Solid-state lithium-ion batteries (SSLIBs) employing nickel-rich layered oxide cathodes are essential for electric vehicles and large-scale energy storage owing to their high energy density. Although solid polymer electrolytes are promising candidates for these systems, their practical deployment remains constrained by insufficient ionic conductivity, limited oxidative stability, and safety concerns arising from polymer membrane shrinkage under thermally abusive conditions. Herein, we report a highly safe organic-inorganic hybrid quasi-solid polymer electrolyte (HQSPE) based on a poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) host matrix plasticized with ethylene carbonate and reinforced with Al2O3 ceramic filler. The incorporation of Al2O3 induces polymer chain amorphization, enhances ionic conductivity, improves thermal stability, and establishes favorable Lewis acid-base interactions that effectively regulate anion mobility. Consequently, the optimized HQSPE exhibits a high ionic conductivity of 4.13 mS cm-1 at room temperature and an elevated Li+ transference number of 0.58. The electrolyte further demonstrates outstanding thermal robustness with minimal dimensional shrinkage at 200 °C and an expanded oxidative stability window approaching 4.99 V vs. Li/Li+. When assembled into high-loading Graphite-SiOx||LiNi0.8Co0.1Mn0.1O2 full cells, the HQSPE delivers superior rate capability and long-term cycling stability, retaining 81% of its initial capacity after 300 cycles at 0.5C with high Coulombic efficiency. These results establish a rational design strategy for hybrid quasi-solid polymer electrolytes that effectively balance ionic transport, interfacial stability, and thermal safety, offering a viable pathway toward practical high-energy lithium-ion batteries.

Silicon suboxide (SiOx) has emerged as a viable anode material for lithium-ion batteries (LIBs) because of its high theoretical specific capacity and structural stability. However, its practical application is restricted by inadequate cycling stability and poor electrical conductivity. Herein, plasma-enhanced chemical vapor deposition (PE-CVD) was utilized to synthesize SiOx-SPC composites, in which the optimized spherical porous CNTs (SPC) provided a well-defined porous framework that facilitated uniform SiOx deposition. The resulting SiOx-SPC composite (SSC) exhibits high electrical conductivity, Li-ion diffusivity, and mechanical stability, which remarkably enhance the cyclic stability and rate capability. As a result, the SSC electrode exhibits a high initial specific capacity of 1032.26 mAh g-1 and achieves exceptional cycling performance, considerably surpassing microsized SiOx (MSiOx) particles (∼102% vs ∼41% retention after 100 cycles at 0.5C). Moreover, SSC shows enhanced Li-ion diffusion (4.66 × 10-10 cm2 s-1) as evaluated by cyclic voltammetry. This work demonstrates the essential role of the SiOx coating on optimized SPC via PE-CVD and enables the development of long-lasting, high-capacity anode materials for advanced lithium-ion battery technologies.

The advancement of lithium metal batteries (LMBs) is crucial for next-generation high-energy storage systems, particularly for electric vehicles. However, their practical implementation is hindered by uncontrolled lithium dendrite growth, leading to capacity degradation and poor cycling stability. This study introduces a composite protective layer (CPL) composed of poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) and SiO2 particles to address these challenges. The CPL effectively suppresses dendrite formation and stabilizes the solidelectrolyte interphase, enhancing cycling stability and electrochemical performance. The optimized CPL exhibits excellent electrochemical stability within a 4.7 V potential window and a high lithium-ion transference number of 0.37. Symmetric CPL-coated lithium cells demonstrate stable plating-stripping behavior over 400 cycles at a current density of 2 mA cm-2 with a fixed areal capacity of 2 mAh cm-2. In a full-cell configuration with an NCM622 cathode, the CPL-coated lithium anode retains a reversible areal capacity of 3.08 mAh cm-2 over 450 cycles, achieving 90.9 % capacity retention and an average coulombic efficiency of 99.77 % at a 0.5C/1.0C charge-discharge rate. This organic-inorganic hybrid strategy provides a promising approach to mitigating key challenges of lithium metal anodes, extending battery lifespan, and enhancing safety for high-energy storage applications.

