Quasi-solid State Electrolyte Research Articles

Quasi-Solid-State Electrolyte Induced by Metallic MoS2 for Lithium-Sulfur Batteries.

Lithium-sulfur (Li-S) batteries are a promising high-energy-density technology for next-generation energy storage but suffer from an inadequate lifespan. The poor cycle life of Li-S batteries stems from their commonly adopted catholyte-mediated operating mechanism, where the shuttling of dissolved polysulfides results in active material loss on the sulfur cathode and surface corrosion on the lithium anode. Here, we report in situ formation of a quasi-solid-state electrolyte (QSSE) on the metallic 1T phase molybdenum disulfide (MoS2) host that extends the lifetime of Li-S batteries. We find that the metallic 1T phase MoS2 host is able to initiate the ring-opening polymerization of 1,3-dioxolane (DOL), forming an integrated QSSE inside batteries. Nuclear magnetic resonance analysis reveals that the QSSE consists of ∼13% liquid DOL in a solid polymer matrix. The QSSE efficiently mediates sulfur redox reactions through dissolution-conversion chemistry while simultaneously suppressing polysulfide shuttling. Therefore, while ensuring high sulfur utilization, it avoids degradation of both electrodes, as well as the concomitant electrolyte consumption, leading to enhanced cycling stability. Under a practical lean electrolyte condition (electrolyte-to-sulfur ratio = 2 μL mg-1), Li-S pouch cell batteries with the QSSE demonstrate a capacity retention of 80.7% after 200 cycles, much superior to conventional liquid electrolyte cells that fail within 70 cycles. The QSSE also enables Li-S pouch cell batteries to operate across a wider temperature range (5 to 45 °C), together with improved safety under mechanical damage.

Revealing the quasi-solid-state electrolyte role on the thermal runaway behavior of lithium metal battery

Replacing flammable non-aqueous organic liquid electrolyte (LE) with high thermal stability solid-state electrolyte (SSE) is considered to overcome the safety issues in lithium metal batteries (LMBs). However, both inorganic solid-state batteries (SSBs) with high mechanical strength and thermal stability, as well as flexible polymer-based SSBs, are not proven to be inherently safe yet. Currently, the reliability of SSBs still require continuous scientific verification. In this work, quasi-solid-state electrolyte (QSE) with practical application prospects was prepared through in-situ polymerization method. The effects of QSE and LE on the thermal runaway behavior of LMBs were systematically compared from four levels: electrolyte, electrolyte/electrode interface, coin cells, and pouch cells. The results showed that higher thermal stability of QSE was conducive for improving the reliability of quasi-solid-state batteries (QSBs) under different abused conditions. The stable and dense solid electrolyte interface (SEI) in QSB could not only inhibit the severe side-reactions of LMBs during cycling at elevated temperature, but also enhance the decomposition temperature with dead lithium. QSE's lower reaction activity towards Li reduced the exothermic reaction inside the battery had been proven to increase the self-exothermic onset temperature and thermal runaway trigger temperature of LMBs, which promoted the safety performance of LMBs. Thus, this study revealed the thermal runaway mechanism of QSE in LMBs, and provided a theoretical guideline for safe QSBs design.

A Thiol Branched 3D Network Quasi Solid-State Polymer Electrolyte Reinforced by Covalent Organic Frameworks for Lithium Metal Batteries.

Quasi solid-state polymer electrolytes (QSPEs) are particularly attractive due to their high ionic conductivity and excellent safety for lithium metal batteries (LMBs). However, it is still a great challenge for QSPEs to achieve strong mechanical strength and high electrochemical performance simultaneously. Herein, a QSPE (SCOF-PEP-PEA) using a covalent organic framework (COF) containing abundant allyl groups (SCOF) as a rigid porous filler as well as a cross-linker to reinforce the polymer network is reported. Benefitting from the unique 3D nanonetwork structure and abundant lithiophilic functional groups, SCOF-PEP-PEA QSPE exhibits high ionic conductivity (4.0 × 10-4 S cm-1) and high lithium-ion transference number (0.82) at room temperature. Moreover, SCOF-PEP-PEA QSPE displays much improved mechanical strength compared to PEP-PEA QSPE (AFM Young's modulus: 453 vs 36MPa). As a result, the Li/LFP full cell with SCOF-PEP-PEA QSPE shows great rate performance of 141 mAh g-1 at 1C and delivers a high specific capacity retention of 92% after 220 cycles at 0.5 C (60 °C). This work provides a new strategy to design and prepare high-performance QSPEs with COFs as porous organic filler, and further expand the application of COFs for energy storage applications.

