Correlating Li-Ion Cathode Conductivity with Battery Performance

_{KEYWORDS: Tunneling AFM; Data Cubes; Li-ion Battery Research; SEI Formation; Battery Electrodes; Battery Cathode; Power Density; Battery Lifetime}

Electrical data-cube (DCUBE) modes combine imaging, nanomechanics, and full electrical spectroscopy at every pixel, producing a highly reproducible, integrated 3D data set. This big-data approach delivers higher dimensional data that can be sliced along any axis or plane.

This application brief describes the use of DCUBE-TUNA mode on a battery cathode consisting of Li metal oxide, polymer binder, and conductive carbon nanoparticles. We present and analyze sample data extracted from the resultant DCUBE-TUNA data set, including 15×15 μm topography, modulus, and conductivity images.

Readers can expect to understand the advantages of using DCUBE-TUNA to:

• Dissect spatial component distribution;
• Differentiate regions of high conductivity where carbon black particles are embedded in binder material;
• Identify the presence of "dead" metal oxide grains; and
• Investigate the influence of nanoscale mechanical and electrical properties on capacity and failure.