Interfacial Ion‐Transport Mechanism of Li₇(Al_0.1)La₃Zr₂O₁₂ Solid Electrolyte Modified by using a Spark Plasma Sintering Method

Abstract

A novel interfacial in situ modification for Li7(Al0.1)La3Zr2O12 is designed and prepared by using a spark plasma sintering method. The modified interface with most grain boundary area exhibits excellent interfacial electrochemical properties. The X‐ray diffraction (XRD) and scanning electron microscope (SEM) data indicate that the interfacial modified specimen (spark plasma sintering method, 1000 °C, 5 min) with 38.2(6) nm grain diameter and 32,134 cm2/g grain boundary specific surface area has the highest ionic conductivity (8.84×10−4 S/cm−1). The lithium‐ion transmission mechanism in grain‐internal and grain boundaries is revealed by ab initio theory, using Materials Studio software. Furthermore, the first‐principles calculation data indicate that the migration barrier of Li+ at the Li7(Al0.1)La3Zr2O12 solid electrolyte grain boundary is 0.21 eV, which is only 2/3 of that in the grain internal (0.33 eV). As a result, SPS interfacial in situ processing technology can increase the grain boundary area, thereby reducing the ion transport barrier and the interfacial impedance of the material.

Reducing the Interfacial Resistance in All‐Solid‐State Lithium Batteries Based on Oxide Ceramic Electrolytes

“…A number of oxide‐based and nonoxide‐based SSEs exhibiting superb ionic conductivity have been investigated, such as Li‐β‐alumina, Li 3 N, Li 4 SiO 4 , perovskite‐type Li 3 x La 2/3−x TiO 3 (LLTO), garnet‐type Li 7 La 3 Zr 2 O 12 (LLZO) and sodium superionic conductor (NASICON)‐type Li 1.2 Al 0.2 Ti 1.8 (PO 4 ) 3 (LATP), as shown in Table . In recent studies, OCEs have shown great promise due to their chemical stability in air, high ionic conductivity of 10 −3 S cm −1 (25 °C), wide electrochemical window and excellent mechanical strength . Although the thin‐film electrolyte LiPON has a very low ionic conductivity of 10 −6 S cm −1 , the area specific resistance (ASR) of the electrolyte is as low as 10 Ω cm −2 due to its thin thickness (below 1 μm).…”

A Nanoscale Design Approach for Enhancing the Li-Ion Conductivity of the Li10GeP2S12 Solid Electrolyte

“…However, while the ion transport mechanisms in bulk LGPS have been investigated, − this is not the case for nanocrystallite effects in LGPS samples. Grain boundary resistance in sulfide solid electrolytes is generally considered to be minimized compared to that of oxide systems. − Beyond LGPS, there are several studies concerning the nanostructure of various solid electrolytes in order to reduce interfacial resistance and improve ion transport. − The influence of nanosizing crystalline samples on Li-ion conductivity has been illustrated for sulfide − and oxide − solid electrolyte materials. However, the atomistic effects of nanosizing LGPS have not been previously characterized.…”

Enhanced Li-Ion Conductivity in Nanosized Li10GeP2S12

“…Beyond LGPS, there are several studies concerning the microstructure and grain boundaries of various solid electrolytes in order to reduce interfacial resistance and improve ion transport [31][32][33][34][35][36][37][38] . The influence of nanosizing crystalline samples on Li-ion conductivity has been illustrated for sulfide [38][39][40] and oxide [41][42][43] solid electrolyte materials.…”