Application of advanced Wide-Temperature range and flame retardant “Leaf-Vein” Structured functionality composite Quasi-Solid-State electrolyte

Currently the advancement of lithium batteries have led to their widespread adoption in cutting-edge applications, with a heightened focus on their stability and safety in extreme environments. Traditional liquid electrolytes present challenges such as flammability, leakage, and limited operating temperature ranges, impeding the progress of electrochemical energy storage devices. Quasi-solid-state electrolytes(QSE) have emerged as a promising solution to overcome these limitations. Hydrogel electrolytes have garnered significant research attention due to their rapid ion conductivity, flexibility, functionality, low cost, and environmental compatibility. However, hydrogel electrolytes still face challenges such as narrow electrochemical window, low mechanical strength, and susceptibility to freezing. Herein, this study introduces a novel “leaf-vein” structured QSE, fabricated by combining a flexible hydrogel (UV in-situ curing) with a robust nanofiber network (electrospinning). The original QSE exhibits flame retardant (30 min non-flammability), broad electrochemical window (4.2 V), freeze resistance (- 60 °C) with 0.25 MPa, and self-healing capabilities. The assembled full battery demonstrates exceptional electrochemical stability at ultra-low temperatures. This distinctive structure of the QSE indicates novel insights and directions for the design and material selection of advanced electrolyte materials, enabling secure applications of electrochemical energy storage in specialized domains particularly deep space and polar exploration.

Composite Quasi-Solid-State Electrolytes with Organic-Inorganic Interface Engineering for Fast Ion Transport in Dendrite-Free Sodium Metal Batteries.

Quasi-solid-state electrolytes (QSSE) are a promising candidate for addressing the limitations of liquid and solid electrolytes. However, different ion transport capacities between liquid solvents and polymers can cause localized heterogeneous distribution of Na+ fluxes. In addition, the continuous side reactions occurring at the interface between QSSE and sodium anode lead to uncontrollable dendrites growth. Herein, a novel strategy is designed to integrate the composite electrospun membrane of Na3Zr2Si2PO12 and poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) into QSSE, aiming to introduce new fast ion conducting channels at the organic-inorganic interface. The efficient ion transfer pathways can effectively promote the homogenization of ion migration, enabling composite QSSE to achieve an ultrahigh ionic conductivity of 4.1 mS cm-1 at room temperature, with a Na+ transference number as high as 0.54. Moreover, the PVDF-HFP is preferentially reduced upon contact with the sodium anode to form a "NaF-rich" solid electrolyte interphase, which effectively suppresses the growth of dendrites. The synergistic combination of multiple strategies can realize exceptional long-term cycling stability in both sodium symmetric batteries (≈700h) and full batteries (2100 cycles). This study provides a new insight for constructing high performance and dendrite-free solid-state sodium metal batteries.

Mns-MWCNT Composite, as a Superior Electrode Material for Asymmetric Flexible Quasi Solid-State Supercapacitors

