Lattice dynamics in ionic conductors

具有大离子电导率的固体离子导体在电池、固体氧化物燃料电池、太阳能热发生器和氧传感器等许多应用中具有不可替代的作用。更好地从根本上了解固态中的离子传输预计将影响这些相关领域，并有助于下一代能源技术。在静态晶格环境下，研究固态离子传导的经典方法主要集中在晶体扩散路径和载流子浓度的优化上。化学直觉有助于利用具有更强极化和更柔软晶格的固体来识别更好的离子导体，这表明动态晶格对离子输运的影响更大。这一假设是基于晶格和移动离子之间的相互作用，即晶格动力学的变化将影响离子的运动。晶格极化率、晶格柔软度和晶格振动的非谐性的影响将被研究、测量并与离子电导的变化相关联。这一建议寻求通过将有经验的申请人在热电领域获得的知识和工具集与离子导体相结合来更好地从根本上了解固体中的离子传导性。

Solid ion conductors with large ionic conductivities are irreplaceable in many applications such as batteries, solid oxide fuel cells, solar thermal generators, and oxygen sensors. A better fundamental understanding of ionic transport in the solid-state is expected to impact these related fields and help with next-generation energy technologies. Classical approaches for understanding ionic conduction in the solid state focus on crystallographic diffusion pathways and optimization of carrier concentration assuming a static lattice environment. Chemical intuition has helped to identify better ionic conductors using solids with more polarizable and softer lattices, suggesting a greater influence of a dynamic lattice on the ionic transport.The hypothesis of this proposal is based on the interactions between the lattice and the moving ion; that is, changes in the lattice dynamics will influence ionic motion. The effect of lattice polarizability, lattice softness and anharmonicity of lattice vibrations will be studied, measured and correlated to changes in the ionic conduction. This proposal seeks a better fundamental understanding of ionic conductivity in solids by combining the knowledge and toolset of the experienced applicant, gained in the field of thermoelectrics, with ionic conductors.