Search

In this work, a SiO2 doped polyvinyl alcohol/polyethylene glycol (PVA/PEG) gel polymer electrolyte (PVA/PEG-SiO2) was constructed via an ice-crystal template for zinc-ion batteries. The SiO2 and the three-dimensional porous skeleton make it have excellent ionic conductivity and mechanical strength, and inhibit the growth of dendrites. The assembled ZIBs exhibit excellent rate performance and cycle stability, making it a promising electrolyte membrane candidate for flexible wearable electronics. [ABSTRACT FROM AUTHOR]

The slow Li+ transport rate in the thick sulfur cathode of the Li--S battery affects its capacity and cycling performance. Herein, Fe-doped highly ordered mesoporous silica material (Fe--HSBA-15) as a sulfur carrier of the Li--S battery shows high ion conductivity (1.10 mS cm-1) and Li+ transference number (0.77). The Fe--HSBA-15/S cell has an initial capacity of up to 1216.7 mA h g-1 at 0.2C and good stability. Impressively, at a high sulfur load of 4.34 mg cm-2, the Fe--HSBA-15/S cell still maintains an area specific capacity of 4.47 mA h cm-2 after 100 cycles. This is because Fe--HSBA-15 improves the Li+ diffusion behavior through the ordered mesoporous structure. Theoretical calculations also confirmed that the doping of iron enhances the adsorption of polysulfides, reduces the band gap and makes the catalytic activity stronger. [ABSTRACT FROM AUTHOR]

A gel polymer electrolyte (GPE) supported by a polyimide (PI) nanofiber membrane with Li6.5La3Zr1.5Ta0.5O12 (LLZTO) nanoparticles (PI/LLZTO/GPE) shows excellent flexibility and electrochemical properties, the ionic conductivity is 1.87 mS cm−1 and the Li+ transfer number is 0.64 at room temperature. The assembled Li metal battery with a LiFePO4 (LFP) cathode retains a 56.4 mA h g−1 discharge capacity at 10C. [ABSTRACT FROM AUTHOR]

Germanium nanowire (GeNW) electrodes have shown great promise as high-power, fast-charging alternatives to silicon-based electrodes, owing to their vastly improved Li ion diffusion, electron mobility and ionic conductivity. Formation of the solid electrolyte interphase (SEI) on the anode surface is critical to electrode performance and stability but is not completely understood for NW anodes. Here, a systematic study characterizing pristine and cycled GeNWs in charged and discharged states with SEI layer present and removed is performed using Kelvin probe force microscopy in air. Correlating changes in the morphology of the GeNW anodes with contact potential difference mapping at different cycles provides insight into SEI layer formation and growth, and the effect of the SEI on battery performance. [ABSTRACT FROM AUTHOR]

Traditional metal–organic-frameworks (MOFs) have been extensively studied and applied in various fields across chemistry, biology and engineering in the past decades. Recently, a family of emerging MOF liquids and glasses have gained ever-growing research interests owing to their fascinating phase transitions and unique functions. To date, a growing number of MOF crystals have been found to be capable of transforming into liquid and glassy states under external stimuli, which overcomes the limitations of MOF crystals by introducing functional disorder in a controlled manner and offering some desirable properties. This review is dedicated to compiling recent advances in the fundamental understanding of the phase and structure evolution during crystal melting and glass formation in order to give insights into the underlying conversion mechanism. Benefiting from the disordered metal–ligand arrangement and free grain boundaries, various functional properties of liquid and glassy MOFs including porosity, ionic conductivity, and optical/mechanical properties are summarized and evaluated in detail, accompanied by the structure–property correlation. At the same time, their potential applications are further assessed from a developmental perspective according to their unique functions. Finally, we summarize the current progress in the development of liquid/glassy MOFs and point out the serious challenges as well as the potential solutions. This work provides perspectives on the functional applications of liquid/glassy MOFs and highlights the future research directions for the advancement of MOF liquids and glasses. [ABSTRACT FROM AUTHOR]

A Li6PS5Cl-rich composite is prepared using a PEG-borate ester solid-state polymer electrolyte (BSPE). BSPE is a highly accessible compound with high ionic conductivity and excellent electrochemical stability against Li metal. Thereby, the stability of the Li6PS5Cl-rich composite with BSPE improved significantly. [ABSTRACT FROM AUTHOR]

The thrust towards a higher energy density and safer alternative to traditional-liquid-electrolyte-based batteries has driven academic and industrial efforts in developing solid-state batteries and particularly solid-state Li/Na–metal batteries (SSLMBs/SSNMBs). Despite research on solid electrolytes seemingly being on a perpetual trajectory, there have been considerable critical issues to be overcome for solid electrolytes, including the insufficient ionic conductivity, low ion-transference number, and poor compatibility with lithium–metal anodes and intercalation cathodes. This feature article sets out efforts to regulate the cubic structure of garnet-type electrolytes, along with a discussion of the solid-solution synthetic approach to produce garnet-type and NASICON (sodium super ion conductor)-type electrolytes, followed by the synthetic strategy for sintering dense nano-grained NASICON-type electrolytes. Next, the mechanochemical synthetic approach and hybrid electrolyte design strategy to mitigate the issues associated with PEO-based composite electrolytes are presented. Finally, the advancement of promising polymeric electrolytes is discussed. We end the perspective with an opinion on the future research in this area. [ABSTRACT FROM AUTHOR]