Nowadays, renewable and sustainable energy sources are being explored and promoted to curb global pollution and to solve the issue of depleting fossil fuel resources. However, these renewable energy sources are intermittent in supply, therefore, it becomes necessary to store them for future usage. The traditional storage devices for electrical energy storage are different kinds of batteries but the sluggish performance of batteries, use of toxic heavy metals, issues pertaining to safety and low cycling efficiency are some of its major drawbacks. Recent proliferation of portable, wearable and flexible electronics and adoption of electric vehicles have forced the scientists to look for fast charging, light weight, leak proof, safe, toxic material free, durable energy storage devices like supercapacitors. Supercapacitors possess fast charge-discharge characteristics, high cycling stability and eco-friendliness in comparison to batteries. But they suffer from extremely low energy density (<10 Wh kg-1), high cost, bulk size, high self-discharge and significant drop in power density while increasing its energy density. The rational synthesis of electrode-materials has a significant impact on the development of high-performance electrodes for energy storage devices. Traditionally semiconducting materials like transition metal oxides are used as pseudocapacitive materials but transition metal oxides have very low electronic and ionic conductivity. Recently, transition metal sulfides, another class of semiconductors, are being investigated as they exhibit better conductivity and reaction kinetics compared to oxides. In this work, α-MnS is selected as an alternative to transition metal oxides. α-MnS is the most stable polymorph among other possible crystal structures of MnS, and has a hexagonal sheet like structure along with high operational potential window than many other metal sulfides. Although it is more conducting than transition metal oxides, it still needs conductivity enhancers like activated carbon, graphene, multiwall carbon nanotubes (MWCNT) etc. External mixing of conductivity enhancers is not effective enough to enhance the conductivity. Hence, MWCNT is mixed during the synthesis step to have a better bonding with α-MnS and create high conductivity channels. α-MnS + MWCNT composite shows a specific capacitance of 115 F g-1 at 1 A g-1 in 3 M KOH electrolyte under 3 electrode configuration. α-MnS + MWCNT composite is deposited on flexible conducting carbon cloth as cathode material and Vulcan carbon is deposited on carbon cloth as anode material. A mixture of poly vinyl alcohol PVA+ 3 M KOH is used as the gel type electrolyte. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), cyclic voltammetry (CV), galvanostatic charge discharge (GCD), electrochemical impedance spectroscopy (EIS), cycling stability are performed to characterize the active material and the device performance. The assembled device shows a potential window of 1.4 V, alongside a specific capacitance of 27.7 F g-1 at 1 A g-1 and with 80% of capacity retention after 10,000 cycles. These results prove that transition metal sulfides can be viable alternative materials for supercapacitor application. This quasi-solid state or gel type electrolyte significantly reduces the conductivity and specific capacitance. Enhancing the ionic conductivity of the gel and finding out the optimum thickness of gel electrolyte layer between the electrodes are expected to open new pathways in enhancing the performance of the device. Figure 1

Toward high-performance ionic liquid-based quasi-solid-state electrolytes: Tunable electrochemical properties by introducing suitable diluents

Superior to conventional liquid electrolytes, incombustible ionic liquids (ILs) with wide electrochemical stability windows show privilege to endow quasi-solid-state electrolyte (QSE) with benign interfacial contact with both metallic Li and high-voltage cathode, which bodes well for implementation of high-performance solid-state Li metal battery. But regardless of its merits, the inherent high-viscosity and frail interphase chemistry of IL towards cathodes still jeopardize ionic conductivity within QSE and even crossing the interface, and should be overcame. Herein, we creatively introduce N, N-Dimethyltrifluoroacetamide (FDMAC) into QSE fabrication, design a quasi-solid-state electrolyte (QSE-EF) by hybridizing FDMAC/EMImFSI-based IL mixture and nano-LLZTO@PVDF-HFP. This FDMAC with well compatibility to IL, significantly decreases the viscosity but without sacrificing noncombustible feature. With the aid of FDMAC, QSE-EF exhibits fast ion-conducting and high Li+ transference number. More importantly, FDMAC also contributes to tuning interphase chemistry, and therefore, the high compatibilities of both QSE-EF|Li and QSE-EF|NCM622 interfaces are fulfilled involving profitable CEI&SEI establishment. Consequently, the assembled NCM622|QSE-EF|Li cell delivers outstanding electrochemical behaviors even at 4.4 V high voltage. 1.0 Ah NCM811ǁLi pouch cell also shows satisfactory energy density (350 Wh·kg−1) with negligible capacity loss. This work provides a feasible strategy to circumvent inherent defect of ionic liquid in QSE, and emphasizes the importance of tuning compatible interfacial chemistry in further QSE design.

