Rational Design of Oxide Cathode Coatings for High Performance Li-ion Batteries

锂离子电池(LiB)广泛应用于便携式电子产品和电动汽车的储能设备中。提高这些电池的能量密度是必要的，以延长手机的运行时间和增加电动汽车的续航里程。提高锂离子电池能量密度的关键是能够对当前的锂离子电池阴极进行高压充电。由于阴极和电解液之间的寄生反应导致充放电循环中容量迅速衰减，这一努力受到了阻碍，这也损害了电池的安全性。解决这一问题的一个有效策略是在阴极表面涂上一种化学惰性材料作为屏障，以防止寄生反应的发生。该项目的目标是了解表面涂层的功能，以实现高能量密度LIBS的高压阴极。这项研究将解决LIBS发展过程中的一个主要挑战。为了扩大对STEM的参与，将实施艺术-科学伙伴关系，将科学进步与现实世界的应用联系起来。这将在宾厄姆顿大学现有的一年级研究沉浸和NSF本科生研究体验项目中实施。这项研究还将为学生提供劳动力培训机会，以熟练掌握制造级别的电池组装。商业化的锂离子电池技术依赖于富镍的层状氧化物阴极，以实现当今应用(电动汽车、电网存储等)所需的高能量密度和功率输出。涂层已被广泛用作工程解决方案，以提高这些氧化物阴极的性能和可靠性，但它们在循环过程中的潜在功能仍不清楚。本项目研究氧化铝涂层(氧化铝和LiAlO2)及其对锂离子传输、阴极-电解液界面稳定性和循环性能的影响，这两个系统是：高质量的LiCoO2薄膜和商业LiNi0.8Mn0.1Co0.1O2(NMC 811)微米级颗粒。原子和化学X射线光谱和衍射表征将与从头算分子动力学模拟相联系，以直接确定使用铝涂层可以在多大程度上避免有害的降解途径，如颗粒破裂、氧损失和过渡金属还原。这项研究将提供对原子级工艺的洞察，以指导可扩大到制造级测试的坚固涂层的开发。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。

Li-ion batteries (LIBs) are ubiquitous, used as energy storage devices in portable electronics and electrical vehicles. Increasing the energy density of these batteries is necessary to allow for longer runtime of cell phones and the increased range of electrical vehicles. Critical to increasing the energy density of LIBs is enabling high-voltage charging of current LIB cathodes. This effort is hindered by the rapid capacity fading over charge-discharge cycles caused by parasitic reactions between the cathode and the electrolyte that also undermine the battery’s safety. One effective strategy to overcome this problem is to coat the cathode surface with a chemically inert material as a barrier to prevent the parasitic reactions from occurring. The goal of this project is to understand the functionality of the surface coating to enable high-voltage cathodes for high energy density LIBs. This research will address a major challenge in the advancement of LIBs. To broaden the participation in STEM, an art-science partnership will be implemented to connect scientific advances to real-world applications. This will be implemented in the existing First-year Research Immersion and the NSF Research Experience for Undergraduates programs at Binghamton University. This research will also offer workforce training opportunities for students to gain proficiency in manufacturing-level battery assembly. Commercialized Li-ion battery technologies are reliant on Ni-rich layered oxide cathodes to achieve the high energy density and power output required for today’s applications (electric vehicles, grid storage, etc.). Coating layers have been widely employed as engineering solutions to improve the performance and reliability of these oxide cathodes, yet their underlying functionality during cycling remains unclear. This project addresses aluminum oxide coatings (Al2O3 and LiAlO2) and their impact on Li-ion transport, cathode-electrolyte interface stability, and cycling performance for two systems: high quality LiCoO2 thin films and commercial LiNi0.8Mn0.1Co0.1O2 (NMC 811) micron-sized particles. Atomic and chemical X-ray spectroscopic and diffraction characterization will be connected to ab initio molecular dynamics simulations to directly identify the extent to which detrimental degradation pathways, e.g. particle cracking, oxygen loss, and transition metal reduction, are avoided with the use of aluminum coatings. The research will provide insight into atomic level processes in order to guide the development of robust coating layers that can be scaled up into manufacturing-grade testing.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.