A ternary-salt solid polymer electrolyte (TS-SPE) consisting of LiPF6-LiTFSI-LiFSI salts and poly(1,3-dioxolane) is created by in situ polymerization. The TS-SPE possesses high ionic conductivity, high Li+ ion transference number, and stable SEI with low interfacial impedance, thereby realizing excellent rate performance and long-life stability in Li metal batteries. [ABSTRACT FROM AUTHOR]

Polyethylene oxide (PEO) based polymer electrolytes have been widely used in solid-state lithium batteries (SSBs) owing to the high solubility of lithium salt, favourable ionic conductivity, flexibility for improved interfacial contact and scalable processing. In this work, we summarize the main limitations remaining to be solved before the large-scale commercialization of PEO-based SSBs, including (1) improving ionic conductivity toward high-rate performance and lower operating temperature, (2) enhancing mechanical strength for improved lithium dendrite resistance and large-scale processing, (3) strengthening electrochemical stability to match high energy density electrodes with high voltage, and (4) achieving high thermal stability toward safe operation. Meanwhile, the characterization methods to investigate the ion transportation mechanism, lithium dendrite growth and decomposition reaction are also discussed. [ABSTRACT FROM AUTHOR]

A thin free-standing composite solid electrolyte film (CSE, ∼15 μm) is prepared by a tape casting and solution infusion method, which owns a high ionic conductivity (2.76 × 10−4 S cm−1 at 25 °C) and a wide electrochemical stability window (4.8 V vs. Li+/Li). The CSE-based solid-state lithium metal batteries with the LiCoO2 cathode present good cycling stability and capacity retention with a 4.5 V cut-off voltage. [ABSTRACT FROM AUTHOR]

All-solid-state lithium batteries (ASSLBs) have attracted increasing attention recently because they are more safe and have higher energy densities than conventional lithium-ion batteries. In particular, ASSLBs composed of Ni-rich cathodes, sulphide-based solid-state electrolytes (SSEs) and lithium metal anodes have been regarded as the most competitive candidates. Ni-rich cathodes possess high operating potential, high specific energy and low cost, and sulphide-based SSEs have excellent ionic conductivity comparable to that of liquid electrolytes. However, severe parasitic reactions and chemo-mechanical issues hinder their practical application. Herein, the structure, ionic conductivity, chemical or electrochemical stability and mechanical property of sulphide-based SSEs are introduced. Critical interfacial problems between Ni-rich cathodes and sulphide-based SSEs, including chemical or electrochemical parasitic reactions, space charge layer effect, mechanical stress and contact loss, are summarised. The corresponding solutions including coating layer construction and structure design are expounded. Finally, the remaining challenges are discussed, and perspectives are outlined to provide guidelines for the future development of ASSLBs. [ABSTRACT FROM AUTHOR]

The addition of a small amount of plant biomass-based lignin causes a large improvement in the ionic conductivity of composite polymer electrolytes at room temperature, which can be fabricated easily in a low carbon way for use in future all-solid-state battery applications. [ABSTRACT FROM AUTHOR]

A polymer electrolyte with high elasticity and high performance is prepared by IN SITU polymerization. The polymer electrolyte is amorphous and has a high ionic conductivity of 7.9 × 10−4 S cm−1 and good elasticity. The discharge capacity of Li/LiFePO4 in the 100th cycle is 133.90 mA h g−1 (0.5C, 25 °C). [ABSTRACT FROM AUTHOR]

We report a rare-earth triflate catalyst Sc(OTf)3 for the ring-opening polymerization of 1,3-dioxolane and the in situ production of a quasi-solid-state poly(1,3-dioxolane) electrolyte, which not only demonstrates a superior ionic conductivity of 1.07 mS cm−1 at room temperature, but achieves dendrite-free lithium deposition and a high Coulombic efficiency of 92.3% over 200 Li plating/striping cycles. [ABSTRACT FROM AUTHOR]

An alternating copolymer-based poly(ionic liquid) (PIL) was synthesized and blended with PVDF-HFP to obtain solid-state polymer electrolytes with both high mechanical strength and high ionic conductivity. Structural analysis reveals that the high performance is attributed to the nanophase separation of PVDF-HFP with a PIL in the nanometric scale, which benefits from an alternating polymer architecture of the PIL. [ABSTRACT FROM AUTHOR]

This communication reports a novel hyperbranched polymer with poly(ethylene glycol)9 segments and carboxylate groups. The combined advantages of single-ion conduction and a hyperbranched structure make the as-prepared polymers very promising as a solid-state polymer electrolyte for lithium ion batteries, by showing high ionic conductivity up to 1.2 × 10−4 S cm−1 at 85 °C, a high lithium transference number (tLi+) of 0.86, and simultaneously, a stable potential window up to 4.8 V versus Li+/Li. [ABSTRACT FROM AUTHOR]

A hybrid gel–solid-state polymer electrolyte has been used as the separator and an electrolyte for lithium oxygen batteries. It can not only avoid electrolyte evaporation but also protect the lithium metal anode during reactions over long-term cycling. Due to its high ionic conductivity and low activation energy, excellent cycling performance is demonstrated, in which the terminal voltage is higher than 2.2 V after 140 cycles at 0.4 mA cm−2, with a capacity of 1000 mA h g(composite)−1. [ABSTRACT FROM AUTHOR]