Chemical and Electrochemical Characterization of Hot-Pressed LiPSCl Solid State Electrolyte: Operating Pressure-Invariant High Ionic Conductivity.

Sulfide solid state electrolytes (SSE) are among the most promising materials in the effort to replace liquid electrolytes, largely due to their comparable ionic conductivities. Among the sulfide SSEs, Argyrodites (LiPSX, X=Cl, Br, I) further stand out due to their high theoretical ionic conductivity (~1×10 S cm) and interfacial stability against reactive metal anodes such as lithium. Generally, solid state electrolyte pellets are pressed from powder feedstock at room temperature, however, pellets fabricated by cold pressing consistently result in low bulk density and high porosity, facilitating interfacial degradation reactions and allowing dendrites to propagate through the pores and grain boundaries.

Self-Formulated Na-Based Dual-Ion Battery Using Nonflammable SO -Based Inorganic Liquid Electrolyte.

Sodium secondary batteries have gained much attention as alternative power sources to replace lithium secondary batteries. However, some technical issues must be solved to ensure their success. Here, a highly safe and cost-effective Na-based dual-ion battery system employing self-formulated CuCl cathode material starting from a mixture of Cu and NaCl in conjunction with a nonflammable NaAlCl ·2SO inorganic liquid electrolyte is demonstrated.

Lithium-Ion Intercalation into Graphite in SO-Based Inorganic Electrolyte toward High-Rate-Capable and Safe Lithium-Ion Batteries.

Herein, we have identified that lithium ions in an SO-based inorganic electrolyte reversibly intercalate and deintercalate into/out of graphite electrode using ex situ X-ray diffraction and various electrochemical methods. X-ray photoelectron spectroscopy shows that the solid electrolyte interphase on the graphite electrode is mainly composed of inorganic compounds, such as LiCl and lithium sulfur-oxy compounds. Graphite electrode in SO-based inorganic electrolyte has stable capacity retention up to 100 cycles and outstanding rate capability performance.

Dendrite-Free Li Metal Anode for Rechargeable Li-SO Batteries Employing Surface Modification with a NaAlCl-2SO Electrolyte.

Dendritic growth of a Li metal anode during cycling is one of major issues to be addressed for practical application of Li metal rechargeable batteries. Herein, we demonstrate that surface modification of Li metal with a Na-containing SO electrolyte can be an effective way to prevent dendritic Li growth during cell operation. The surface-modified Li metal anode exhibited no dendritic deposits even under a high areal capacity (5 mA h cm) and a high current density (3 mA cm), whereas the unmodified anode showed typical filamentary Li deposition.

Dendrite-Free Polygonal Sodium Deposition with Excellent Interfacial Stability in a NaAlCl₄-2SO₂ Inorganic Electrolyte.

Room-temperature Na-metal-based rechargeable batteries, including Na-O2 and Na-S systems, have attracted attention due to their high energy density and the abundance of sodium resources. Although these systems show considerable promise, concerns regarding the use of Na metal should be addressed for their success. Here, we report dendrite-free Na-metal electrode for a Na rechargeable battery, engineered by employing nonflammable and highly Na(+)-conductive NaAlCl4·2SO2 inorganic electrolyte, as a result, showing superior electrochemical performances to those in conventional organic electrolytes.

A room-temperature sodium rechargeable battery using an SO2-based nonflammable inorganic liquid catholyte.

Sodium rechargeable batteries can be excellent alternatives to replace lithium rechargeable ones because of the high abundance and low cost of sodium; however, there is a need to further improve the battery performance, cost-effectiveness, and safety for practical use. Here we demonstrate a new type of room-temperature and high-energy density sodium rechargeable battery using an SO2-based inorganic molten complex catholyte, which showed a discharge capacity of 153 mAh g(-1) based on the mass of catholyte and carbon electrode with an operating voltage of 3 V, good rate capability and excellent cycle performance over 300 cycles. In particular, non-flammability and intrinsic self-regeneration mechanism of the inorganic liquid electrolyte presented here can accelerate the realization of commercialized Na rechargeable battery system with outstanding reliability.