Ultra-fast high temperature sintering (UHS) of Li1.5Al0.5Ge1.5P3O12 electrolyte: A rationalization of the heating schedule

Ultrafast Crystallization and Sintering of Li1.5Al0.5Ge1.5(PO4)3 Glass and Its Impact on Ion Conduction

“…In addition, despite the contact with carbon strips, the LAGP UHS sample showed no evidence of graphite contamination, which was responsible for the blackening of crystalline LAGP treated by UHS. 13 The relative densities of the samples are 80% and 78% for the conventional and UHS pellets, respectively; the former value is consistent with the literature on glassy LAGP sintered at 750 °C. 42 SEM micrographs of fractured cross sections are displayed in Figure 3c.…”

“…Raman spectra of LAGP conventional and LAGP UHS samples (Figure S6) are consistent with those reported in the literature for pure LAGP, , further supporting the absence of detectable impurities. In addition, despite the contact with carbon strips, the LAGP UHS sample showed no evidence of graphite contamination, which was responsible for the blackening of crystalline LAGP treated by UHS …”

“…Li 1.5 Al 0.5 Ge 1.5 (PO 4 ) 3 (LAGP), a widely used NASICON-type solid-state electrolyte, is typically produced on an industrial scale by a melt-quenching technique in glass form. Then, LAGP is crystallized with further heat treatment at T > 600 °C. ,, To achieve a solid electrolyte, crystalline LAGP powders are sintered at high temperatures (800–900 °C for 6 to 12 h). ,− However, crystallization and sintering are lengthy processes occurring at high temperatures, which may cause Li loss, leading to the precipitation of secondary phases. , Furthermore, the high energy requirements of sintering contribute to a significant portion of the solid-state battery preparation costs. , …”

“…For the first time, LAGP was sintered and crystallized by UHS directly from glass powders in a single step taking just 180 s. Further, the strategy represents a significant advance as LAGP pellets are typically produced from crystalline LAGP using either conventional methods or UHS. ,− , It should be noted that, thanks to the short processing time of UHS, Li mass loss and the related formation of unwanted secondary phases were suppressed . The influence of UHS annealing on the sintering and crystallization processes of LAGP was also investigated, as these are sensitive to the heating rate .…”

“…11,13−16 However, crystallization and sintering are lengthy processes occurring at high temperatures, which may cause Li loss, leading to the precipitation of secondary phases. 13,17 Furthermore, the high energy requirements of sintering contribute to a significant portion of the solid-state battery preparation costs. 18,19 Recently, several rapid techniques for ceramic sintering characterized by fast heating rates and short processing times have been explored, including cold sintering, 20−22 a fieldassisted sintering technique, 23 flash sintering, 24,25 spark plasma sintering, 26 and ultrafast high-temperature sintering (UHS).…”