Bulk and interface-strengthened Li7P2.9Sb0.1S10.65O0.15I0.2 electrolyte via dual-source doping for all-solid-state lithium-sulfur batteries

Abstract

Sulfide solid electrolyte is a promising candidate for the development of high-energy lithium-sulfur (Li-S) batteries. However, the concurrent improvement of ionic conductivity, bulk air stability, and compatibility of the electrolyte/electrode interface of sulfide solid electrolyte remains a huge challenge. Herein, we propose a dual-source doping (Sb 2 O 3 and LiI) strategy to prepare a multifunctional sulfide solid electrolyte. Sb 2 O 3 can broaden the transmission path of lithium ions and improve the bulk stability, and LiI can inhibit the generation of lithium dendrites and reduce the electrolyte/ electrode resistance. Therefore, the sulfide solid electrolyte can be strengthened in terms of its bulk and interface, thus exhibiting a high ionic conductivity of 1.69 × 10 −3 S cm −1 at 30°C, high air stability, and high electrochemical stability with lithium metal. On this basis, the as-prepared all-solid-state Li-S batteries (ASSLSBs) can exhibit a high specific discharge capacity after being cycled at 0.05 C for 100 cycles at room temperature (833 mA h g −1 ) or 60°C (949 mA h g −1 ). This work provides a rational scheme for the preparation of practical sulfide solid electrolytes and high-performance ASSLSBs.

Synergistic Interfacial Optimization for High-Sulfur-Content All-Solid-State Lithium–Sulfur Batteries

“…As shown in Figure c, the Li 7 P 3 S 11 and Li 7 P 2.9 Y 0.1 S 10.8 I 0.2 sulfide solid electrolytes are tested at a constant current charge/discharge of 0.1 mA cm –2 . After 16 h of testing, the voltage of the Li/Li 7 P 3 S 11 /Li symmetric battery suddenly drops due to lithium dendrite penetration and short circuit inside the battery. , In contrast, the Li/Li 7 P 2.9 Y 0.1 S 10.8 I 0.2 /Li battery remained steady for 270 h before short circuit, showing about 17 times prolonged lifetime after doping. In more common scenarios, the lithium–indium alloy would be chosen as the anode in ASSLSBs to achieve better cyclic stability.…”

Li metal anode interface in sulfide‐based all‐solid‐state Li batteries

“…As shown in Table 2, doping elements can be divided into halogen and metal elements, which can be used to replace S and P elements in SSEs, respectively. Some studies have substituted S and P simultaneously 33,143–148 …”

“…Some studies have substituted S and P simultaneously. 33,[143][144][145][146][147][148] Li argyrodites, a promising family of SSEs, are formed by substituting the S element with halogen (F, Cl, Br, and I). 160 Furthermore, various modified Li argyrodites have been designed and prepared.…”