Collaborative Research: Dynamics of chalcogenide-doped high capacity lithium-ion battery anode materials during cycling using in situ imaging

合作研究：利用原位成像研究硫属化物掺杂高容量锂离子电池负极材料在循环过程中的动力学

• 批准号: 1604104
• 负责人: Lei Chen
• 金额: $ 5万
• 依托单位: Mississippi State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-08-01 至 2020-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1604104&HistoricalAwards=false
• 关键词: Collaborative; Research; Dynamics; chalcogenide; doped

Rechargeable lithium ion batteries help to enable sustainable energy systems by storing electricity generated by intermittent renewable resources such as wind and solar energy, or by powering zero-emission electric vehicles charged by electricity from renewable resources. The two key performance measures of lithium ion batteries are capacity and recharge rate, which determine how much energy a battery can store and how long it takes to fully recharge. One approach to significantly improve capacity is to replace conventional graphite anodes with alloy-type anode materials that include the elements silicon (Si), germanium (Ge), and tin (Sn). However, these alloy materials swell up after charging, which promotes mechanical failure. This project will address this issue by adding the element selenium (Se) to alloy-type anodes made from micrometer sized particles. The resulting Se-doped microparticles may be able to reduce swelling of the anode. Advanced imaging and computational studies will gain a fundamental scientific understanding of these processes, with the long-term goal of developing commercially affordable, high-performance anode materials for better batteries. The research will be a collaborative effort between researchers at three universities - Indiana University, Mississippi State University, and the University of Texas at Austin. Furthermore, the educational activities associated with this project will be coordinated between these three institutions, and will include integration of the research into undergraduate and graduate course lectures, involvement of undergraduate students and K-12 teachers in research, and outreach to pre-college students through development of short, energy-related animated videos.The overall goal of the research is to develop a fundamental understanding of the electrochemical, material phase, and morphological dynamics of Se-doped Ge and Sn microparticles during lithiation and de-lithiation reactions with lithium ion battery alloy-type anodes. The research plan has two objectives. The first objective is to investigate the dynamics of Se-doped materials during lithiation and de-lithiation, focusing on in situ measurement of phase and morphology change via in situ X-ray powder diffraction (XRD), transmission electron microscopy (TEM) and transmission X-ray microscopy (TXM). Concurrently, the composition of the Se-containing inactive phase will be identified and its ionic conductivity will be determined. Furthermore, the effect of the active/inactive mixed phases on cycling performance for both Ge- and Sn-based electrodes will be studied. The second objective is to develop correlations between lithium ion battery cell performance and changes in Se-Ge and Se-Sn electrode microstructure through the afore-mentioned experiments and theoretical modeling. A phase field model that integrates the processes of electrochemical reaction, species diffusion, interfacial effects, as well as large elastoplastic deformation will be developed to simulate the concurrent evolution of phases, morphologies and stress within a Ge-Se or Sn-Se particle during lithiation and de-lithiation. Since it is likely that future high-capacity electrode materials will have large volume changes, the outcomes from the research may enable development of these new battery systems.

可充电锂离子电池通过存储由间歇性可再生资源（例如风能和太阳能）产生的电力，或通过为可再生资源电力收取的零发射电动汽车而产生的电力来实现可持续的能源系统。 锂离子电池的两个关键性能度量是容量和充电速率，这决定了电池可以存储多少能量以及完全充电所需的时间。一种显着提高能力的一种方法是用合金型阳极材料替换常规的石墨阳极，其中包括元件硅（SI），锗（GE）和锡（SN）。 但是，这些合金材料在充电后膨胀，从而促进机械故障。该项目将通过将元素硒（SE）添加到由微米大小的颗粒制成的合金型阳极中来解决此问题。 所得的SE掺杂微粒可能能够减少阳极的肿胀。 先进的成像和计算研究将获得对这些过程的基本科学理解，其长期目标是开发商业上负担得起的高性能阳极材料，以提供更好的电池。这项研究将是三所大学的研究人员 - 印第安纳大学，密西西比州立大学和德克萨斯大学奥斯汀分校之间的合作努力。 此外，与该项目相关的教育活动将在这三个机构之间进行协调，并将包括将研究整合到本科生和研究生课程讲座中在与锂离子电池合金型阳极的静脉和去置化反应过程中，Se掺杂的GE和SN微粒的动力学。 研究计划有两个目标。第一个目的是研究岩石和去斜率期间SE掺杂材料的动力学，重点是原位测量相位和形态的变化，通过原位X射线粉末衍射（XRD），透射电子显微镜（TEM）和透射X射线显微镜（TXM）。 同时，将确定含Se的非活性相的组成，并确定其离子电导率。此外，将研究活性/非活性混合阶段对GE-和SN基电极循环性能的影响。 第二个目标是通过上述实验和理论建模之间发展锂离子电池性能与SE-GE和SE-SN电极微结构的变化之间的相关性。 将开发一个相结合电化学反应，物种扩散，界面效应以及大型弹性变形的过程的相位场模型，以模拟在岩性和去岩性期间的GE-SE或SN-SE粒子中的相位，形态和压力的同时演变。 由于未来的高容量电极材料可能会发生较大的体积变化，因此研究的结果可能使这些新电池系统能够开发。