Interface chemistry and electrochemistry in magnesium-ion batteries

大规模、固定的应用需要改进的储能技术，例如电网负载均衡和间歇性可再生能源发电的储能。镁电池是锂离子电池最引人注目的替代品之一，在安全性、资源丰富以及二价镁离子可能带来的更高容量方面具有显著优势。与技术成熟的锂离子电池相比，镁电池的开发要少得多。随着锂离子电池能量密度达到极限，人们对这项技术的兴趣也在增加。在这个研究项目中，研究人员将解决镁电池面临的关键科学挑战，并为新的能量存储技术铺平道路。该基础研究项目将在可持续清洁能源材料和制造技术领域为研究生和本科生提供教育和研究经验。该项目还将在研究生和本科生中培养一种积极的文化，接受、尊重和容忍他人的差异。本研究项目研究的是阳极-电解液和阴极-电解液界面，而不是分别研究这三个组分。其战略是将这三个组件结合在一起，作为一个系统来提供关于接口的更多见解，以解决镁电池的两个最大问题：阳极钝化和高能阴极的缺乏。项目组已经展示了一种氟化物涂层，它作为第一个传导镁离子的固体-电解质界面层，将对该层进行更详细的表征，以了解和改进其电化学性能。该项目将包括设计电化学协议，以测量真正的阴极性能，并使不同实验室的阴极测试标准化。分析和表征模板允许快速电化学筛选预期材料，并利用X射线衍射仪和新的原位EXAFS技术进行表征。最有希望的镁正极材料将受到研究人员先前为锂离子电池材料开发的缺陷工程策略的影响。其中一些工具包括阳离子或阴离子掺杂、通过受控退火引入空位、使用离子交换修改表面化学以及合成非晶态材料。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Improved energy storage technologies are required for large-scale, stationary applications such as grid load leveling and energy storage for intermittent renewable electricity generation. Magnesium batteries are among the most compelling alternatives to lithium-ion batteries, with significant advantages in terms of safety, resource abundance, and possible higher capacities by virtue of the divalent magnesium ion. Magnesium batteries are far less explored than the technologically mature lithium-ion battery. Interest in this technology has increased as limits in lithium ion battery energy density are reached. In this research project, researchers will address key scientific challenges facing magnesium batteries and pave the way for new energy storage technologies. This fundamental research project will educate and provide research experiences to graduate and undergraduate students in the field of sustainable clean energy materials and manufacturing technology. The project will also foster a positive culture among graduate and undergraduate students that accepts, respects and tolerates differences of others. This research project investigates the anode-electrolyte and cathode-electrolyte interfaces, rather than the three components individually. The strategy is to view the combined three components as a system to provide additional insights about the interfaces to address two of the biggest problems for magnesium batteries: passivation of the anode and the dearth of high-energy cathodes. The project team has demonstrated a fluoride coating that functions as the first solid-electrolyte interphase layer to conduct magnesium ions, and the layer will be characterized in greater detail to understand and improve upon its electrochemical performance. The project will include the design of electrochemical protocols to measure the true cathode performance and standardize cathode testing across different laboratories. The analysis and characterization templates allow for rapid electrochemical screening of prospective materials and characterization with XRD and new in situ EXAFS techniques. The most promising magnesium cathode materials will be subjected to defect engineering strategies previously developed by the researchers for lithium-ion battery materials. Some of these tools include cation or anion doping, introducing vacancies through controlled annealing, modification of surface chemistry with ion exchange, and synthesizing amorphous materials.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.