Ionic Conductivity in Doped Polymers Studied by Molecular Simulation

该项目旨在探索由聚合物、离子和掺杂剂组成的分子水平体系，以更好地掌握离子的本征电导率和形态。归根结底，我们应该能够提出，或者至少指导合成有前途的新系统。为了实现这一目标，我们受益于这样一个事实，即我们可以访问道达尔通过与蒙特雷亚尔大学和多伦多大学的团队合作获得的大量实验数据。此外，我们还汇集了仿真领域的不同专业知识。在这个为期两年的项目中，我们逐步开发了使我们的目标可行的模拟工具。验证步骤是模拟过程中的一个强制性阶段，包括准确地准备模型系统：PEO/LiTFSI。然后考虑了与两个提议的工作计划(WP)相对应的两条发展路径：1)计算电导率和2)揭示形态。这两种可湿性粉剂都显示出共同的特点：制备体系，实施协议以获得感兴趣的性质，生成包含不同离子或不同浓度的掺杂剂的新体系，以及使用PEO以外的聚合物。这样的发展轴是大多数模拟技术所共有的。然而，这两个提议的WP在它们处理的细节水平上是不同的：WP1和WP2的原子水平和介观水平。这两种战略必须导致相同的结果：提出建议，或者至少是开发更有效的新系统的指南。为此，我们项目的发展历时两年，有4项成果，涉及1名博士生和2名博士后研究员。

The project is aimed at probing a molecular level system constituted of a polymer, ions and dopants, to better grasp the intrinsic ionic conductivity and morphology. Ultimately, we should be able to propose, or at least to guide the synthesis of promising new systems. To reach this goal, we benefit from the fact that we have access to a great number of experimental data acquired by TOTAL through collaborations with teams from Université de Montréal and University of Toronto. Moreover, we bring together different expertise in the simulation domain. During this 2-year project, we thus progressively develop the simulation tools that make our goal doable. The validation step, a mandatory stage during simulation, consists in accurately preparing the model system: PEO / LiTFSI. Two development paths that correspond to the two proposed work plans (WP), are then considered: 1) computing conductivities and 2) unveiling the morphology. Both WP show common features: preparation of the systems, implementation of protocols to get properties of interest, generation of new systems containing different ions or dopants at different concentrations, and with polymers other than PEO. Such axis of development is common to most of the simulation techniques. However, the two proposed WPs differ on the level of details they handle: atomistic and mesoscopic levels for WP1 and WP2, respectively. Both strategies must lead to the same outcome: proposal, or at least a guide to develop, new and more efficient systems. For this, the development of our project takes place over a period of two years, marked by 4 deliverables, involving 1 Ph.D. student, and 2 postdoctoral fellows.