Ultrafast Crystallization and Sintering of Li_1.5Al_0.5Ge_1.5(PO₄)₃ Glass and Its Impact on Ion Conduction

Abstract

is among the most promising solid electrolytes for the next generation's all-solid-state lithium batteries. However, preparing LAGP electrolytes is timeand energy-intensive. In this work, LAGP glassy powders were sintered and crystallized in 180 s by ultrafast high-temperature sintering (UHS) under conditions attractive for continuous industrial processes (i.e., ambient pressure and atmosphere). The fast heating rates characteristic of UHS significantly delay crystallization, potentially decoupling crystallization and sintering. Furthermore, electrochemical impedance spectroscopy (EIS) characterizations reveal that LAGP sintered and crystallized by UHS has an ionic conductivity of 1.15 × 10 −4 S/cm, slightly lower than conventionally annealed samples (1.75 × 10 −4 S/cm). The lower conductivity can be attributed to poorer intergrain contact. To overcome this issue, additives such as B 2 O 3 and Li 3 BO 3 are used, resulting in ∼2 and ∼5 times higher grain boundary conductivity for LAGP+1 wt % B 2 O 3 and LAGP+1 wt % Li 3 BO 3 , respectively, compared to LAGP. Overall, this work provides insights into unraveling the impact of UHS sintering on the LAGP Li + conduction mechanism.

Melt-casted Li1.5Al0.3Mg0.1Ge1.6(PO4)3 glass ceramic electrolytes: A comparative study on the effect of different oxide doping

“…The overall resistance of the systems was in fact nearly halved, resulting in ionic conductivity values of 1.8 × 10 −4 S cm −1 (0.18 mS cm −1 ) and 2.1 × 10 −4 S cm −1 (0.21 mS cm −1 ) at 20 °C in the presence of Y 2 O 3 and B 2 O 3 , respectively. To our knowledge, these are amongst the highest ionic conductivity values reported so far [ 18 , 23 , [27] , [28] , [29] , [30] ] in the relevant literature for LAGP-based type of ceramic systems. Actually, an absolute comparison is usually not straightforward, considering that different instruments and instrumental setups are used to measure samples prepared in different laboratories, but still these ionic conductivity values are remarkable for LAGP-type ceramics, which normally show lower ionic conductivities than the parent LATP-based systems [ 14 , 24 , 32 , 34 , 35 , 46 ].…”

“…Over the past decades, the addition of different dopants in different concentrations in this family of electrolytes was investigated, mainly in terms of resulting ionic mobility [ 18 , [21] , [22] , [23] , [24] , [25] , [26] ]. The idea that, for a given number of free Li + ions available for conduction, Li + ion conductivity is not only dependent on the thermally-activated dynamics described by the Arrhenius law, but also on microstructural and morphological features, was already qualitatively postulated in previous studies [ [27] , [28] , [29] , [30] , [31] ], including our precedent work [ 32 ] on boron-oxide-added LAGTP. Nevertheless, no detailed evidence and demonstration of this were given before the study of Vyalikh et al [ 33 ], who demonstrated that one of the most impactful factors behind this is grain cohesion.…”

Innovations in Electric Current-Assisted Sintering for SOFC: A Review of Advances in Flash Sintering and Ultrafast High-Temperature Sintering

“…UHS, despite its relatively nascent development, is already finding applications across various fields. It is currently utilized in the production of SOFC, solid electrolytes [145,146], polymer-derived ceramic nanocomposites (PDC-NC) [147], thermal barrier coating materials [41,148,149], thermoelectric nanomaterials [150], metal and alloy materials [151], biomaterials [152], and quartz glass [153], etc. FS, with its broad applicability, extends beyond SOFCs and solid electrolytes [154] to include semiconductor materials [55], metalliclike conductors such as borides, nitrides, and carbides of transition metals [113], armor [155,156], biomaterials [157,158], the joining of dissimilar materials [159,160], and nuclear fuel [161][162][163].…”

NASICON-type Li_1.5Al_0.5Ge_1.5(PO₄)₃ Containing Amorphous Phase for Solid Li-Ion Conductor

“…Efforts have been made to enhance the sinterability of LAGP by incorporating Li 3 BO 3 as a sintering aid and by applying pressure for a shorter duration during the sintering process. 7 The activation energy required for Li + conduction in crystallized LAGP was approximately 0.4 eV. However, the presence of sintering aids hampers ionic conduction, which poses a significant challenge.…”