Investigation of Electrochemical Processes in Solid State Batteries

本研究的目的是利用计算和实验技术来了解以碱金属为阳极的固态电池（SSB）的复杂运行过程，并探索新的多组分固体电解质（MSE）配置以提高SSB的电化学性能。重点是固态电池，因为这些电池的进步将导致电动汽车的安全性，充电时间，行驶里程和寿命的急剧变化。1)利用量子力学（QM）和分子动力学（MD）方法研究新型mse：研究由无机固体电解质、聚合物、共聚物和填料组成的新型mse，结合各组分的优势，优化和改善其电化学特性。QM和MD模拟将用于设计和优化这些成分的组成，以实现具有高离子转移数，高电化学稳定性和更好的热稳定性等优越性能的mse。2)微纳米尺度工艺及失效机制的研究：MD模拟将用于了解枝晶的形成和扩展，限制临界电流密度的因素，ssb的失效机制，并制定提高临界剥离电流的策略。3)建立定量宏观电化学模型：为了了解新型MSEs在SSB中的性能，并解释材料性能与失效机制之间的关系，我们将建立一个非等温多物理场宏观模型来模拟SSB的充放电循环。QM和MD模型的计算将在宏观尺度模型中使用，以解释低尺度过程对电池整体性能的影响。4) mse的实验表征和计算模型的验证：在四种不同的c率和热力学条件下，进行电池循环实验，研究具有不同mse的ssb的电流-电压分布，并确定其耐久性、容量和效率。核磁共振波谱和显微技术将用于阐明降解机制。实验数据将用于确定模型的关键输入参数，并验证这些模型的预测。总之，拟议的研究计划将使用各种现代实验和建模技术来获得对SSB过程的基本理解，并帮助发展这项技术，为加拿大的可持续能源目标做出贡献。

The objective of this research is to use computational and experimental techniques to understand the complex processes that govern the operation of a Solid-State Battery (SSB) with an alkali metal as anode, and explore new and novel multi-component solid electrolyte (MSE) configurations to enhance the electrochemical performance of SSBs. The focus is on SSBs because advances in these batteries will result in steep changes in the safety, charging time, driving range, and longevity of electric vehicles. Investigations in this research will be aimed at the following: 1) Quantum mechanics (QM) and Molecular dynamics (MD) approach to study new MSEs: New and novel MSEs that are a combination of inorganic solid electrolytes, polymers, co-polymers, and fillers will be studied to optimize and improve their electrochemical characteristics, combining the advantages of each component. QM and MD simulations will be used to design and optimize the composition of these constituents to achieve MSEs with superior properties such as high ion transference number, high electrochemical stability, and better thermal stability. 2) Investigation of micro and nanoscale processes and the failure mechanisms: MD simulations will be used to understand the formation and propagation of dendrites, factors limiting the critical current densities, the failure mechanisms in SSBs, and develop strategies to improve the critical stripping current. 3) Develop a quantitative macroscale electrochemical model: To understand the performance of the new MSEs in SSBs and explain the relationship between material properties and failure mechanisms, we will develop a non-isothermal and multiphysics macroscale model to simulate the charge-discharge cycles of a SSB. Calculations from QM and MD model will be used within the macroscale model to account for the impact of the processes at lower scales on the overall performance of the battery. 4) Experimental characterization of MSEs and validation of the computational models: Battery cycling experiments will be performed to study the current-voltage profiles, and determine the durability, capacity, and efficiency of the SSBs with the different MSEs, under four distinct C-rates and thermodynamic conditions. NMR spectroscopy and microscopic techniques will be employed to elucidate the degradation mechanisms. The experimental data will be used to determine the key input parameters for the models and validate the predictions from these models. In summary, the proposed research program will use a variety of modern experimental and modelling techniques to gain a fundamental understanding of the processes in a SSB, and help evolve this technology, contributing to Canada's goals on sustainable energy.