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.

锂空气电池的潜在能量密度接近1700 wh /kg，是一种很有前途的电动汽车和可再生能源存储电池解决方案。此外，轻量化和小体积的能量存储对于广泛的移动电源需求至关重要。该项目将描述一些化学过程，这些过程与利用锂和氧之间的可逆反应储存能量有关。与同等容量的传统锂离子电池相比，锂-空气电池系统具有显著轻量化的潜力。目前的锂-空气技术存在效率和能量容量低的问题。电池的设计和操作条件可以通过各种方式进行修改以提高性能，但这些条件会产生许多新的复杂性，特别是在材料耐用性方面。该项目解决了使用固体材料的电池（与使用有机液体电解质的传统电池相反）。这项研究将确定各种必要的固体-固体界面的化学性质和物理性质，这些界面会影响这种电池设计的可行性。这项研究还将为传统锂离子电池更安全的固态设计材料提供基础知识。在这个项目中还将进行几项教育推广工作。PI将参与当地社区大学教师的研究经验（RET）计划，使他们直接接触能源研究，并将相关概念纳入他们的课程。还将提供几个本科生研究实习机会，并将创建一系列与电池相关的教育网络模块。锂氧电池由于其较高的理论能量密度而受到近年来的关注。迄今为止，由于Li2O2产品的导电性差（导致自限放电）以及与电解质溶剂的寄生反应，这些装置仍然被认为是不切实际的。该项目将探索与通过调整操作条件和掺杂来提高Li2O2电导率的新方法相关的化学。该方法采用全固态电池架构。目前对Li-O2氧化还原体系在这些条件下的生长机制和极化行为知之甚少。基础研究将表征电荷载流子迁移率，界面稳定性和掺杂化学，目的是了解如何设计基于Li-O2氧化还原的可逆能量密度存储系统。这项工作的一个关键方面是一个多方面的方法来表征相互作用的固体材料之间的“埋藏界面”，这是众所周知的难以访问。该项目将结合使用原位XPS、阻抗谱和截面像差校正电子显微镜来表征这些界面的性质及其随时间、温度和极化的演变。虽然重点放在表征Li2O2和固体电化学材料之间的界面化学，但所研究的方法和系统将产生可转移到固态离子学中更广泛感兴趣的问题的见解，特别是在固态锂离子电池的不断发展的领域。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

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