CAREER: Enabling High-performance Na-ion Battery Cathodes Via Structural Pillaring

向可再生能源的过渡需要大规模的能源存储解决方案，以应对太阳能和风能等可再生能源的间歇性发电。虽然锂离子电池广泛用于便携式设备和电动汽车的储能，但锂资源的高成本对其在大规模应用（如电网储能）中的应用构成了障碍。由于钠的普遍存在，钠离子电池有望取代锂离子电池进行大规模部署。然而，目前的钠离子电池受到几个有害过程的困扰，这些过程损害了它们的性能并破坏了它们在电网储能中的部署。为了实现高性能的钠离子电池，必须制定克服这些缺点的策略。该研究项目将研究结构支柱作为解决钠离子电池电极挑战的有效策略。该研究项目将为美国的清洁能源劳动力培养本科生和研究生。教育和推广计划将采用互动式教学法，向各级受众讲授和推广电化学储能科学。这将涉及到教育游戏的开发，将其作为一个平台，吸引各个层次的学习者。这些教育工具包将被整合到电化学储能课程开发和针对K-12学生和教师的各种推广项目中。该研究的目标是阐明离子-离子和离子-晶格相互作用的基本材料描述符，这些描述符不仅支持na离子插入，还支持其他非锂离子，如K离子和ca离子，化学的层状过渡金属氧化物电极的一系列有害相变。本研究的基本贡献是确定了层状过渡金属氧化物相互作用的材料描述符，这将允许合理设计层状过渡金属氧化物的性质和插层化学。以na基层状过渡金属氧化物为模型化合物，研究通过改变插层离子的组成和性质来实现离子-离子和离子-晶格相互作用的变化，如何影响层状氧化物的层-滑动相变、na离子/空位有序、na离子扩散以及化学和电化学稳定性。这些性质和过程将由一套互补的电化学、结构和热分析技术来表征。本研究结果将为克服高压下可逆钠离子嵌入的障碍提供合理的解决方案。实际意义是开发“设计材料”，抑制/减轻插层反应中的有害相变和过程，从而实现高性能储能材料。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。

The transition to renewable energy sources calls for large-scale energy storage solutions to cope with the intermittent energy generation by renewables, such as solar and wind. While lithium (Li)-ion batteries are widely used in portable devices and electric vehicles for energy storage, the high cost of lithium resources poses barriers to their adoption in large-scale applications, such as electric grid energy storage. Sodium (Na)-ion batteries are promising alternatives to Li-ion batteries for large-scale deployment because of the ubiquity of sodium. However, current Na-ion batteries are plagued by several deleterious processes, which compromise their performance and undermine their deployment for grid energy storage. Strategies to overcome these shortcomings must be developed to realize high-performance Na-ion batteries. The research project will investigate structural pillaring as an effective strategy to address the challenges of Na-ion battery electrodes. The research program will train both undergraduate and graduate students for the clean energy workforce in the United States. The educational and outreach programs will implement an interactive pedagogy in teaching and promoting the science of electrochemical energy storage to an audience at all levels. This will involve the development of educational games as a platform to engage learners at all levels. These educational kits will be integrated into the curriculum development on electrochemical energy storage and various outreach programs targeting both K-12 students and teachers.The goal of the research is to elucidate the fundamental material descriptors for the ion-ion and ion-lattice interactions, which underpin a range of deleterious phase transitions of layered transition metal oxide electrodes for not only the Na-ion intercalation but also other beyond-Li-ion, such as K- and Ca-ion, chemistries. The fundamental contribution of this research is the identification of the material descriptors for the interactions of the layered metal oxide, which will allow for the rational design of the property and the intercalation chemistry of the layered transition metal oxides. Adopting the Na-based layered transition metal oxide as the model compound, the research will elucidate how changes in the ion-ion and the ion-lattice interactions, which is realized by varying the composition and nature of the intercalant ions, affect the layer-gliding phase transition, Na-ion/vacancy ordering, Na-ion diffusion, and the chemical and electrochemical stability of the layered oxides. These properties and processes will be characterized by a suite of complementary electrochemical, structural, and thermal analytical techniques. The outcome of this research will lead to a rational solution to overcome the barriers for the reversible Na-ion intercalation at high voltages. The practical implication is the development of “designer materials” that suppress/mitigate the deleterious phase transitions and processes in the intercalation reaction, thereby enabling high-performance energy storage 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.