Computation Accelerated Design of Materials and Interfaces for Solid-State Batteries

18 Apr
Applied Mechanics Colloquia
Yifei Mo
Wednesday, April 18, 2018 -
4:00pm to 5:00pm
Pierce 209

All-solid-state Li-ion battery based on solid electrolytes is a promising next-generation battery technology with high energy density, intrinsic safety, long-life cyclability, and high-rate charging/discharging. However, multiple challenges, such as the lack of super-ionic solid electrolytes and poor interfacial compatibility at the solid electrolyte-electrode interfaces, are impeding the development of this novel technology. To resolve these materials challenges, we will design new materials and interfaces through an accelerated approach guided by first principles computation, in contrast to a conventional trial-and-error approach. We will leverage an array of computation techniques to provide unique materials insights into the fundamental materials limitations and to establish general design principles of materials for overcoming such challenges. In the first part of the presentation, we will use first-principles atomistic modeling to reveal the origin of ultra-fast diffusion in lithium super-ionic conductors, which uniquely exhibit several orders of magnitude higher ionic conductivity than most solids. Materials design principles for fast ion conductors will be established based on the newly gained understanding, and such design principles will be demonstrated in our computation-guided discovery and design of new super-ionic conductors. In addition, we will present our first-principles database approach in investigating the compatibility of heterogeneous interfaces between electrolyte and electrodes, which are difficult to access in experiments. Key limiting factors at the solid electrolyte-electrode interfaces will be identified, and corresponding interfacial design using new materials will be proposed from computation guidance to address these interfacial limitations. The demonstrated computation capabilities represent a transferable workflow in designing new materials for emerging technologies. 

Xin Li