The Morphology of Battery Electrodes with the Focus of the Conductive Additives Paths

Abstract

Model experiments, in which active material in the electrode is replaced with insulating ceramic particles, are used to show the importance of pure conductive additives network. Ceramic particles are chosen with particle diameter of 10 and 3 μm. Coatings with similar loading and varying levels of carbon black, graphite and polyvinylidene fluoride are fabricated, analyzed regarding electronic conductivity and investigated with a new "quasi" in-situ SEM compression method. The electronic conductivity strongly depends on porosity, inactive material amount and distribution. SEM/EDX images showed that coatings with 10 μm particles have higher porosity and denser network of conductive additives compared to 3 μm particles. Therefore, the conductive additives and binder amount should be adjusted based on the particle size distribution.

The interaction of consecutive process steps in the manufacturing of lithium-ion battery electrodes with regard to structural and electrochemical properties

“…However, our physical concept focuses on the changes during the porosity variations, and also describes the importance of the electron pathways throughout the entire electrode. More details regarding the significance of long-range pathways are published in our previous work [64].…”

Improvement of Lithium‐Ion Battery Performance by Two‐Layered Slot–Die Coating Operation

“…SEM‐EDS mapping analysis used by Indrikova et al. was then adopted for this study . It was a semiquantitative analytical method for elements present in a compound and showed the characteristic spectral position of an element.…”

“…Indrikova et al. studied the importance of conductive network structure in an electrode plate by replacing some conductive additives with insulating ceramic particles . They found that there was a strong correlation between electronic conductivity and plate porosity with the same amount of inactive additives and network structure.…”

Alternative Sample Preparation Method for Large-Area Cross-Section View Observation of Lithium Ion Battery

“…As most anode and cathode materials are susceptible to moisture and have a porous structure, mechanical polishing cannot be used as the large-area cross-section sampling preparation method. Instead, ion-milling method using a cross-section polisher (CP) and a focused ion beam (FIB) can be used (Ebner et al, 2013;Indrikova et al, 2015;Liu et al, 2016;Otoyama et al, 2016). FIB is often useful in observing specific areas by finely controlling the Ga + ion source.…”

“…While it cannot perform milling on a specific area, its large beam size allows for large-area milling. Therefore, it is extremely important to select a cross-section sampling method that meets the aims of the analysis of secondary batteries used (Deng et al, 2017;Indrikova et al, 2015;Kawaguchi et al, 2017;Kim et al, 2008;Otoyama et al, 2016). This study explained a sampling method for cross-section imaging analysis based on the research objectives by conducting a comparative analysis of the sample analysis results using CP and FIB, which are two most widely used cross-section sampling methods for SEM imaging analysis.…”