Lithium-air batteries (LABs) offer remarkable theoretical energy density but struggle with challenges like insulating Li2O2 discharge products, higher overpotentials, and unstable interfacial chemistries leading to shorter life cycles. In this study, hydroxy-TEMPO was incorporated as a redox mediator to enhance the reversibility of Li-O2 products. Incorporating hydroxy-TEMPO to a 1,2-dimethoxyethane electrolyte notably decreased overpotential to 1.03 V and increased areal capacity from 0.46 mAh cm- 2 (0 %) to 14.08 mAh cm- 2 (20 %), with maintained coulombic efficiency over 99 % for 400 cycles at 0.5 mAcm- 2. To mitigate parasitic reactions between Li and hydroxy-TEMPO, a protective layer, composed of PVDF-HFP, SiO2, and EC with LiPF6, was applied to Li-anode. SEM-EDX analysis revealed uniform elemental distribution and reduced incorporation of nitrogen contents from 8.96 wt% on bare Li to 5.20 wt% on coated Li, and sulfur contents from 14.72 wt% to 10.38 wt% after cycling, confirmed deceased decomposition of hydroxy-TEMPO and electrolyte while demonstrating its chemical stability for longer cycling. FTIR analysis exhibited lower intensities of vibrational bands for degradation products (C--O, CO32- ), revealing reduced electrolytic degradation and SEI thickness. XPS elemental survey demonstrated the retention of Si, P, and F species derived from protective layer, indicating reduced sulfonated and carbonaceous byproducts. All findings confirmed the synergistic role of hydroxy-TEMPO and protective layer in developing a compact, inorganic-rich SEI that enhances electrochemical stability of Li-anode, remarkably improves the cycling and efficiency, and enables stable performance under real-air conditions, thereby offering a promising approach for practical applications of LABs in energy storage systems.

The development of high-energy lithium-ion batteries (LIBs) with enhanced safety and durability requires overcoming challenges related to electrolyte instability, low ionic conductivity, and inadequate mechanical strength. This study introduces a composite quasi-solid polymer electrolyte (CQSPE) based on PVDF-HFP, optimized with Al2O3 nanoparticles to enhance fire retardancy, mechanical strength, ionic conductivity, and interfacial stability. The CQSPE containing 15 wt% Al2O3 exhibits a high ionic conductivity of 6.5 mS cm-1 at 60 degrees C and a tensile strength of 1.56 MPa, effectively suppressing dendrite formation during cycling. The influence of CQSPE thickness (30, 60, and 90 mu m) on electrochemical performance is systematically analyzed. The 60 mu m membrane demonstrates optimal performance, with superior plasticizer retention and balanced mechanical properties. In a full-cell configuration (Gr-SiOx|CQSPE|NCM622), the 60 mu m electrolyte delivers a reversible areal capacity of 2.61 mAh cm-2 with 72.96 % capacity retention after 300 cycles at 0.5C. Additionally, a double-layered pouch cell with this optimized CQSPE exhibits an initial discharge capacity of 1 Ah (2.76 mAh cm-2) and 79.6 % capacity retention over 350 cycles at 0.5C/1C. The facile structural design of CQSPE provides a promising pathway for the development of high-performance solid-state lithium-ion batteries in the near future.

In this study, one kilowatt aqueous redox flow battery (ARFB) using anthraquinone-2,7-disulfonic acid (2,7-AQDS) and vanadium oxide sulfate (VOSO4) as active materials for negalyte (negative electrolyte) and posilyte (positive electrolyte) is successfully accomplished. Then, manganese sulfate (MnSO4) is further included in negalyte to increase reactivity of active materials and to suppress their crossover by controlling their osmotic pressure. This binary effects of MnSO4 are predicted by density functional theory and reduction in concentration gap. The decrease in energy band gap of 2,7-AQDS with MnSO4 facilitated electron transfer rate. Anodic and cathodic diffusion coefficient and reaction rate constant are also improved. More specifically, with adoption of MnSO4 additive, energy efficiency and capacity retention rate of ARFB single cells operated with MnSO4 additive are improved from 79.1 to 83.9% at the current density of 40 mA cm-2 and from 82 to 88% at the current density of 80 mA cm-2 after 100 cycles. Based on that, ARFB stack using 2,7-AQDS and VOSO4 with MnSO4 additive is prepared and this ARFB stack exhibits a high power of 1.15 kW.

