Solvent‐assisted ball milling for synthesizing solid electrolyte Li₇P₃S₁₁

Abstract

Solvent‐assisted ball milling is used to prepare the sulfide solid electrolyte Li7P3S11. Comparing with dry ball milling and simple liquid phase synthesis, solvent‐assisted ball milling can significantly promote the reaction of the starting materials from tens of hours to only several hours. When using dimethoxyethane as the assistant solvent, relatively pure Li7P3S11 with ionic conductivity of 1.0 × 10−4 S/cm can be synthesized after 8‐hour ball milling with following 2‐hour 180°C vacuum drying and 4‐hour 230°C heat treatment. It is revealed that the transition from the precursor to Li7P3S11 is a two‐step process, with an intermediate composed of a thio‐LISICON III analogous phase and an amorphous phase. This work not only provides a synthesis route of Li7P3S11 which reduces synthesis duration, but also offers an instructive insight into the phase evolution in solvent‐based synthesis process of sulfide solid electrolytes.

High Ionic Conductivity with Improved Lithium Stability of CaS- and CaI2-Doped Li7P3S11 Solid Electrolytes Synthesized by Liquid-Phase Synthesis

“…The former peak corresponded to the dissociation of the solvent–thiophosphate complex, and the latter peak originated from several reactions, namely, the formation of Li 7 P 3 S 11 and the decomposition of Li 7 P 3 S 11 into Li 3 PS 4 , Li 4 P 2 S 6 , and sulfur, which is still unclear. 13 , 26 Therefore, little free solvent in the Li 7 P 3 S 11 SE precursor dried under all the conditions remained and the weight loss for the samples dried at 80 °C for 6 h could represent the solvent in the complex. In addition, slight changes were observed depending on the drying time at 80 °C ( Figure S3d ).…”

Enhanced Air and Electrochemical Stability of Li7P3S11–Based Solid Electrolytes Enabled by Aliovalent Substitution of SnO2

“…As exhibited in Figure , the Li 7 P 3 S 11 shows a low σ of 2.7 × 10 −4 S cm −1 , which is higher than that of the reported literature with this method (1.0 × 10 −4 S cm −1 ). [ 45 ] Compared with liquid phase synthesis, solvent‐assisted ball milling can significantly promote the reaction of the raw materials from 3 days to only several hours. In contrast, with Sn and O co‐doping, the ionic conductivity increases up to the maximum of 5.3 × 10 −4 S cm −1 as the substitution amount is 0.2, which is twice of that of the pristine Li 7 P 3 S 11 .…”

“…Preparation Method: The sulfide SSEs were prepared employing solvent-assisted ball milling method using a planetary ball mill apparatus (QM-1SP2). [45] The Li 2 S (Alfa, 99.9%), P 2 S 5 (Aladdin, 99.99%), and SnO 2 (Aladdin, 99.9%) with a mole ratio of 7:(3−x):x as the raw materials were mixed in a 50 ml tungsten carbide jar, where a certain amount of acetonitrile solvent (the mass ratio is 6:1) was also added as a grinding aid. The ball milling speed and time were set as 510 rpm and 7 h, respectively.…”

Stabilizing electrode/electrolyte interface in Li-S batteries using liquid/solid Li2S-P2S5 hybrid electrolyte

“…The soaking experiment was carried out by immersing 300 mg of lithium thiophosphates xLi 2 S•(100-x)P 2 S 5 (70≤x≤75) into 5ml DME-DOL solvent (50-50,v%) for 48 h. The mixture was vigorously shaken every 8 h and finally vacuum dried at 80 o C for composition analysis by XRD and Raman spectra. As shown by the XRD patterns in the Raman spectra (Figure3b), all the five soaked SSEs display almost identical diffraction peaks which can be attributed to a crystalline phase DME-solvated Li 3 PS 4[54,55]. There appear two distinctive peaks positioned at 421cm -1 and 388 cm -1 in Figure3b, corresponding to ether-solvated PS 4 3− anion and ether-solvated vertex-shared PS 4 tetrahedral anions[54], respectively.…”