A cost-effective, ionically conductive and compressible oxychloride solid-state electrolyte for stable all-solid-state lithium-based batteries

Abstract

To enable the development of all-solid-state batteries, an inorganic solid-state electrolyte should demonstrate high ionic conductivity (i.e., > 1 mS cm−1 at 25 °C), compressibility (e.g., > 90% density under 250−350 MPa), and cost-effectiveness (e.g., < $50/kg). Here we report the development and preparation of Li1.75ZrCl4.75O0.5 oxychloride solid-state electrolyte that demonstrates an ionic conductivity of 2.42 mS cm−1 at 25 °C, a compressibility enabling 94.2% density under 300 MPa and an estimated raw materials cost of $11.60/kg. As proof of concept, the Li1.75ZrCl4.75O0.5 is tested in combination with a LiNi0.8Mn0.1Co0.1O2-based positive electrode and a Li6PS5Cl-coated Li-In negative electrode in lab-scale cell configuration. This all-solid-state cell delivers a discharge capacity retention of 70.34% (final discharge capacity of 70.2 mAh g−1) after 2082 cycles at 1 A g−1, 25 °C and 1.5 tons of stacking pressure.

Amorphous Oxyhalide Matters for Achieving Lithium Superionic Conduction

“…The resultant Li 2 ZrCl 4 O exhibited a similar diffraction pattern to that of Li 2 ZrCl 6 except for a small amount of residual Li 2 O (Figure d). Comparing Li 2 ZrCl 4 O to Li 2 ZrCl 6 , theoretically, a considerable amount of the Cl was replaced by O (33.3%), which showed a higher O substitution percentage compared to previous reports about doping O (8–21%) in the Li 2 ZrCl 6 SEs. − Nevertheless, although there is a big difference in radius between Cl – (181 pm) and O 2– (140 pm), a nonobservable peak shift appeared in the Li 2 ZrCl 4 O SE (see the magnified regions from Figure d-1–d-3). This indicated that O was not doped into the structure of crystalline hcp -Li 2 ZrCl 6 but altered the properties of the amorphous phase that increased to 69.1% in Li 2 ZrCl 4 O SE.…”

Crowding Effect-Induced Zinc-Enriched/Water-Lean Polymer Interfacial Layer Toward Practical Zn-Iodine Batteries

“…Ionic conductivity, which was calculated from the thickness and impedance, was used to detect the ion-conducting ability of the Zn-CCS polymer crowding layer, which demonstrated the highest ionic conductivity (0.12156 mS cm –1 ) with an electrodeposition time of 60 s. Following section was subsequently standardized to use samples with an electrodeposition time of 60 s. Its variation at 30–70 °C was in accordance with the Arrhenius model (correlation coefficient of R 2 = 0.94), which indicated that, kinetically, the diffusion behavior controlled the ionic transport process (Figures e and f, as well as Figure S7 in the Supporting Information). − It was further found that Zn-CCS polymer crowding layer showed excellent kinetic enhancement of Zn 2+ , which not only enhanced the Zn 2+ transference number (0.68) but also reduced the R ct and Zn 2+ desolvation activation energy (40.74 kJ mol –1 ), with which the distribution and diffusion behavior of Zn 2+ at the interface was regulated (Figures g and h, as well as Figures S8 and S9 in the Supporting Information) . In order to investigate the regulating effect of the Zn-CCS polymer crowding layer more deeply, chronoamperometry (CA) was applied to analyze the Zn deposition behavior under the three-electrodes system.…”

High-Conductivity Li2ZrCl6 Electrolytes via an Optimized Two-Step Ball-Milling Method for All-Solid-State Lithium–Metal Batteries

“…28,29 In recent years, Li 2 ZrCl 6 has garnered significant attention from researchers due to its lower cost compared to Li 6 PS 5 Cl, as well as other similar halide electrolytes. 30,31 Furthermore, Li 2 ZrCl 6 exhibits superior moisture resistance when compared to other halide compounds. 30 However, the conventional ballmilling synthesized Li 2 ZrCl 6 shows limited ionic conductivity.…”