Grain-boundary conduction in gadolinia-doped ceria: The effect of SrO addition

This study examined the effect of adding SrO on the grain-boundary conduction of Ce(0.9)Gd(0.1)O(1.95) (gadolinia-doped ceria) containing 500 ppm SiO(2). The apparent grain-boundary resistivity at 300 degrees C decreased drastically from 746.7 to 0.90-1.97 k Omega cm upon doping with >= 1 mol % SrO, while the grain-interior resistivity increased gradually from 3.1 to 11.6 k Omega cm as the SrO concentration was increased up to 5 mol %. Therefore, doping with 1 mol % SrO resulted in the minimum total resistivity. The electron probe X-ray microanalysis and the analysis of the lattice parameters suggest that the 140-500-fold enhancement in the grain-boundary conduction is attributed to the scavenging of the highly resistive siliceous phase by the SrO-containing phase. (C) 2008 The Electrochemical Society

Electrolyte-free graphite electrode with enhanced interfacial conduction using Li+-conductive binder for high-performance all-solid-state batteries

Electrodes supported by conductive binders are expected to outperform ones with inert binders that potentially disturb electronic/ionic contacts at interfaces. Unlike electron-conductive binders, the employment of Li+ conductive binders has attracted relatively little attention due to the liquid electrolyte (LE)-impregnated electrode configuration in the conventional lithium-ion batteries (LIBs). Herein, an all-solid-state electrolyte-free electrode where electrolyte components are completely excluded is introduced as a new tactical electrode construction to evaluate the effectiveness of the Li+-conductive binder on enhancing the interfacial conduction, ultimately leading to high-performance all-solid-state batteries (ASSBs). Conductive lithium carboxymethyl cellulose (Li-CMC) is prepared through an optimized two-step cation-exchange reaction without physical degradation. The electrolyte-free graphite electrode employing Li-CMC as the binder shows strikingly improved areal and volumetric capacity of 1.46 mAh cm(-2) and 490 mAh cm(-3) at a high current rate (1.91 mA cm(-2)) and 60 C which are far superior to those (1.07 mAh cm(-2) and 356.7 mAh cm(-3)) using Na-CMC. Moreover, systematic monitoring of the lithiation dynamics inside the electrolyte-free electrode clarifies that the interfacial Li+ conduction is greatly promoted in the Li-CMC electrode. Complementary analysis from in-depth electrochemical measurements and multiscale simulations verifies that serious internal resistance from impeded interparticle diffusion by inert binders can be substantially mitigated using Li-CMC.N

Electrolyte-free graphite electrode with enhanced interfacial conduction using Li+-conductive binder for high-performance all-solid-state batteries

Electrodes supported by conductive binders are expected to outperform ones with inert binders that potentially disturb electronic/ionic contacts at interfaces. Unlike electron-conductive binders, the employment of Li+-conductive binders has attracted relatively little attention due to the liquid electrolyte (LE)-impregnated electrode configuration in the conventional lithium-ion batteries (LIBs). Herein, an all-solid-state electrolyte-free electrode where electrolyte components are completely excluded is introduced as a new tactical electrode construction to evaluate the effectiveness of the Li+-conductive binder on enhancing the interfacial conduction, ultimately leading to high-performance all-solid-state batteries (ASSBs). Conductive lithium carboxymethyl cellulose (Li-CMC) is prepared through an optimized two-step cation-exchange reaction without physical degradation. The electrolyte-free graphite electrode employing Li-CMC as the binder shows strikingly improved areal and volumetric capacity of 1.46 mAh cm???2 and 490 mAh cm???3 at a high current rate (1.91 mA cm???2) and 60 ??C which are far superior to those (1.07 mAh cm???2 and 356.7 mAh cm???3) using Na-CMC. Moreover, systematic monitoring of the lithiation dynamics inside the electrolyte-free electrode clarifies that the interfacial Li+ conduction is greatly promoted in the Li-CMC electrode. Complementary analysis from in-depth electrochemical measurements and multiscale simulations verifies that serious internal resistance from impeded interparticle diffusion by inert binders can be substantially mitigated using Li-CMC