Confining Ionic Liquids in Developing Quasi-Solid-State Electrolytes for Lithium Metal Batteries.

The concept of confining ionic liquids (ILs) in developing quasi-solid-state electrolytes (QSSEs) has been proposed, where ILs are dispersed in polymer networks/backbones and/or filler/host pores, forming the so-called confinement, and great research progress and promising research results have been achieved. In this review, the progress and achievement in developing QSSEs using IL-confinement for lithium metal batteries (LMBs), together with advanced characterizations and simulations, were surveyed, summarized, and analyzed, where the influence of specific parameters, such as IL (type, content, etc.), substrate (type, structure, surface properties, etc.), confinement methods, and so on, was discussed. The confinement concept was further compared with the conventional one in other research areas. It indicates that the IL-confinement in QSSEs improves the performance of electrolytes, for example, increasing the ionic conductivity, widening the electrochemical window, and enhancing the cycle performance of the assembled cells, and being different from those in other areas, that is, the IL-confinement concept in the battery area is in a broad extent. Finally, insights into developing QSSEs in LMBs with the confinement strategy were provided to promote the development and application of QSSE LMBs.

Integration of a Flexible, Stretchable, Environment-Benign, and Highly Conductive PVA/H3PO4 Hydrogel as a Quasi Solid-State Electrolyte in Reduced Graphene Oxide Supercapacitors

Integration of a Flexible, Stretchable, Environment-Benign, and Highly Conductive PVA/H₃PO₄ Hydrogel as a Quasi Solid-State Electrolyte in Reduced Graphene Oxide Supercapacitors

Suppressing Dendrite Growth with Eco-Friendly Sodium Lignosulfonate Additive in Quasi-Solid-State Li Metal Battery.

The application of lithium metal batteries is limited by the drawbacks of safety problems and Li dendrite formation. Quasi-solid-state electrolytes (QSSEs) are the most promising alternatives to commercial liquid electrolytes due to their high safety and great compatibility with electrodes. However, Li dendrite formation and the slow Li+ diffusion in QSSEs severely hinder uniform Li deposition, thus leading to Li dendrite growth and short circuits. Herein, an eco-friendly and low-cost sodium lignosulfonate (LSS)-assisted PVDF-based QSSE is proposed to induce uniform Li deposition and inhibit Li dendrite growth. Li symmetric cells with 5%-LSS QSSE possess a high Li+ transfer number of 0.79, and they exhibit a long cycle life of 1000 h at a current density/areal capacity of 1 mA cm-2/5 mAh cm-2. Moreover, due to the fast electrochemical dynamics endowed by the improved compatibility of the electrodes and fast Li+ diffusion, the LFP/5%-LSS/Li full cells still maintain a high capacity of 110 mAh g-1 after 250 cycles at 6C. This work provides a novel and promising choice that uses eco-friendly LSS as an additive to PVDF-based QSSE in Li metal batteries.

Fast Lithium Ion Transport Pathways Constructed by Two-Dimensional Boron Nitride Nanoflakes in Quasi-Solid-State Polymer Electrolyte.

Quasi-solid-state electrolytes (QSSEs) are gaining huge popularity because of their significantly improved safety performance over nonaqueous liquid electrolytes and superior process adaptability over all-solid-state electrolytes. However, because of the existence of liquid molecules, QSSEs typically have low lithium ion transference numbers and compromised thermal stability. In this work, we present the fabrication of a well-rounded QSSE by introducing hexagonal boron nitride nanoflakes (BNNFs) as an inorganic filler in a poly(vinylene carbonate) matrix. BNNFs, in contrast to most inorganic fillers used as anion trappers, are used to build fast lithium ion transport pathways directly on their two-dimensional surfaces. We confirm the attractive coupling between lithium ions and BNNFs, and we confirm that with the help of BNNFs, lithium ions can migrate with less damping and a lower transport energy barrier. As a result, the designed electrolyte exhibits good ion transportability, promoted fire retardancy, and good compatibility with lithium metal anodes and commercial cathodes.

