Composite polyethylene-oxide/garnet electrolytes containing LiTFSI as the lithium salt have a Li+ conductivity σLi > 10−4Scm−1 at 55°C and a low plating/stripping impedance of a dendrite-free ...Li-metal anode; they have been developed for a safe solid-state Li-metal rechargeable battery. Composites consisting of “ceramic-in-polymer” to “polymer-in-ceramic” that are flexible and mechanically robust are fabricated by hot-pressing. Safe pouch cells with a remarkable flexibility have been fabricated. Solid-state LiFePO4|Li batteries with electrolytes of “ceramic-in-polymer” and “polymer-in-ceramic” deliver excellent cycling stability with high discharge capacities (139.1mAhg–1 with capacity retention of 93.6% after 100 cycles) and high capacity retention (103.6% with coulombic efficiency of 100% after 50 cycles) at 0.2C and 55°C. Both kinds of electrolytes can be applied to solid-state lithium batteries.
PEO/garnet composite electrolytes from “ceramic-in-polymer” to “polymer-in-ceramic” are prepared by hot-pressing technology without introducing any solvent. The resultant electrolytes exhibit excellent electrochemical properties and the assembled batteries deliver high cycling stability and stable interface with Li anode, demonstrating a promising strategy for a safe, high-performance and solid-state Lithium batteries. Display omitted
•PEO/garnet electrolyte has a Li+ conductivity σLi > 10−4Scm−1 at 55°C.•The electrolytes are flexible and mechanically robust.•The membrane has a low plating/stripping impedance.•All-solid-state LiFePO4/Li cell has a discharge capacities of 148.6mAhg−1.
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•PI Framework is introduced to reinforce the mechanical strength of PEO CPEs.•SN increases the ionic conductivity of PEO CPEs to 1.03 × 10−4 S cm−1 at 30 °C.•PI and SN synergistic ...effects of enhance Li dendrite blocking ability of PEO CPEs.•LiFePO4/PI-PEO-SN/Li battery exhibits long cycling lifespan and high safety.
The replacement of traditional liquid electrolytes with polyethylene oxide (PEO) based composite polymer electrolytes (CPEs) is an important strategy to address the current flammability and explosiveness of lithium batteries since PEO CPEs have high flexibility, excellent processability and moderate cost. However, the insufficient ionic conductivity and inferior mechanical strength of PEO CPEs do not suit the operating requirements of all-solid-state lithium metal batteries at room temperature. Herein, three-dimensional (3D) framework composed of interweaved high-modulus polyimide (PI) nanofibers along with functional succinonitrile (SN) plasticizers are employed to synergistically reinforce the ionic conductivity and mechanical strength of PEO CPEs. Impressively, benefitting from the synergistic effects of 3D PI framework and SN plasticizer, PI-PEO-SN CPEs exhibits high ionic conductivity of 1.03 × 10−4 S cm−1 at 30 °C, remarkable tensile strength of 4.52 MPa, and superior Li dendrites blocking ability (>400 h at 0.1 mA cm−2). Such favorable features of PI-PEO-SN CPEs endow LiFePO4/PI-PEO-SN/Li solid-state prototype cells with high specific capacity (151.2 mA h g−1 at 0.2 C), long cycling lifespan (>150 cycles with 91.7 % capacity retention), and superior operating safety even under bending, folding and cutting harsh conditions. This work will pave the avenues to design and fabricate new high-performance PEO CPEs for the high energy density and safety all-solid-state batteries.
The advantages of all-solid-state batteries in terms of high energy density and improved safety have accelerated the research into durable and reliable solid electrolytes and into scale up of their ...processing technology. High lithium-ion-conducting Li7La3Zr2O12 (LLZO) ceramic-based solid electrolytes have been intensively studied recently, but their widespread commercial deployment has been constrained due to their fragility and brittleness. In the present study, LLZO ceramic powders have been successfully incorporated into the polyethylene oxide (PEO) polymer by tape casting. The ionic conductivity of the PEO/LLZO composite electrolyte membranes is significantly enhanced at the optimal LLZO concentration of 7.5 wt.% at which the materials exhibits maximum ionic conductivity of 5.5 × 10−4 S·cm−1 at 30 °C. The ionic conductivity enhancement mechanism of the composite electrolyte is revealed by differential scanning calorimetry (DSC), which shows that the LLZO filler represses crystallinity in PEO. Furthermore, as evidence of the advantageous electrochemical properties of the composite electrolyte an all-solid-state battery of LiFePO4/Li fabricated herein delivered a maximum discharge capacity of 150.1 mAh·g−1 at 0.1C, good cycling performance, and excellent rate capability under 60 °C.
