Extremely dense microstructure and enhanced ionic conductivity in hot-isostatic pressing treated cubic garnet-type solid electrolyte of Ga₂O₃-doped Li₇La₃Zr₂O₁₂

Abstract

A large number of pores and a low relative density that are frequently observed in solid electrolytes reduce severely their ionic conductivity and thus limit their applicability. Here, we report on the use of hot isostatic pressing (HIP) for ameliorating the garnet-type lithium-ion conducting solid electrolyte of Ga2O3-doped Li7La3Zr2O[Formula: see text] (Ga-LLZO) with nominal composition of Li[Formula: see text]Ga[Formula: see text]La3Zr2O[Formula: see text]. The Ga-LLZO pellets were conventionally sintered at 1075[Formula: see text]C for 12[Formula: see text]h, and then were followed by HIP treatment at 120[Formula: see text]MPa and 1160[Formula: see text]C under an Ar atmosphere. It is found that the HIP-treated Ga-LLZO shows an extremely dense microstructure and a significantly enhanced ionic conductivity. Coherent with the increase in relative density from 90.5% (untreated) to 97.5% (HIP-treated), the ionic conductivity of the HIP-treated Ga-LLZO reaches as high as [Formula: see text][Formula: see text]S/cm at room temperature (25[Formula: see text]C), being two times higher than that of [Formula: see text][Formula: see text]S/cm for the untreated one.

Influence of Liquid Solutions on the Ionic Conductivity of Li1.3Al0.3Ti1.7(PO4)3 Solid Electrolytes

“…The higher the relative density is, the higher the ionic conductivity is, which agrees with most researches. [19] The highest relative density is 93.5 %, which is obtained in sample #900-1075. Judging from the results of relative density, we selected several samples of 900-0, 900-1000, 900-1050 and 900-1075 to observe their microscopic morphology.…”

Composite Solid Polymer Electrolyte with Garnet Nanosheets in Poly(ethylene oxide)

“…In Figure a, the garnet nanoparticles that were calcined at 750 °C display a mixed structure of cubic and tetragonal phases, and the tetragonal phase is converted to cubic phase after calcining at 800 °C, accompanied by some impurity of Li 2 ZrO 3 . The garnet nanosheets that were calcined at 750 °C display cubic phase (PDF: 45-0109) and slight impurity of Li 2 ZrO 3 . The crystalline of cubic garnet becomes distinct as the calcined temperature increases to 800 and 850 °C, the impurity of Li 2 ZrO 3 also disappeared at higher calcined temperature, i.e., more than 750 °C.…”

All‐Solid‐State Thin Film μ‐Batteries for Microelectronics

“…Compared with amorphous type of electrolytes, there are many choices in crystalline‐structured electrolytes, such as garnet‐, [ 67 , 68 , 69 ] LISICON‐, [ 70 ] NASICON‐, [ 74 , 140 ] perovskite‐type etc.…”