MATERIALS SCIENCE AND ENGINEERING

SEMINAR

Minimal Tortuosity Rechargeable Batteries: a Critical Analysis

By:

Yunbo Wang

Ph.D. Prelim Exam – Part I

Advisor:

Prof. R. E. Garcia

ABSTRACT

In this prelim 1, existing and emerging microstructural science aspects that aim to describe the transport properties of the random porous structure of currently used commercial rechargeable lithium-ion batteries are reviewed. Most of the existing work is based on the Bruggeman relationship, which underestimates the transport resistance in porous electrodes due to the particle shape anisotropy and randomness in orientation. A two-dimensional OOF model was developed to quantify the transport for various electrode morphologies. Two possible electrode microstructure-optimizing approaches are presented to lower the lithium-ion transport resistance: a) Preparation of perfectly spherical LiMn2O4 particles through an emulsion-gel method. Here, a manganese acetate-based precursor will be heat-treated and further cast into 13mm diameter disk-shaped electrodes; and b) Centrifugal slip casting of morphologically anisotropic particles to orient the active material in the low tortuosity direction. The anisotropic slurry of LiMn2O4 will be cast into straight channel architectures to provide minimal tortuosity in the direction of lithium-ion transport. 

Date:         Thursday, June 27, 2013

Time:      8:45 A.M.

Place:    ARMS 3109

Lisa Stacey

Secretary/Development Assistant

Purdue University

School of Materials Engineering

765/494-4100