School of Mechanical Engineering, Purdue University , West Lafayette, Indiana 47907, United States.
National Renewable Energy Laboratory , Golden, Colorado 80401, United States.
ACS Appl Mater Interfaces. 2018 Feb 21;10(7):6317-6326. doi: 10.1021/acsami.7b17771. Epub 2018 Jan 23.
Lithium-ion battery electrodes exhibit complex interplay among multiple electrochemically coupled transport processes, which rely on the underlying functionality and relative arrangement of different constituent phases. The electrochemically inactive solid phases (e.g., conductive additive and binder, referred to as the secondary phase), while beneficial for improved electronic conductivity and mechanical integrity, may partially block the electrochemically active sites and introduce additional transport resistances in the pore (electrolyte) phase. In this work, the role of mesoscale interactions and inherent stochasticity in porous electrodes is elucidated in the context of short-range (interface) and long-range (transport) characteristics. The electrode microstructure significantly affects kinetically and transport-limiting scenarios and thereby the cell performance. The secondary-phase morphology is also found to strongly influence the microstructure-transport-kinetics interactions. Apropos, strategies have been proposed for performance improvement via electrode microstructural modifications.
锂离子电池电极表现出多种电化学耦合传输过程之间的复杂相互作用，这依赖于不同组成相的基础功能和相对排列。电化学惰性的固相（例如导电添加剂和粘结剂，称为二次相）虽然有利于提高电子导电性和机械完整性，但可能部分阻塞电化学活性位点，并在孔（电解质）相中引入额外的传输阻力。在这项工作中，阐明了介观相互作用和多孔电极固有随机性在短程（界面）和长程（传输）特性方面的作用。电极微结构显著影响动力学和传输受限的情况，从而影响电池性能。还发现二次相形态强烈影响微观结构-传输-动力学相互作用。因此，提出了通过电极微结构改性来提高性能的策略。