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•High ionic conductive solid polymer electrolyte were synthesized by tape casting.•Cubic LLZO as ceramic filler into PEO have a synergetic effect on the Li ionic conductivity.•The electrochemical window and the interfacial behavior with lithium electrodes of solid electrolyte is improved.•The all-solid-state lithium battery Li/LiFePO4 exhibits fascinating cycling and rate performance.
•The amidoxime modified polymer of intrinsic microporosity (AOPIM-1) is designed as a filler.•The AOPIM-1 urges PEO electrolyte to get high mechanical strength.•A stable interface between electrode ...and electrolyte is obtained.•The LiFePO4/Li battery exhibits a long-term cycling stability.•The composite electrolyte can steadily recycle in high-voltage atmosphere.
Poly (ethylene oxide) (PEO)-based solid polymer electrolytes (SPEs) have attracted intensive attention in recent years due to the high salt solubility and flexibility in lithium-ion batteries (LIBs). However, the application of such solid electrolytes is severely limited owing to low ionic conductivity and poor mechanical strength. The integration of the amidoxime modified polymer of intrinsic microporosity (AOPIM-1) with PEO electrolyte is designed to attain a novel composite solid electrolyte (CPE). At an optimal doping amount of 1.5 %, the effects of AOPIM-1 on the physicochemical and electrochemical properties of CPE are investigated and discussed. Because of the electrostatic action between Li+ and polar amidoxime groups, more rapid Li+ transport could promote the electrochemical performances of CPE. The liquid-free CPE-1.5 % AOPIM-1 could show a satisfactory ionic conductivity (1.18 × 10−3 S cm−1 at 60 °C). The rigid skeleton of AOPIM-1 endows the high mechanical strength of CPE to inhibit the growth of lithium dendrites for favorable interfacial stability with lithium metal. The LiFePO4 batteries combined with CPE-1.5% AOPIM-1 can supply 78.4 % capacity retention after 750 cycles at 0.5 C and 88.7 % capacity retention after 200 cycles at 1.0 C (60 °C). The use of AOPIM-1 would raise the oxidation potential of CPE, exhibiting a superior cycling stability (77.8 % capacity retention after 200 cycles at 0.5 C) in high-voltage LiNi0.5Co0.2 Mn0.3O2 (NCM523)/Li cells. This research can provide novel insights to achieve the much enhanced performance of composite electrolytes.
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The integration of Li2S6 within a poly(ethylene oxide) (PEO)‐based polymer electrolyte is demonstrated to improve the polymer electrolyte's ionic conductivity because the strong interplay between ...O2−(PEO) and Li+ from Li2S6 reduces the crystalline volume within the PEO. The Li/electrolyte interface is stabilized by the in situ formation of an ultra‐thin Li2S/Li2S2 layer via the reaction between Li2S6 and lithium metal, which increases the ionic transport at the interface and suppresses lithium dendrite growth. A symmetric Li/Li cell with the Li2S6‐integrated composite electrolyte has excellent cyclability and a high critical current density of 0.9 mA cm−2 at 40 °C. Impressive electrochemical performance is demonstrated with all‐solid‐state Li/LiFePO4 and high‐voltage Li/LiNi0.8Mn0.1Co0.1O2 cells at 40 °C.
Li2S6 is used as an additive for a PEO‐LiTFSI polymer electrolyte and serves to improve the Li+‐ion conductivity of the electrolyte by reducing the crystalline volume in the PEO as well as aiding in the formation of a thin stable layer that stabilizes the interface with lithium metal. This leads to an impressive electrochemical performance at 40 °C in all‐solid‐state full cells with a lithium metal anode and an LiFePO4 or LiNi0.8Mn0.1Co0.1O2 cathode.
All-solid-state lithium batteries (ASSB) are emerging as an effective and promising alternative to current technologies that use organic liquid electrolytes. Its main proposition is to mitigate the ...safety and environmental issues caused by the leakages and explosions of conventional cells through the development and use of solid electrolytes, in the form of polymer membranes, ceramic pellets, or even composites, which are a combination of both. In the present work, composite electrolytes of polyethylene oxide (PEO), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), and Zr-doped niobium garnet oxides (Li5+xLa3Nb2-xZrxO12 - LLNZ) were prepared. The addition of ceramic reduced the melting point and inhibited the formation of spherulite-type crystallization of the polymer. The ionic conductivities of the composites were slightly lower than the polymer but still high for composite electrolytes of this composition, around 10−4 S.cm−1. The obtained results were analyzed considering the findings reported by other researchers, and some factors for a high-performance composite electrolyte were detailed. Additionally, all the fabricated composites showed a broad electrochemical window, some even above 5.0 V. Thus, electrochemical measurements were conducted with NMC811 as the cathode. The half-cell exhibited a specific capacity of 185 mAh.g−1 at C/20 at 60 °C, and a capacity retention of 68% after 50 cycles at C/5. The results are promising and indicate the possibility of the use of high‑nickel cathodes in all-solid-state batteries to increase their energy density.