Although vanadium redox flow batteries hold great promise for energy storage systems, Nafion (being a conventional membrane material) requires improvement in terms of the crossover phenomenon. Herein, a nanoporous metal-organic framework (MOF) is applied as a membrane for vanadium redox flow batteries via addition of the MOF to a Nafion solution to prepare Nafion/MOF composite membranes via casting. Composite membranes are fabricated into a Nafion matrix by introducing small amounts of CAU-10-X (X = -OH, -CH3, -OS1, -OS2), an Al-based MOF synthesized with ligands having hydroxyl, methyl, and a combination of hydroxyl and sulfonic acid functional groups. The membrane physicochemical properties (such as water uptake, swelling ratio, ion exchange capacity, proton conductivity, and electrochemical properties from charge-discharge experiments on a single cell) are compared and evaluated. In 100 charge-discharge cycles of the single cell at a current density of 160 mA cm-2, the composite membrane N/CAU-10-OS1 with 0.6 wt% dispersed MOF and a combination of hydroxyl and sulfonic acid functional groups exhibits capacity retention of 80.34% and energy efficiency of 77.56% at approximately 50 mu m thickness. These values are better those achieved by commercial separation membrane Nafion 115 with 127 mu m thickness tested under identical conditions and the proposed membrane is thus expected to be economically advantageous.

The high price of metal-based electrolyte is delaying commercialization of the metal-based redox flow battery (RFB). Instead, the alkaline-based organic redox flow battery (AORFB) using synthetic active compounds, e.g., alloxazine 7/8-carboxylic acid (ACA), is attracting attention as a promising alternative. However, the working principle of the AORFBs is still unclear. This study aims to theoretically elucidate the working mechanism of the ACA-based AORFB by, for the first time, taking a computational approach. First, experimentally determined kinetic parameters were used to construct a transient, multi-dimensional model. Then, the developed computational model of the AORFB was used to investigate the effects of operating conditions. The results showed that the negative activation overpotential is less than 50.0% of positive side. The ionic conductivities of negative and positive electrolyte were estimated in a range of (51.2 to 69.2) S m(-1) and (45.7 to 53.2) S m(-1), respectively. Further, at low positive flowrate (15 mL min(-1)), the [Fe(CN)(6)](4-) concentration decreased from (250 to 16.39) mol m(-3), which caused a large potential loss. Finally, it was found that diffusion and electro-osmosis drag dominated water permeation through the membrane in the AORFB.

Enhancing the effective electronic transportation pathways and high loading mass of cathode are the challenges for high energy density solid-state batteries. We successfully enhanced significantly the electrochemical characteristics of all-solid-state Li-ion battery (ASSLIB) composed of graphite/SiOx anode, PVDF-HFP/Al2O3 based composite solid polymer electrolyte (CSPE), and LiNi0.6CO0.2Mn0.2O2 cathode with high proportion of 96.94 wt% in cathode by employing only small amount (0.06 wt%) of SWCNT in electrodes. The Li/CSPE/NCM@CNT cell maintained a capacity of 2.31 mAh cm(-2) at rate of 0.5C with a capacity retention of similar to 93% over 50 cycles. Moreover, The Li/CSPE/G-SiOx@CNT cell delivered an areal charge capacity of 3.7 mAh cm(-2) at a rate of 0.5C. Furthermore, the ASSLIBs with a high cathode mass loading of 36.4 mg cm(-2) delivered a high areal capacity of 4.04 mAh cm(-2) and successfully operated for longer than 300 cycles at rate of 0.5C. The ASSLIBs show excellent cyclability with capacity retention of similar to 80% and coulombic efficiency of approximately 100%, even at a considerably high cathode mass loading of 36.4 mg cm(-2) at a rate of 0.5C. The SWCNT form a conductive network throughout the electrodes by providing prolonged electron transport pathways and enhance the overall electrochemical properties of ASSLIBs.

