Collaborative Research: Engineering the Chemistry at Solid-Solid Interfaces of Li-O2 Battery Cathodes

合作研究：锂氧气电池正极固-固界面化学工程

• 批准号: 1935645
• 负责人: Jeffrey Greeley
• 金额: $ 25.29万
• 依托单位: Purdue University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1935645&HistoricalAwards=false
• 关键词: Collaborative; Research; Engineering; Chemistry; Solid

Lithium-oxygen batteries potentially could have energy storage capacities that rival gasoline fuel, but there remains much fundamental scientific knowledge to learn about these batteries before the technology can be commercialized. In particular, some of the chemical products formed during the operation of the batteries can slowly degrade and poison the materials, leading to performance losses over extended periods of operation. This research project seeks to overcome these problems by exploring a class of inexpensive, mixed metal oxide electrocatalysts that may alter the chemistry of lithium-oxygen batteries. This project aims to develop a framework to engineer the chemistry of lithium-oxygen batteries, which are a potential next-generation energy storage device, and to improve their performance. The studies combine advanced characterization methods and theoretical calculations to determine how the properties of the oxide surfaces influence the products that are produced on lithium-oxygen electrodes. These insights will be leveraged to develop design principles that will aide in identifying oxide electrocatalysts that improve battery cell performance. The researchers involved in this project will partner with local K-12 schools to involve economically disadvantaged students with the proposed research through summer internships and student exchanges. They aim to inspire the students to pursue careers in science and engineering. A fundamental understanding of the reactions occurring at solid-solid interfaces is critical for the development of next-generation energy storage devices, such as lithium-oxygen batteries. Lithium-oxygen batteries have attracted significant interest in recent years due to their exceptionally high theoretical energy density. If even 15% of this energy density is achieved, then it would equal the value of gasoline, making lithium-oxygen batteries with driving ranges of up to 500 miles per charge commercially viable. While this technology is very attractive, numerous technical challenges need to be overcome before its widespread adoption is possible. Some of these challenges include: (i) insolubility of the solid discharge reaction products, leading to clogging of the cathode and eventually resulting battery cell death; (ii) low roundtrip (discharge-charge cycle) efficiency due to high charge overpotentials to dissociate the main discharge reaction product, lithium peroxide; and (iii) instability of electrolytes at high overpotentials. This research project seeks to alleviate these issues by designing solid-solid interfaces at the cathode of lithium-oxygen batteries that selectively stabilize lithium-deficient discharge products that are not insulating and can be dissociated at reasonable overpotentials. The researchers will apply a combined experimental and theoretical approach to study the chemistry at these solid-solid interfaces with the aim of designing materials that can selectivity tune the discharge product distribution such that it leads to improved battery performance. In particular, the work will involve a combination of advanced characterization studies and theoretical calculations to determine how the elemental composition, electronic properties, and symmetry of the oxide surface influence the discharge product distribution in lithium-oxygen cathodes. The studies will elucidate the effect of the global oxide crystal structure on the discharge product formation and lead to the development of design principles for identifying oxide electrocatalysts that are highly selective towards the formation of lithium-deficient oxide discharge products and therefore exhibit low charge overpotentials.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.

锂氧电池可能具有可与汽油燃料相媲美的储能能力，但在该技术商业化之前，仍然需要了解许多有关这些电池的基础科学知识。特别是，电池运行过程中形成的一些化学产品会缓慢降解并使材料中毒，导致长时间运行后性能损失。该研究项目旨在通过探索一类可能改变锂氧电池化学性质的廉价混合金属氧化物电催化剂来克服这些问题。该项目旨在开发一个框架来设计锂氧电池的化学结构，并提高其性能，锂氧电池是一种潜在的下一代储能设备。这些研究结合了先进的表征方法和理论计算，以确定氧化物表面的特性如何影响锂氧电极上产生的产物。这些见解将用于开发设计原则，有助于识别可提高电池性能的氧化物电催化剂。参与该项目的研究人员将与当地 K-12 学校合作，通过暑期实习和学生交流，让经济困难的学生参与拟议的研究。 他们的目标是激励学生追求科学和工程领域的职业。对固-固界面发生的反应的基本了解对于开发下一代储能设备（例如锂氧电池）至关重要。 近年来，锂氧电池由于其极高的理论能量密度而引起了人们的极大兴趣。如果达到这个能量密度的 15%，那么它的价值就相当于汽油的价值，使得每次充电行驶里程高达 500 英里的锂氧电池在商业上可行。虽然这项技术非常有吸引力，但在广泛采用之前还需要克服许多技术挑战。其中一些挑战包括：（i）固体放电反应产物不溶，导致阴极堵塞并最终导致电池死亡； (ii) 由于高充电过电势导致主要放电反应产物过氧化锂解离，往返（放电-充电循环）效率低； (iii) 电解质在高过电势下的不稳定性。该研究项目旨在通过在锂氧电池的阴极设计固-固界面来缓解这些问题，该界面选择性地稳定不绝缘且可以在合理的过电势下解离的缺锂放电产物。研究人员将采用实验和理论相结合的方法来研究这些固-固界面的化学反应，目的是设计能够选择性调整放电产物分布的材料，从而提高电池性能。特别是，这项工作将涉及先进的表征研究和理论计算的结合，以确定氧化物表面的元素组成、电子特性和对称性如何影响锂氧阴极中的放电产物分布。 这些研究将阐明整体氧化物晶体结构对放电产物形成的影响，并导致开发用于识别氧化物电催化剂的设计原理，这些氧化物电催化剂对缺锂氧化物放电产物的形成具有高度选择性，因此表现出低充电过电势。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。