Boosting the interfacial superionic conduction of halide solid electrolytes for all-solid-state batteries

• Published in: Nature communications Vol. 14; no. 1; p. 2459
• Main Authors: Kwak, Hiram, Kim, Jae-Seung, Han, Daseul, Kim, Jong Seok, Park, Juhyoun, Kwon, Gihan, Bak, Seong-Min, Heo, Unseon, Park, Changhyun, Lee, Hyun-Wook, Nam, Kyung-Wan, Seo, Dong-Hwa, Jung, Yoon Seok
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 28.04.2023; Nature Publishing Group; Nature Portfolio
• Subjects: 119/118; 140/131; 147/28; 639/301/299; 639/301/299/891; 639/638/161; 639/638/263/915; 639/638/675; Compatibility; Conduction; Conductivity; Density functional theory; Electrolytes; Humanities and Social Sciences; Interface stability; Ion currents; Ions; Lithium; Lithium oxides; MATERIALS SCIENCE; Molten salt electrolytes; multidisciplinary; Nanocomposites; NMR; Nuclear magnetic resonance; Science; Science (multidisciplinary); Sodium; Solid electrolytes; Solid state; Synchrotron radiation; Synchrotrons; Transition metal oxides; Voltage stability; Zirconium dioxide
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-023-38037-z

Designing highly conductive and (electro)chemical stable inorganic solid electrolytes using cost-effective materials is crucial for developing all-solid-state batteries. Here, we report halide nanocomposite solid electrolytes (HNSEs) ZrO 2 (-ACl)-A 2 ZrCl 6 (A = Li or Na) that demonstrate improved ionic conductivities at 30 °C, from 0.40 to 1.3 mS cm −1 and from 0.011 to 0.11 mS cm −1 for Li + and Na + , respectively, compared to A 2 ZrCl 6 , and improved compatibility with sulfide solid electrolytes. The mechanochemical method employing Li 2 O for the HNSEs synthesis enables the formation of nanostructured networks that promote interfacial superionic conduction. Via density functional theory calculations combined with synchrotron X-ray and 6 Li nuclear magnetic resonance measurements and analyses, we demonstrate that interfacial oxygen-substituted compounds are responsible for the boosted interfacial conduction mechanism. Compared to state-of-the-art Li 2 ZrCl 6 , the fluorinated ZrO 2 −2Li 2 ZrCl 5 F HNSE shows improved high-voltage stability and interfacial compatibility with Li 6 PS 5 Cl and layered lithium transition metal oxide-based positive electrodes without detrimentally affecting Li + conductivity. We also report the assembly and testing of a Li-In||LiNi 0.88 Co 0.11 Mn 0.01 O 2 all-solid-state lab-scale cell operating at 30 °C and 70 MPa and capable of delivering a specific discharge of 115 mAh g −1 after almost 2000 cycles at 400 mA g −1 . Compositional tuning is a standard procedure to improve the ionic conductivity of inorganic superionic conductors. Here, the authors report (electro)chemical stable composite halide solid electrolytes applying a nanostructure approach that promotes interfacial superionic conductivity.