Ordered and Fast Ion Transport of Quasi‐solid‐state Electrolyte with Regulated Coordination Strength for Lithium Metal Batteries

AbstractPolymer based quasi‐solid‐state electrolyte (QSE) has attracted great attention due to its assurance for high safety of rechargeable batteries including lithium metal batteries (LMB). However, it faces the issue of low ionic conductivity of electrolyte and solid‐electrolyte‐interface (SEI) layer between QSE and lithium anode. Herein, we firstly demonstrate that the ordered and fast transport of lithium ion (Li+) can be realized in QSE. Due to the higher coordination strength of Li+ on tertiary amine (−NR3) group of polymer network than that on carbonyl (−C=O) group of ester solvent, Li+ can diffuse orderly and quickly on −NR3 of polymer, significantly increasing the ionic conductivity of QSE to 3.69 mS cm−1. Moreover, −NR3 of polymer can induce in situ and uniform generation of Li3N and LiNxOy in SEI. As a result, the Li||NCM811 batteries (50 μm Li foil) with this QSE show an excellent stability of 220 cycles at ≈1.5 mA cm−2, 5 times to those with conventional QSE. LMBs with LiFePO4 can stably run for ≈8300 h. This work demonstrates an attractive concept for improving ionic conductivity of QSE, and also provides an important step for developing advanced LMB with high cycle stability and safety.

Ordered and Fast Ion Transport of Quasi-solid-state Electrolyte with Regulated Coordination Strength for Lithium Metal Batteries.

Polymer based quasi-solid-state electrolyte (QSE) has attracted great attention due to its assurance for high safety of rechargeable batteries including lithium metal batteries (LMB). However, it faces the issue of low ionic conductivity of electrolyte and solid-electrolyte-interface (SEI) layer between QSE and lithium anode. Herein, we firstly demonstrate that the ordered and fast transport of lithium ion (Li+ ) can be realized in QSE. Due to the higher coordination strength of Li+ on tertiary amine (-NR3 ) group of polymer network than that on carbonyl (-C=O) group of ester solvent, Li+ can diffuse orderly and quickly on -NR3 of polymer, significantly increasing the ionic conductivity of QSE to 3.69 mS cm-1 . Moreover, -NR3 of polymer can induce in situ and uniform generation of Li3 N and LiNx Oy in SEI. As a result, the Li||NCM811 batteries (50 μm Li foil) with this QSE show an excellent stability of 220 cycles at ≈1.5 mA cm-2 , 5 times to those with conventional QSE. LMBs with LiFePO4 can stably run for ≈8300 h. This work demonstrates an attractive concept for improving ionic conductivity of QSE, and also provides an important step for developing advanced LMB with high cycle stability and safety.

Multilayer composite nanofibrous film accelerates the Li+ diffusion for quasi-solid-state lithium-ion batteries

The rational design of dense and flexible solid-state electrolytes (SSEs) with interface compatibility is still challenging. Here, we report a three-layer dense 3D nanofibrous matrix (PCOF) by constructing a nanofiber framework combining polyacrylonitrile (PAN) and fast Li-ion conductor covalent organic frameworks (COFs) by electrospinning method. PCOF film can maintain an extraordinary electrolyte/electrode interface and an interconnected ion-conduction pathway, accelerating Li+ diffusion. The PCOF quasi-solid-state electrolyte (QSSE) has high oxidative stability (4.70 V, versus Li+/Li) and ion conductivity of 2.94×10−4 S cm−1 at room temperature. Lithium-ion battery based on PCOF QSSE with LiFPO4 (LFP) cathode exhibits outstanding rate characteristics and cycling stability. This multi-layer composite strategy will start a new area of QSSEs lithium-ion electrolytic devices, and simultaneously accelerate the design of electrolytes featuring a wide range of properties.