Solid electrolytes are a potential candidate for mitigating the safety issues associated with organic liquid-electrolyte-based conventional Lithium-Ion Batteries (LIBs). The film-forming ability, cost-effective fabrication, and superior interfacial contact of solid polymer electrolytes make them particularly appealing for application in all-solid-state LIBs (ASSLIBs). However, their practical applications are limited owing to their low lithium-ion conductivity and inadequate mechanical strength. In this study, we fabricated a highly flexible, soft, self-standing, and stable composite solid polymer electrolyte (CSPE) using poly(propylene carbonate) (PPC) as the main matrix and Na-superionic-conductor-type Li1.5Al0.5Ge1.5(PO4)(3) (LAGP) as the active inorganic filler. The fabricated CSPE exhibited an attractive ionic conductivity of similar to 0.56 mS.cm(-1), a wide electrochemical potential stability of similar to 5 V vs. Li/Li+, a high lithium-ion transference number of similar to 0.77, outstanding stability up to 1000 cycles of lithium plating/stripping, and better compatibility with lithium metal. In addition to these outstanding properties, the Li/CSPE/LiFePO4 (Li/CSPE/LFP) cell exhibited an impressive discharge capacity of 151 mAh.g(-1) at 0.1 C. Furthermore, at a rate of 1 C, the Li/CSPE/LFP cell delivered an initial discharge capacity of 96 mAh.g(-1), with a capacity retention of 63% over 1000 cycles. The interaction of lithium ions with the PPC was confirmed based on solid-state MAS NMR and XPS. The enhanced electrochemical performance of the CSPE is ascribed to the interaction of the LAGP filler with the PPC matrix, which forms a good polymer-inorganic interface, enabling the rapid lithium-ion transport. The proposed LAGP-reinforced CSPE presents new opportunities for the fabrication and engineering of ASSLIBs. (C) 2021 Elsevier Ltd. All rights reserved.

Composite solid polymer electrolytes (CSPEs) are promising candidates for replacing potentially hazardous organic liquid electrolytes used in Li ion batteries (LIBs). CSPEs are easy to process, have the ability to form films, and make better interfacial contact. However, their poor mechanical strength, low ionic conductivity, and long cycling stability limit their practical applications. Here, we demonstrate the fabrication of a cost-effective, flexible, self-standing, and highly stable CSPE using poly(propylene carbonate) (PPC) as the host matrix and highly mesoporous silica nanoparticles (MSNs) as the filler. The fabricated CSPE had a high ionic conductivity of approximately 8.5 x 10(-4) S cm(-1) at 60 degrees C, electrochemical potential stability up to approximately 4.8 V vs. Li/Li+, an ultra-high lithium transference number of approximately 0.86, impressive stability over 1000 h of Li stripping/plating, and an excellent electrode compatibility. With cyclability over 200 cycles and a negligible overpotential, the Li/CSPE/LFP cell delivered a reversible capacity of 171 and 103 mAh g(-1) at 0.1 C and 1 C, respectively, with a good rate capability up to 5 C. The interaction of Li+ with PPC and the MSNs is demonstrated by solid-state magic angle spinning nuclear magnetic resonance (MAS-NMR) and X-ray photoelectron spectroscopy (XPS) studies. The enhanced physico-electrochemical properties of the CSPE were attributed to the large MSNs-related surface area, which enables firm interaction with the PPC matrix and provides a less-tortuous polymer-ceramic phase for fast lithium ion transportation. The proposed MSNs-reinforced CSPE thus opens new possibilities for the fabrication and engineering of solid-state batteries.

In this article, we report the effect of using nanoparticles for LiMn2O4 cathode materials in flexible batteries with organic–inorganic hybrid electrolytes. LiMn2O4 nanoparticles for the cathode are prepared by pyro-synthesis. Electrochemical measurement indicated the discharge capacities were 118.41 and 138.12mAhg−1 and the coulombic efficiencies were 91.50% and 97.28% for the micro- and nano-LMO materials, respectively. This is attributed to the nano-LiMn2O4 material having particle sizes in the nanoscale dimension, and shorter diffusion paths combined with a large contact area at the electrode/electrolyte interface. Furthermore, the pouch-type cells demonstrated similar properties, with initial discharge capacities of 85.63 and 99.96mAhg−1 and coulomb efficiencies of 79.27% and 90.27% for the micro- and nano-LMO cells, respectively. Nanoparticles allow Li+ ions to de-intercalate and intercalate very easily because of the very short lithium diffusion distance.

