Explore Electrocatalysis to Improve the Cathode Performance in Li-S Batteries

探索电催化提高锂硫电池正极性能

• 批准号: 2054754
• 负责人: Jun Li
• 金额: $ 38.64万
• 依托单位: Kansas State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-07-15 至 2025-06-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2054754&HistoricalAwards=false
• 关键词: Explore; Electrocatalysis; Improve; Cathode; Performance

Lithium-ion batteries are leading technologies for electric vehicles and large-scale renewable energy storage. Lithium-sulfur battery technology, in particular, is a forerunner of next-generation lithium-ion batteries due to their material availability and their high energy density. The project will investigate a new electrocatalytic concept for improving the performance of lithium sulfide batteries. Specifically, the goal is to enhance charge/discharge rates and suppress battery deactivation, both of which are limiting the performance of current Li-S batteries. Beyond the technical aspects, the project includes educational and outreach activities, focusing on underrepresented students from middle- and high-school to graduate level. Advances in LiS battery technology are hindered by several critical barriers, including the low electrical conductivity of elemental S and discharged product Li2S at the cathode, high overpotentials, and the rapid capacity fading of the S cathode due to diffusion of soluble lithium polysulfide (LiPS) intermediates from the cathode to react with the Li anode, notoriously known as the “shuttle effect”. Transition metal sulfide electrocatalysts with strong adsorption of LiPS intermediates will be explored to accelerate the conversion between S and Li2S, the two insoluble end products. The project focuses on improving the cathode performance based on the new electrocatalytic concept using two types of hybrid materials as the electrocatalysts, i.e. the two-dimensional (2D) atomic layered MoS2 and the quasi-1D chain-like VS4, both strongly attached on highly conductive reduced graphene oxide (rGO) nanosheets. The specific objectives include (1) catalyst synthesis and characterization (including their ability for LiPS adsorption and electrocatalytic conversion); (2) electrocatalytic LiPS trapping and conversion (via hybrid materials incorporation in the interlayer and the S/C cathode, respectively), and (3) electrocatalytic conversion of Li2S to S. The MoS2/rGO and VS4/rGO catalysts will be incorporated in the lithium-loaded Li2S/C cathode to reduce the activation energy of the initial delithiation of Li2S and enable a stable and reversible Li2S/C cathode. Electrochemical characterizations will be correlated with both ex-situ and operando micro-Raman spectroscopy studies to provide a good understanding of the dynamic charge/discharge processes and render mechanistic insights of the electrocatalysis. These studies will provide solutions to realize the full potentials of the Li-S batteries, an important sustainable energy technology. In addition to the technical objectives, this project provides cross-disciplinary training in nanomaterials synthesis/characterization, electrochemistry, catalysis and energy storage technologies to two graduate students and one undergraduate student. The project team will participate in summer STEM camps to engage with high/middle school students (particularly girls in Kansas) and provide hands-on workshops using the materials developed in this project. An outreach effort will be made through a strong collaboration with Xavier University of Louisiana (XULA), a Historically Black Colleges and Universities (HBCU), to host visiting undergraduate students from XULA for summer research on electrical energy storage in Kansas State University.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.

锂离子电池是电动汽车和大规模可再生能源存储的领先技术。特别是锂硫电池技术，由于其材料可用性和高能量密度，是下一代锂离子电池的先驱。 该项目将研究一种新的电催化概念，以提高硫化锂电池的性能。 具体而言，目标是提高充电/放电速率并抑制电池失活，这两者都限制了当前Li-S电池的性能。除了技术方面，该项目还包括教育和外联活动，重点是从初中和高中到研究生阶段代表性不足的学生。 LiS电池技术的进步受到几个关键障碍的阻碍，包括阴极处元素S和放电产物Li 2S的低电导率、高过电位以及由于可溶性多硫化锂（LiPS）中间体从阴极扩散以与Li阳极反应而导致的S阴极的快速容量衰减，众所周知的是“穿梭效应”。 将探索具有强吸附LiPS中间体的过渡金属硫化物电催化剂，以加速S和Li 2S这两种不溶性最终产物之间的转化。 该项目的重点是基于新的电催化概念，使用两种类型的混合材料作为电催化剂，即二维（2D）原子层状MoS 2和准一维链状VS 4，两者都牢固地附着在高导电性的还原氧化石墨烯（rGO）纳米片上。具体目标包括（1）催化剂合成和表征（包括其LiPS吸附和电催化转化的能力）;（2）电催化LiPS捕集和转化（分别通过在夹层和S/C阴极中掺入混合材料），和（3）Li 2S到S的电催化转化。 MoS 2/rGO和VS 4/rGO催化剂将被纳入负载锂的Li 2S/C阴极中，以降低Li 2S初始脱锂的活化能，并实现稳定且可逆的Li 2S/C阴极。电化学表征将与非原位和操作显微拉曼光谱研究，以提供一个很好的理解的动态充电/放电过程，并呈现电催化机理的见解。 这些研究将为实现锂硫电池的全部潜力提供解决方案，这是一项重要的可持续能源技术。除了技术目标外，该项目还为两名研究生和一名本科生提供纳米材料合成/表征，电化学，催化和储能技术的跨学科培训。项目团队将参加STEM夏令营，与高中生（特别是堪萨斯的女孩）接触，并使用本项目开发的材料提供实践研讨会。将通过与路易斯安那州泽维尔大学（Xavier University of Louisiana）、一所历史上的黑人学院和大学（HBCU）的密切合作，接待来自Xampton的访问本科生，在堪萨斯州立大学进行关于电能存储的夏季研究。该奖项反映了NSF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进行评估，被认为值得支持的搜索.

项目成果

Binder-free Li-O 2 battery cathodes using Ni- and PtRu-coated vertically aligned carbon nanofibers as electrocatalysts for enhanced stability

使用 Ni 和 PtRu 涂层垂直排列碳纳米纤维作为电催化剂以增强稳定性的无粘合剂 Li-O 2 电池阴极

• DOI: 10.26599/nre.2023.9120055
• 发表时间: 2023
• 期刊: Nano Research Energy
• 作者: Hassan Zaidi, Syed Shoaib;Rajendran, Sabari;Sekar, Archana;Elangovan, Ayyappan;Li, Jun;Li, Xianglin
• 通讯作者: Li, Xianglin

Mechanistic understanding of Li metal anode processes in a model 3D conductive host based on vertically aligned carbon nanofibers

• DOI: 10.1016/j.carbon.2023.118174
• 发表时间: 2023-05-31
• 期刊: CARBON
• 影响因子: 10.9
• 作者: Rajendran，Sabari;Sekar，Archana;Li，Jun
• 通讯作者: Li，Jun