Search

This review introduces solid electrolytes based on sulfide/polymer composites which are used in all‐solid‐state lithium batteries, describing the use of polymers as plasticizer, the lithium‐ion conductive channel, the preparation methods of solid‐state electrolytes (SSEs), including dry methods and wet methods with their advantages and disadvantages. In addition, the physicochemical stability of sulfide/polymer composite based solid‐state electrolytes is analyzed. The sulfide/polymer composite based solid‐state electrolyte can be utilized in lithium metal or lithium sulfur batteries. However, there are still many problems left to be solved in practical applications of these solid‐state electrolytes. In this review, several solutions are explored. Firstly, the ultra‐long life cycle of batteries can be achieved by thinning the composite electrolyte. Secondly, when sulfur is applied as the positive electrode, the thinning electrolyte can reduce polarization and other problems. Finally, an integrated battery is employed to reduce the interface impedance. By addressing these aspects, the review aims to provide valuable insights into the future development of high‐performance solid‐state electrolytes in lithium battery technology. [ABSTRACT FROM AUTHOR]

Composite solid-state electrolytes are viewed as promising materials for solid-state lithium-ion batteries due to their combined advantages of inorganic solid-state electrolytes and solid-state polymer electrolytes. In this study, the solid electrolytes Li6.7−xLa3Zr1.7−xSb0.3NbxO12 (LLZSNO) with Sb and Nb co-doping were prepared by a high-temperature solid-phase method. Results indicate that Sb/Nb co-doping causes lattice deformation in LLZO and increases the lithium vacancy concentration and conductivity of LLZO. Then, with the co-doped LLZSNO as an inorganic filler, a composite solid electrolyte of polyvinylidene fluoride-hexafluoropropylene (PVDF-HFP) was prepared with a casting method. The obtained composite solid electrolyte exhibits a high ionic conductivity of 1.76 × 10−4 S/cm at room temperature, a wide electrochemical stable window of 5.2 V, and a lithium-ion transfer number of 0.32. The Li|LiFePO4 coin battery with the composite solid electrolyte shows a high specific capacity of 161.2 mAh/g and a Coulombic efficiency close to 100% at 1 C. In addition, the symmetrical lithium battery Li|Li with the composite electrolyte could cycle stably for about 1500 h without failure at room temperature. [ABSTRACT FROM AUTHOR]

[Display omitted] The room and low-temperature performances of solid-state lithium batteries are crucial to expand their practical application. Polyethylene oxide (PEO) has received great attention as the most representative polymer electrolyte matrix. However, most PEO-based solid-state batteries need to operate at high temperature due to low room temperature ionic conductivity. Improving the ionic conductivity by adding plasticizers or reducing the crystallinity of PEO often compromises its mechanical strength. Here, an amorphous PEO-based composite solid-state electrolyte is obtained by ultraviolet (UV) polymerizing PEO and methacryloyloxypropyltrimethoxy silane (KH570)-modified SiO 2 which demonstrates both satisfactory mechanical performance and high ionic conductivity at room (3.37 × 10−4 S cm−1) and low temperatures (1.73 × 10−4 S cm−1 at 0 °C). In this electrolyte, the crystallinity of PEO is reduced through cross-linking, and therefore provides a fast Li+ ions transfer area. Moreover, the KH570-modified SiO 2 inorganic particles promote the dissociation of lithium salts by Lewis acid centers to increase the ionic conductivity. Importantly, this kind of cross-linking networks endows the final electrolyte much higher mechanical strength than the pure PEO polymer electrolyte or PEO-inorganic filler blended systems. The solid-state LiFePO 4 /Li cell assembled with this electrolyte exhibits excellent cycling performance and high capacity at room and low temperatures. [ABSTRACT FROM AUTHOR]

Composite solid-state electrolyte have good interfacial compatibility and mechanical properties, but their safety (such as easy to catch fire) and economic cost are still problems. In present work, an composite solid-state electrolyte was prepared by inserting poly(vinylidene fluoride)-based polymer electrolyte matrix into the interlayer of a low cost clay mineral-montmorillonite. The composite electrolyte exhibited remarkable characteristics, including excellent flame retardancy, high room temperature ionic conductivity of 2.28 × 10−4 S cm−1, wide electrochemical stability window of 4.8 V, high lithium-ion transference number of 0.57 and good mechanical strength of 12.58 MPa. Furthermore, LiFePO 4 -based solid-state battery, utilizing this composite solid-state electrolyte, exhibited stable cycling with discharge specific capacity of 130 mAh g−1 for over 100 cycles at a rate of 0.5C at room temperature. This successful performance demonstrated the potential of utilizing low-cost and environmentally friendly raw clay mineral materials in high energy density solid-state battery applications. • A montmorillonite-based composite solid-state electrolyte was prepared. • The composite electrolyte exhibited high ionic conductivity at room temperature. • The excellent flame retardancy was attributed to the high montmorillonite content. • Low-cost clay mineral greatly reduced the cost of solid electrolytes. [ABSTRACT FROM AUTHOR]

A high-safety composite solid-state electrolyte (CSSE) was constructed by embedding the high ionic conductivity garnet type Li 6.5 La 3 Zr 1.5 Ta 0.1 Nb 0.4 O 12 (LLZTNO) powder into a polyvinylidene fluoride (PVDF) matrix. The ionic conductivity of the CSSE containing 10% LLZTNO could reach 1.05 × 10−4 S cm−1, and the electrochemical window was extended to 4.80 V vs Li/Li+. In addition, the evolution and composition of the SEI layer were characterized by in-situ optical microscopic observation, X-ray photoelectron spectroscopy and cryogenic electron microscopy (cryo-EM). When paired with an NCM811 cathode, the batteries showed good rate cycling performance, and the discharge capacity could be maintained at 137.1 and 91.2 mAh g−1 at 0.3C and 2C after 80 and 100 cycles. The needle penetration test further demonstrated superior safety and potential applications of the PVDF-based room-temperature CSSE batteries. • A composite solid-state electrolyte with high ionic conductivity was developed. • It demonstrates a wide electrochemical window and excellent cycling performance. • The characteristics of SEI were identified by cryogenic TEM. • The Li metal battery assembled from the composite electrolyte show excellent safety. [ABSTRACT FROM AUTHOR]