Stable LiF-Rich Electrode-Electrolyte Interface toward High-Voltage and High-Energy-Density Lithium Metal Solid Batteries.

Lithium-rich layered oxide (LRLO) materials have attracted significant attention due to their high specific capacity, low cost, and environmental friendliness. However, owing to its unique capacity activation mechanism, the release of lattice oxygen during the first charge process leads to a series of problems, such as severe voltage decay, poor cycle stability, and poor rate performance. Herein, a fluorinated quasi-solid-state electrolyte (QSSE) via a simple thermal polymerization method toward lithium metal batteries with LRLO materials is reported. The well-designed QSSE exhibits an ionic conductivity of 6.4 × 10-4 S cm-1 at 30 °C and a wide electrochemical stable window up to 5.6V. Most importantly, XPS spectra demonstrate the generation of a LiF-rich electrode-electrolyte interface (EEI), where the in situ generated LiF provides strong protection against the structural degradation of LRLO materials and directs the uniform plating/stripping behaviors of lithium-ions to inhibit the formation of lithium dendrites. As a result, LRLO/QSSE/Li batteries exhibit excellent rate performance and demonstrate a large initial capacity for 209.7mA h g-1 with a capacity retention of 80.8% after 200 cycles at 0.5C. This work provides a new insight for the LiF-rich EEI design of safe, high-performance quasi-solid-state lithium metal batteries.

Hollow-Particles Quasi-Solid-State Electrolytes with Biomimetic Ion Channels for High-Performance Lithium-Metal Batteries.

Solid-state electrolytes (SSEs) are the core material of solid-state lithium metal batteries (SLMBs), which are being researched urgently owing to their high energy and safety. Both high ionic conductivity and excellent cycling stability remain the primary goal of solid-state electrolytes. Herein, inspired by K+ /Na+ ion channels in cell membrane of eukaryotes, a novel hollow UiO-66 with biomimetic ion channels based on quasi-solid-state electrolytes (QSSEs) is designed. The hollow UiO-66 spheres containing biomimetic ion channels can spontaneously combine anions and incorporate more lithium ions, creating improved ionic conductivity (1.15 × 10-3 S cm-1 ) and lithium-ion transference number (0.70) at room temperature. The long-term cycling of symmetric batteries and COMSOL simulations demonstrate that this biomimetic strategy enables uniform ion flux to suppress Li dendrites. Furthermore, the Li metal full cells paired with LiFePO4 cathode exhibit excellent cycling stability and rate performance. Consequently, the strategy of designing biomimetic QSSEs opens up a new path for developing high-performance electrolytes for SLMBs.

Effect of D-limonene additive in copper redox-based quasi-solid-state electrolytes on the performance of dye-sensitized solar cells

In dye-sensitized solar cells (DSSCs), the copper redox mediator has been proven to enhance power conversion efficiency (PCE) due to the fairly low driving force for dye regeneration. In this work, we prepared six blended biopolymer-based electrolytes (E1 to E6) to regenerate N3 Dye absorbed in TiO2 for dye-sensitized solar cell application. The regeneration behavior of three different electron-withdrawing substituents on 2-(pyridin-2-yl)− 1 H-benzo[d]imidazole ligands coordinated with copper metal, its forms [Cu(mpimb)2]1+/2+ (methyl 4-((2-(pyridin-2-yl)− 1 H-benzo[d]imidazol-1-yl)methyl) benzoate), [Cu(pbimb)2]1+/2+ (4-((2-(pyridin-2-yl)− 1 H- benzo[d]imidazol-1-yl)methyl) benzonitrile) and [Cu(ptpbi)2]1+/2+ (2-(pyridin-2-yl)− 1(4-(trifluoromethyl)benzyl)− 1 H-benzo[d]imidazole). Commencing their electrochemical and photophysical properties determines the molecular orbital energy level of the complex. A quasi-solid-state electrolyte (QSSE) medium is blended in a biopolymer host (pectin and 2-hydroxyethylcellulose). Additionally, a comparison study has been performed between commercially available pyridine-based-additive [tert-butyl pyridine (TBP)], and a bio-organic compound extracted from orange peel waste (1-methyl-4-(prop-1-en-2-yl) cyclohex-1-ene (limonene)) used as an additive material. Using these newly designed copper redox mediators and additives, the six sets of DSSCs devices has constructed. The cell structure is assembled as TiO2/N3 dye/electrolyte (E1 to E6)/Pt. Among the fabricated devices, C1 and C2 redox couples [Cu(ptpbi)2]1+/2+ having CF3 substituent exhibit maximum Voc and Jsc. Interestingly, the device with limonene additive exhibited PCE up to 4.4 %, whereas with TBP, it showed 4.0 % efficiency. The PCE results of the C2 device sustained some electrochemical factors such as Bulk Resistance (Rb =142.0 Ω), Recombination Resistance (Rrec = 191.4 Ω), Charge Transfer Resistance (Rct = 98.84 Ω), Chemical capacitance (Cμ = 7.882 μF), Ionic Conductivity (σ = 2.816 ×10−04 S cm−1), electron lifetime (τn = 16.24 μs), Diffusion length (Ln =1.39 × 10−01 mm).

