performance, but these conditions create a number of new complications, particularly with regard to materials durability. This project addresses a battery using solid materials (in contrast to conventional cells using organic liquid electrolytes). The research will determine the chemical nature and physical properties of various requisite solid-solid interfaces that can influence the viability of this battery design. The research will also provide fundamental knowledge of materials that are applicable to safer solid-state designs for conventional Li-ion batteries as well. Several educational outreach efforts will also be undertaken in this project. The PI will engage in a research experience for teachers (RET) program for local community college instructors for them to gain direct exposure to energy research and to incorporate related concepts into their curricula. Several undergraduate research internships will also be provided, and a series of educational web-modules related to batteries will be created.Li-O2 batteries have received recent attention due to their high theoretical energy density. To date these devices are still regarded as impractical due to the poor conducting character of the Li2O2 product (resulting in self-limiting discharge), as well as parasitic reactions with electrolyte solvents. This project will explore chemistries associated with a novel approach to raise the conductivity of Li2O2 through adjustments to operating conditions and doping. The approach utilizes an all-solid-state cell architecture. There is presently very little knowledge of the growth mechanisms and polarization behavior for the Li-O2 redox system under these conditions. The fundamental research will characterize charge carrier mobility, interfacial stability, and dopant chemistry with the aim of understanding how to engineer reversible, energy-dense storage systems based on Li-O2 redox. A key aspect of this work is a multi-faceted methodology for characterization of 'buried interfaces' between interacting solid materials, which are notoriously difficult to access. The project will utilize a combination of in-situ XPS, impedance spectroscopy, and cross-sectional aberration-corrected electron microscopy to characterize the properties of these interfaces and their evolution as a function of time, temperature, and polarization. While emphasis is placed on characterizing interfacial chemistries between Li2O2 and solid electrochemical materials, the methods and systems studied will yield insight that is transferrable to problems of broader interest in solid state ionics, particularly in the growing field of solid state Li-ion batteries.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.

锂（LI）空气电池的势能密度接近1,700WH/kg，是电动汽车和可再生能源存储的有前途的电池解决方案。此外，轻质和低体积的能源存储对于多种移动电源需求至关重要。该项目将表征许多与锂和氧气之间可逆反应储存能量相关的化学过程。锂空气电池系统的潜力比具有相似容量的传统锂离子电池明显轻。当前的Li-Air技术患有低效率和能源容量。电池电池设计和操作条件可以通过提高性能的方式进行修改，但是这些条件会产生许多新的并发症，尤其是在材料耐用性方面。该项目使用固体材料（与使用有机液体电解质的常规细胞相反）来解决电池。该研究将确定各种必要的固体界面的化学性质和物理性质，这些固体界面可能会影响该电池设计的可行性。这项研究还将提供有关适用于更安全的固态设计的材料的基本知识，这些材料也适用于常规锂离子电池。该项目还将进行一些教育外展工作。 PI将为当地社区大学教师提供教师（RET）计划的研究经验，以直接接触能源研究并将相关概念纳入其课程。还将提供一些本科研究实习，并将创建一系列与电池相关的教育网络模块。LI-O2电池由于其高理论能量密度而受到了最近的关注。迄今为止，由于LI2O2产物的传导特征（导致自限制放电）以及与电解质溶剂的寄生反应，这些设备仍然被认为是不切实际的。该项目将探索与一种新型方法相关的化学方法，以通过调整操作条件和掺杂来提高LI2O2的电导率。该方法利用了全稳态的细胞体系结构。目前，在这些条件下，LI-O2氧化还原系统的生长机制和极化行为的了解很少。基本研究将表征电荷载体的活动性，界面稳定性和掺杂化学性能，以了解如何基于LI-O2氧化还原来设计可逆的，能量浓缩的存储系统。这项工作的一个关键方面是一种多面方法，用于在相互作用的固体材料之间表征“埋入界面”的方法，而众所周知，这是难以访问的。该项目将利用原位XPS，阻抗光谱和横截面像差校正的电子显微镜的组合来表征这些接口的特性及其演变为时间，温度和极化的函数。虽然强调LI2O2和固体电化学材料之间的种族化学分配，但所研究的方法和系统将产生洞察力，这些洞察力可转移到对固态离子学更广泛兴趣的问题上，尤其是在固体状态李离子电池不断增长的领域，这反映了NSF的法定任务和综述的依据，这是通过评估的范围来进行的，这是通过评估的范围。

项目成果

Decomposition of Trace Li2CO3 During Charging Leads to Cathode Interface Degradation with the Solid Electrolyte LLZO

• DOI: 10.1002/adfm.202103716
• 发表时间: 2021-07-01
• 期刊: ADVANCED FUNCTIONAL MATERIALS
• 影响因子: 19
• 作者: Delluva, Alexander A.;Kulberg-Savercool, Jonas;Holewinski, Adam
• 通讯作者: Holewinski, Adam