CDMR: Design and Processing of High-Energy-Density Cathodes for Li-ion Batteries

技术摘要最近，一类新的高能量密度，锂和锰丰富的层状阴极材料已被发现。该项目旨在通过集成的第一性原理计算、CALPHAD建模、材料加工以及电池组装和测试，建立设计和加工具有所需特性的材料所需的基本知识库。这一基础知识库也为发现新的阴极材料奠定了基因组基础。这种新的正极材料存在于xLi 2 MnO 3？（1-x）LiMO 2的多组分空间中，其中M是包括Mn、Co和Ni的合金元素。在该项目中，第一性原理计算将用于系统地研究这些常见合金元素和潜在异常值对电子结构和电荷转移的影响，并预测各个相的热力学性质作为温度和成分的函数。将利用CALPHAD建模来建立相关系并优化组成空间（x和M），以获得上级充放电性能。为了验证第一原理计算和CALPHAD建模的预测，阴极材料将以定制的成分合成，并组装纽扣电池以测试电池性能。该项目的目标是：1.对合金元素的影响建立基本的认识并寻找潜在的异常值：2.对Li-Mn-Co-Ni-O系统及其潜在的异常值进行热力学描述; 3.基于计算建模和反馈来合成和表征阴极材料并测试电池性能以改进数据库。非技术性概述新材料的开发以及定制现有材料以满足新需求的能力应用对于人类生活质量的持续改善至关重要。材料是美国制造业全球竞争力的决定性因素，因为材料占大多数制造产品成本的一半。锂离子可充电电池是电子设备和电动汽车等众多应用所需的低成本和高能量密度存储的关键组成部分。由于当前可充电锂离子电池中使用的阴极的成本和能量密度的限制，新型阴极的开发是至关重要的。最近，已经发现了一类新的高能量密度、富含Li和Mn的层状阴极材料。该项目旨在通过集成的第一性原理计算、热力学建模、材料加工以及电池组装和测试，建立设计和加工具有所需性能的材料所需的基础知识库。这一基础知识库也为发现新的阴极材料奠定了基因组基础。该提案的智力价值在于其理论、计算和实验之间的协作、协同方法，以快速构建富锂和富锰层状阴极材料的化学-加工-结构-性质-性能知识库。这种综合方法将基于电池材料模拟、合成和评估方面的综合专业知识。该研究项目旨在将美国的低成本和高能量密度阴极材料研究提升到一个新的水平，进一步建立基础，以回答只有通过结合计算和实验方法才能有效解决的基本问题。这些问题包括：就成本和性能而言，Li/Mn/M层的最佳组合是什么？对于它们的稳健加工，成分/温度变化是什么？合金元素的潜在异常值是什么，以获得上级性能？更广泛的影响包括以下几个方面，除了低成本和高能量密度的正极材料对电池制造的经济影响外，a）教育学生成为掌握材料和电池跨学科知识的创新计算和实验方法的专业人员; B）鼓励学生在专业会议上进行演讲，以提高沟通技巧; c）通过同行评审的期刊出版物培养学生的写作技能; d）通过SEEMS参与扩大代表性不足群体参与的活动（地球和矿物科学夏季经验）高中生和WISER计划（妇女在科学和工程研究）方案为一年级学生，e）、有助于新材料研究范式，缩短开发新材料和改进现有材料的时间，以最大限度地减少社会成本和对环境的负面影响。提高美国制造业的竞争力。

Technical AbstractRecently, a new class of high-energy-density, Li- and Mn-rich layered cathode materials has been discovered. The project aims to build the fundamental knowledge base needed to progress towards design and processing of the materials with desired properties through integrated first-principles calculations, CALPHAD modeling, materials processing, and battery assembling and testing. This fundamental knowledge base also builds the genome foundation to discover new cathode materials. The new cathode material resides in a multi-component space of xLi2MnO3ª(1-x)LiMO2 with M being alloying elements including Mn, Co, and Ni. In the project, first-principles calculations will be used to systematically investigate the effects of these common alloying elements and potential outliers on electronic structures and charge transfers and predict thermodynamic properties of individual phases as a function of temperature and compositions. CALPHAD modeling will be utilized to establish phase relations and optimize the composition space (x and M) for superior charging-discharging performance. To validate the predictions from first-principles calculations and CALPHAD modeling, cathode materials will be synthesized with tailored composition and assemble coin cells to test battery performance. The project objectives are: 1.Establish fundamental understanding of effects of alloying elements and search for potential outliers;2.Develop a thermodynamic description of the Li-Mn-Co-Ni-O system plus potential outliers;3.Synthesize and characterize cathode materials and test battery performance based on computational modeling and feedback to improve databases.Nontechnical SummaryThe development of new materials and the capability of tailoring existing materials to meet new and demanding applications are critical for continued improvements in the quality of human life. Materials are a determining factor in the global competitiveness of the U.S. manufacturing industry as materials account for up to half of the costs of most manufactured products. Li-ion rechargeable batteries are the key constituent for low cost and high-energy-density storages needed for numerous applications such as electronic devices and electric vehicles. The development of novel cathodes is critical because of the limitations of cost and energy density for cathodes used in current rechargeable Li-ion batteries. Recently, a new class of high-energy-density, Li- and Mn-rich layered cathode materials has been discovered. The project aims to build the fundamental knowledge base needed to progress towards design and processing of the materials with desired properties through integrated first-principles calculations, thermodynamic modeling, materials processing, and battery assembling and testing. This fundamental knowledge base also builds the genome foundation to discover new cathode materials.The proposal's intellectual merit lies on its collaborative, synergistic approaches between theory, computation, and experiments to rapidly build a chemistry-processing-structure-property-performance knowledge base for the Li- and Mn-rich layered cathode materials. This integrated approach will be based on the combined expertise in simulations, syntheses, and evaluation of battery materials. The research project aims to move the low cost and high-energy-density cathode materials research in the US to a new level by further building the foundation to answer fundamental questions that can only be addressed efficiently via combined computational and experimental methodology. These include: what is the best combination of Li/Mn/M layers in terms of cost and performance? what are the composition/temperature variations for their robust processing? and what are the potential outliers of alloying elements for superior performances?Broader impacts include following aspects, in addition to economic impact of low-cost and high-energy-density cathode materials on battery manufacturing, a) educate students to be professionals mastering both innovative computational and experimental approaches with cross-disciplinary knowledge of materials and batteries; b) encourage students to make presentations at professional meetings to improve communication skills; c) foster students' writing skills through peer reviewed journal publications; d) participate in activities to broaden the participation of underrepresented groups through the SEEMS (Summer Experience in Earth and Mineral Science) programs for high school students and WISER (Women in Science and Engineering Research) program for first year students, e) contribute to new materials research paradigm in shortening the time for developing new materials and improving existing materials to minimize the cost to the society and the negative impact to the environment, and increasing the competitiveness of US manufacturing.