The construction of quasi-solid state electrolyte with introduction of Li6.4La3Zr1.4Ta0.6O12 to suppress lithium polysulfides’ shuttle effect in Li-S batteries

Lithium polysulfides (LiPSs) as intermediate products of Li-S batteries (LSBs) are easily dissolved into liquid electrolyte, which will shorten the cycling lifespan, hinder the rate capability, and confront severe self-discharge. Herein, we report a quasi-solid state electrolyte based on introduction of Li6.4La3Zr1.4Ta0.6O12 (LLZTO) into poly(ethylene oxide) (PEO), which possesses ionic conductivity of 0.8 × 10−3 S cm−1 at ambient condition. The LSBs with this quasi-solid state electrolyte exhibit desirable electrochemical behaviors and mitigated self-discharge property.

Quasi-solid-state electrolytes - strategy towards stabilising Li|inorganic solid electrolyte interfaces in solid-state Li metal batteries

Solid-state batteries (SSBs) based on inorganic solid electrolytes (ISEs) are considered promising candidates for enhancing the energy density and the safety of next-generation rechargeable lithium batteries. However, their practical application is frequently hampered by the high resistance arising at the Li metal anode/ISE interface. Herein, a review of the conventional solid-state electrolytes (SSEs) the recent research on quasi-solid-state battery (QSSB) approaches to overcome the issues of the state-of-the-art SSBs is reported. The feasibility of ionic liquid (IL)-based interlayers to improve ISE/Li metal wetting and enhance charge transfer at solid electrolyte interfaces with both positive and lithium metal electrodes is presented together with a novel generation of IL-containing quasi-solid-state-electrolytes (QSSEs), offering favourable features. The opportunities and challenges of QSSE for the development of high energy and high safety quasi-solid-state lithium metal batteries (QSSLMBs) are also discussed.

Optimization of polymer blend electrolytes with tuneable conductivity potentials

The potential of electrolytes' performance in electrochemical devices is among the leading research. There are several ways to improve the conductivity of electrolytes, including the employment of additive materials and polymer blends. This research aims to improve the conductivity of a polymer blend with quasi solid state electrolyte. Poly-methyl methacrylate (PMMA) and poly-vinylidene fluoride (PVdF) possed great electrochemical stability and thermal stability. Hence, these materials were chosen as the target polymer for the synthesis of the polymer blend. The electrical impedance spectroscopy (EIS) analysis showed an optimum conductivity value of 3.44 × 10−6 Scm−1 with the ratio of PMMA: PVdF (70:30) at ambient temperature. The dependent temperature of PBE was also analyzed to prove that the conductivity increases with the increment of temperature and low activation energy (Ea). The thermogravimetric analysis (TGA) shows the stability of PBE up to 651 °C. Through this research, there are several different concentrations of PBE to investigate the stability of PBE with great value in the conductivity performance.