Details

Autor(en) / Beteiligte

• Hamann, Tanner
• Zhang, Lei
• Gong, Yunhui
• Godbey, Griffin
• Gritton, Jack
• McOwen, Dennis
• Hitz, Gregory
• Wachsman, Eric

Titel

The Effects of Constriction Factor and Geometric Tortuosity on Li‐Ion Transport in Porous Solid‐State Li‐Ion Electrolytes

Ist Teil von

• Advanced functional materials, 2020-04, Vol.30 (14), p.n/a

Ort / Verlag

Hoboken: Wiley Subscription Services, Inc

Erscheinungsjahr

2020

Quelle

Wiley Online Library

Beschreibungen/Notizen

• 3D focused ion beam tomography is used to analyze the microstructures of Li‐ion conducting Li6.75La2.75Ca0.25Zr1.5Nb0.5O12 (LLCZN) garnet porous electrolytes with different levels of porosity and the theoretical effective bulk conductivities of the electrolyte are calculated based on LLCZN volume fraction, constriction factor, geometric tortuosity, and percolation factor. The experimentally measured effective bulk conductivities are consistently lower than the theoretical values when assuming constant bulk conductivity, suggesting the bulk conductivity of the LLCZN decreased with increasing porosity. This work highlights the importance of understanding the full effects of altering the microstructure of solid‐state electrolytes, as this will play a key role in advancing Li‐ion battery technology to higher energy and power densities. 3D microstructures of porous Li6.75La2.75Ca0.25Zr1.5Nb0.5O12 solid electrolytes are investigated using focused ion beam tomography. Electrolyte volume fraction and bottlenecks are primary factors limiting ion transport with tortuosity having a lesser effect. Measured effective bulk conductivities are lower than theoretical values calculated from 3D microstructures and decrease exponentially with increasing porosity and corresponding surface area, apparently from greater Li volatilization during sintering.