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[Display omitted] • The in-situ gel of SPE ensures interface compatibility and scalable preparation. • InPc was conducive to improving ionic conductivity and suppressing shuttle effect. • InPc induces a protective layer on the surface of the lithium. • The resulting pouch Li-S cell delivered an energy density of 325.5 Wh kg−1. Lithium-sulfur batteries (LSBs) are currently being investigated as a potential candidate for high-energy–density rechargeable batteries. However, the notorious shuttle effect and uncontrolled dendrite growth posed problems for the practical applications of LSBs. Here, a new solid polymer electrolyte (SPE) was developed by in-situ polymerization of 1,3-dioxolane (DOL) in the presence of a multifunctional indium phthalocyanine (PDOL@InPc). The InPc endows the SPE with improved ionic conductivity and merit inhibition of the shuttle effect, in addition to being an effective additive for inducing uniform Li deposition by reconstructing the electric field at the interface. The characteristics of ionic migration in PDOL@InPc were quantified, and agreement between experiment and simulation established a relationship between macroscopic characteristics and molecular-level processes. The interfacial side reaction was controlled by the PDOL@InPc electrolyte, which also improved the distribution of the Li+ flux for dense Li deposition. Li symmetrical batteries designed with PDOL@lnPc can withstand a current density of up to 0.5 mA cm−2 and cycle reliably for 1500 h. The PDOL@InPc electrolyte displayed a high ionic conductivity at room temperature of 3.7 mS cm−1 and a significant Li+ transference number of 0.63. The resulting Li-S battery (Li|PDOL@lnPc|Sulfur) delivered a significant 325.5 Wh kg−1 of energy density at 0.2 C (1 C = 1000 mA g−1) at the level of the multilayer-pouch cell under an extremely low electrolyte of 3.5 g g−1 Sulfur and high loading of 8.0 mg cm−2. This work provides a feasible strategy for the widespread implementation of LSBs with increased safety and a longer lifetime. [ABSTRACT FROM AUTHOR]

For the preparation of high-density ceramic electrolytes, researchers prefer cold or hot isostatic pressing method, which is not cost effective because of the ultra-high pressure and poor productivity. In this paper, we present a novel “self-consolidation” method to prepare dense cubic Al-doped Li 7 La 3 Zr 2 O 12 (LLZO) without the assist of pressing. The relative density of LLZO bulk sample is about 93–96%, and the 0.10 mol Al-doped sample with the purest cubic structure possesses the highest total ionic conductivity of 1.41 × 10 − 4 S cm − 1 at 30 °C, which is comparable to the conductivities of the samples prepared by traditional high-pressure methods. Furthermore, a LLZO crystal unit cell model is constructed and the self-consolidation mechanism for LLZO from crystal unit cell to bulk is explored. The surface tension of the molten Li compounds acts as the intrinsic power for the self-consolidation. This work demonstrates a facile, productive and reliable route for the preparation of dense cubic LLZO, and provides an important insight into the microscopic consolidation mechanism of ceramic electrolytes. [ABSTRACT FROM AUTHOR]

Abstract Garnet-like Li 7 La 3 Zr 2 O 12 electrolytes with Nb doping are synthesized by self-consolidation method. Different from conventional methods such as cold or hot isostatic pressing, not any pressing assistance is employed throughout the preparation process. Although the preparation process is dramatically simplified, both density and ionic conductivity of the obtained samples are enhanced. Nb-doped content plays a key role in the sintering of the packed precursor powders and in the structure stabilization of the obtained bulk samples. The optimized 0.60 mol Nb-doped sample with relative density of 94%, fine particle boundaries, and solitary cubic structure possesses the maximum total ionic conductivity of 5.22 × 10−4 S cm−1 at 30 °C, which is comparable to the highest reported value of the samples prepared by conventional pressing methods. This work verifies that self-consolidation strategy is effective, reliable, and productive for the preparation of cubic Li 7 La 3 Zr 2 O 12 electrolyte, which would significantly facilitate the development of ceramic electrolyte membrane technology. [ABSTRACT FROM AUTHOR]

Li 5 La 3 Nb 2 O 12 (LLNO) is a typical garnet-like solid electrolyte with solitary cubic structure. However, its ionic conductivity is relatively low due to the low relative density when prepared by cold isostatic pressing method, which usually involves high-pressure machines, poor productivity, tedious pressing operations, and low density. In this paper, self-consolidation method is developed to sinter dense LLNO electrolyte. Although not any pressing operations are employed in the entire process, the relative density of LLNO is promoted up to 95%, which is much higher than the reported values of 45–80%. SEM images reveal that the sample is built by huge particles in size of 80 μm indicating that there are few boundaries in the sample. Moreover, a rich content of Li-Al-O compounds is detected out in the boundary areas, which may act as sintering aids for the sample to consolidate automatically. According to the highest density, the bulk ionic conductivity of LLNO sample reaches up to 1.61 × 10 −4  S cm −1 at 30 °C, which is in the same order of magnitude as the value of cubic Li 7 La 3 Zr 2 O 12 electrolyte. This work verifies the self-consolidation mechanism for the sintering of ceramic electrolytes and could significantly facilitate the development of LLNO membrane technology. [ABSTRACT FROM AUTHOR]

Garnet-type Li 5 La 3 Ta 2 O 12 (LLTaO) solid electrolyte is a potential candidate component for future all-solid-state batteries due to its extraordinary stability against the reaction with molten lithium. In contrast with traditional cold isostatic pressing (CIP) method, which generally pursues ultra-high pressure, this paper tries to enhance the density and ionic conductivity of LLTaO by self-consolidation strategy without the assistance of any pressing operations. A LLTaO bulk with a relative density of 95% is obtained. SEM images reveal that the bulk sample is assembled by large dense particles in size of tens of microns indicating that the interstitial space among the particles has been dramatically minimized. Accordingly, the total ionic conductivity and the bulk ionic conductivity at 30 °C are promoted up about one order of magnitude higher to 2.63 × 10 −5 S cm −1 and 1.41 × 10 −4 S cm −1 , respectively. Moreover, the lithium ionic migration network in the crystalline unit cell of LLTaO is first explored from its assembled way. A hexagon-like basic unit with tetrahedral Li1 joint sites and Li1- - Li1 edges is identified. The tetrahedral Li1 sites act as crucial junctions for the transportation of lithium ions. This work would significantly stimulate the development of LLTaO electrolyte membrane technology. [ABSTRACT FROM AUTHOR]

For conventional preparation methods of Li 7 La 3 Zr 2 O 12 (LLZO) solid state electrolytes, there is a stereotype that higher density always comes from higher pressure enforced upon the LLZO pellets. In this paper, a different way with an auto-consolidation mechanism is provided and discussed. No pressing operations are employed during the whole preparation process. Due to the surface tension of liquid melted Li 2 O at sintering temperature, LLZO particles could aggregate together freely and automatically. The preparation process for dense LLZO is greatly simplified. A dense tetragonal LLZO with high relative density about 93% has been prepared successfully by this auto-consolidation method. And there are no voids observed in the SEM images. At 30 °C, the total conductivity is about 5.67 × 10 −5 S cm −1 , which is the highest one for tetragonal LLZO in the reported issues, even two times higher than that prepared by hot-pressing method. The activation energy for total conductivity is ∼0.35 eV atom −1 at 30–120 °C, slightly lower than the previous reported values. This work sheds light on the understanding of the consolidation mechanism for solid electrolytes and suggests a reliable route to syhthesize cemanic solid electrolytes. [ABSTRACT FROM AUTHOR]