Bongki Son

Measurement and Analysis of Adhesion Property of Lithium-Ion Battery Electrodes with SAICAS

The adhesion strength of lithium-ion battery (LIB) electrodes consisting of active material, a nanosized electric conductor, and a polymeric binder is measured with a new analysis tool, called the Surface and Interfacial Cutting Analysis System (SAICAS). Compared to the conventional peel test with the same electrode, SAICAS gives higher adhesion strength owing to its elaborate cutting-based measurement system. In addition, the effects on the adhesion property of the polymeric binder type and content, electrode density, and measuring point are also investigated to determine whether SAICAS provides reliable results. The findings confirm SAICAS as an effective and promising tool to measure and analyze the adhesion properties of LIB electrodes.

Graphite/Silicon Hybrid Electrodes using a 3D Current Collector for Flexible Batteries

A flexible hybrid anode from graphite and thin film silicon is realized by the concept of a 3D sandwich current collector by the combination of micro-contact printing and RF magnetron sputtering. Flexible lithium-ion batteries with a new hybrid anode demonstrate not only enhanced specific capacity but also improved rate capability compared to that of a conventional graphite anode under bending deformation.

Effect of LiCoO 2 Cathode Density and Thickness on Electrochemical Performance of Lithium-Ion Batteries

The consequences of electrode density and thickness for electrochemical performance of lithium-ion cells are investigated using 2032-type coin half cells. While the cathode composition is maintained by 90:5:5 (wt.%) with active material, Super-P electric conductor and polyvinylidene fluoride polymeric binder, its density and thickness are independently controlled to 20, 35, 50 um and 1.5, 2.0, 2.5, 3.0, 3.5 g , respectively, which are based on commercial lithium-ion battery cathode system. As the cathode thickness is increased in all densities, the rate capability and cycle life of lithium-ion cells become significantly worse. On the other hand, even though the cathode density shows similar behavior, its effect is not as high as the thickness in our experimental range. This trend is also investigated by cross-sectional morphology, porosity and electric conductivity of cathodes with different densities and thicknesses. This work suggests that the electrode density and thickness should be chosen properly and mentioned in detail in any kinds of research works.