The Mechanism of Decreasing Resistance by SDX™ in Lithium Ion Battery

Abstract

SDX ® which is surface coated aluminum current collector (AL) with carbon black and organic binder, makes a cell resistance lower and adhesion between cathode active material and AL stronger, so as to improve battery performances dramatically. The cell resistance was separated simply into electronic resistance and ionic resistance. We successfully separated the electronic resistance into material resistance and interface resistance between cathode active material and AL. And then, we independently measured the material resistance and the interface resistance by Electrode Resistance Meter (HIOKI E.E. CORPORATION) which can separate electrode resistance into material and interface resistance. In this paper, more detailed examinations were carried out, and the mechanism of decreasing resistance by SDX ® in lithium ion battery (LIB) was tried to be clarified.

Dissecting the Solid Polymer Electrolyte–Electrode Interface in the Vicinity of Electrochemical Stability Limits

“…This is especially important since the electrode composition and morphology will affect the current response . The original purpose of the carbon coating is to create good electronic contact and adhesion between the electrode composite and current collector, and it has a negligible capacity contribution. , The LFP reference was embedded in PCL:LiTFSI via hot pressing at 90 °C; see the Experimental Section for details. To guarantee that the polymer electrolyte did not chemically decompose during hot pressing, the thermal stability was evaluated using thermal gravimetric analysis (TGA).…”

“…XPS of the pristine Cu−C electrode reveals C 1s peaks at 284.0, 285.0, 286.0, and 288.1 eV According to the manufacturer, the carbon black is held together using an organic binder, most likely containing nitrogen as indicated by the peak at 399.8 eV. 28,29 Two Cu 2p peaks are also observed at 932.7 and 934. 23 The carbon peaks are accompanied by two additional O 1s peaks at 532 and 533.8 eV (marked in red), corresponding to CO and C−O.…”

Quantitative Analyses of the Interfacial Properties of Current Collectors at the Mesoscopic Level in Lithium Ion Batteries by Using Hierarchical Graphene

“…Moreover, it can be seen that the entire electrode resistance on the b-Al current collector is fairly dominated by their interfacial resistance, whereas the interfacial resistance on the hG-Al current collector is virtually eliminated nonetheless (see Figure e). Previous results have reported that the R interface value of a carbon-coated Al current collector is reduced by only ∼1 order of magnitude . Compared with as-synthesized hierarchical graphene interlayer, the carbon-based interlayer is relatively thick (on the micrometer scale) with insulating binders used, which thus leads to its restrained capability in reducing the interfacial resistance.…”

“…Thus, for the amelioration of LIB, it is of primary significance to revisit the mesoscopic electrode configuration with a focus on the interfacial properties of current collector. Roughened Al current collector, , carbon-coated Al foil , (or its derivatives of carbon nanotube-coated Al foil or graphene-coated Al foil , ), and vertical graphene current collectors, etc., have been proposed to enhance the CC/EM interface. Despite these progress achieved, few works are dedicated to the quantitative analysis as to the interfacial properties at the mesoscopic level.…”

“…Given that the electric resistance of the entire electrode is composed of the interfacial resistance ( R interface ) and material resistance ( R material ), we further measured the R interface and R material to probe how the interlayer functions quantitatively. As shown in Figure d, the R material values of the electrodes were independent of the CC used and can be efficiently reduced with increased conductive additive content.…”