We have synthesized a self-standing, flexible, highly ion conductive, and electrochemically stable composite solid polymer electrolyte (CSPE) composed of a poly(ethylene oxide) matrix, Li7La3Zr2O12 ceramic filler, and poly (ethylene glycol) dimethyl ether (PEGDME) plasticizer for all-solid-state Li-ion batteries. The CSPE containing 10 wt% PEGDME (CSPE10) shows the highest ionic conductivity of 4.7 x 10(-4) S cm(-1) at 60 degrees C. Additionally, all the CSPEs are stable up to 5.0 V vs. Li/Li+, and CSPE10 shows a high Li-ion transference number of 0.48 at 60 degrees C. When Li/CSPE/Li symmetric cells are cyclically polarized, the cell with CSPE10 shows the smallest overpotential because of the high ionic conductivity of CSPE10 and the low interfacial resistance between Li and CSPE10. The all-solid-state full cell with the Li/CSPE10/LiNi0.6Co0.2Mn0.2O2 configuration delivers an initial discharge capacity of 157 mA h g(-1) at 0.1C at 60 degrees C. Even after 100 cycles at a higher C-rate of 0.5C, the full cell maintains high discharge capacity of 116 mA h g(-1) corresponding to a capacity retention of similar to 86%. The full cell with a high LiNi0.6Co0.2Mn0.2O2 mass loading of 7.7 mg cm(-2) shows an initial discharge capacity of similar to 160 mA h g(-1) and maintains high discharge capacity of 140 mA h g(-1) even after 60 cycles.

Li7La3Zr2O12 powders with cubic phase and high ionic conductivity were synthesized using co-precipitation process, in which the mixture precursors of La-Zr-(OH)(x) and Li source were calcined and sintered at different conditions. XRD analysis showed that cubic phase of garnet-type LLZO powder is formed as calcined at 700 and 800 degrees C, respectively. However, tetragonal phase is formed at above 900 degrees C. As these samples were sintered in the form of pellets at 1200 degrees C, LLZO powder calcined at 700 degrees C showed excellent ionic conductivity of 3.2 x 10(-4) S cm(-1) at 25 degrees C, indicating cubic structure of LLZO single phase and high relative density of above 90% that is different with LLZO powder calcined at 900 degrees C. (C) 2016 Published by Elsevier B.V. on behalf of The Korean Society of Industrial and Engineering Chemistry.

Electro-spun nanofiber web is highly attractive as a separator for lithium ion batteries because of its high electrical properties. In moving toward wider battery applications of the nanofiber separators, a deeper understanding on the structure and property relationship is highly meaningful. In this regard, we prepared electro-spun poly(vinylidene fluoride) (PVdF) webs with various thicknesses (10.5~100 µm) and investigated their structures and electrochemical performances. As the thickness of the web is decreased, a decrease of porosity and an increase of pore size are resulted in. For the 10.5 µm-thick separator, a minor short-circuit was detected, stressing the importance of reducing pore-size on prevention of short-circuit. However, above the thickness of 21 µm, well-connected, submicron-sized pores are generated, and, with lowering the separator thickness, discharge capacity and rate capability are enhanced owing to the lowered area-specific resistance.

With an aim to enhance the thermal stability and electrolyte wetting of a polyethylene porous separator, an Al2O3 nano-powder layer and an electro-spun PVdF nanofiber layer were successively formed on both sides of the polyethylene separator. The Al2O3 layer provides excellent thermal stability as indicated by thermal shrinkage of only 7.8 % in area at 180 °C and absence of a meltdown up to 200 °C. The electrolyte uptake of the multilayer separator was increased with the thickness of the nanofiber layer. As a result, discharge capacity, rate capability, and cycle life of the lithium ion batteries employing the PVdF nanofiber layers were improved, overcompensating for a loss of performance caused by the Al2O3 layer. Therefore, the multilayer approach is highly effective in improving both the performance and safety of lithium ion batteries.