Schematic representation of the lithium ions transport in solid composite electrolytes with different ceramic loadings. Display omitted
•Solid composite electrolytes were prepared with PEO, LITFSI, and a Zr-doped Garnet.•All composites exhibited high ionic conductivities of ∼10−4 S/cm at 60 °C.•Electrochemical stability window above 5.0 V was observed for some samples.•Half-cell tests with NMC811 cathode resulted in 185 mAh.g−1 at 60 °C for C/20.
Constructing a solid electrolyte interface (SEI) is a highly effective approach to overcome the poor reversibility of lithium (Li) metal anodes. Herein, an adhesive and self‐healable supramolecular ...copolymer, comprising of pendant poly(ethylene oxide) (PEO) segments and ureido‐pyrimidinone (UPy) quadruple‐hydrogen‐bonding moieties, is developed as a protection layer of Li anode by a simple drop‐coating. The protection performance of in‐situ‐formed LiPEO–UPy SEI layer is significantly enhanced owing to the strong binding and improved stability arising from a spontaneous reaction between UPy groups and Li metal. An ultrathin (approximately 70 nm) LiPEO–UPy layer can contribute to stable and dendrite‐free cycling at a high areal capacity of 10 mAh cm−2 at 5 mA cm−2 for 1000 h. This coating together with the promising electrochemical performance offers a new strategy for the development of dendrite‐free metal anodes.
Stick with it: An adhesive and self‐healable supramolecular copolymer, comprising of pendant poly(ethylene oxide) segments and ureido‐pyrimidinone (Upy) hydrogen‐bonding moieties, has been developed and employed as a protection layer of a Li anode. This layer is self‐stabilizing because of a spontaneous reaction between the UPy groups and Li, enabling dendrite‐free cycling at a high areal capacity and current density.
Octylphenol polyethoxylates (OPEOn) are composed of a hydrophobic octylphenol (OP) group and a hydrophilic polyethylene oxide (EO) chain and are widely used in commercial products. Shorter EO chains ...and OPEOn biometabolites have been identified as endocrine-disrupting contaminants and can threaten biotic factors in the ecosystem. In this study, OPEOn at three EO lengths (TX-45, TX-114, and TX-165) were selected in monomer (MN) or micelle (MC) state for batch experiments under aerobic conditions, with results showing biodegradation rates of 90 % within 35–70 h. The pseudo-first-order constant (k) of OPEOn biodegradation was observed in the order TX-45 (0.1414 h−1) > TX-114 (0.0556 h−1) > TX-165 (0.0485 h−1), with biomineralisation reaching at least 80 % for all OPEOn. The selective biodegradation of EO chains was also measured, with initial accumulation of OPEO3 observed along with the depletion of longer EO chains for TX-45 and TX-114 in both the MN and MC states. A similar trend was observed for the MN state of TX-165, with OPEO3-OPEO9 observed to accumulate and reduced after 70 h. MC biodegradation was accomplished via the initial accumulation of OPEO3-OPEO9. The amounts of OPEO3 increased and others reduced; however, OPEO3 remained high at the end of biodegradation for TX-165. Bacterial community analysis indicated that the genera Sphingobium spp., Pseudomonas spp., Flavobacterium spp., Comamonas spp., and Sphingopyxis spp. dominate OPEOn biodegradation, and they have their roles during biodegradation, and the community-level physiological profile (CLPP) was also changed by biodegradation in both the MN and MC states.
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•Selective biodegradation: short OPEOn accumulation and long OPEOn depletion.•OPEOn length and structures influence biodegradation.•Pseudomonas, Sphingobium and Flavobacterium spp. were dominant during degradation.•Bacterial physiological traits changed before and after biodegradation.
Owing to high theoretical capacity, lithium-sulfur batteries (LSBs) are receiving extensive researches. However, cyclic instability and safety issues hugely confine the commercial applications of ...traditional liquid LSBs. In this work, for the sake of fully leveraging the high ionic conductivity of polyacrylonitrile while avoiding Li anode “passivation effect” caused by CN group, we prepare double-layer gel polymer electrolytes for quasi-solid-state LSBs. The transition layer composed of polyacrylonitrile, polyethylene oxide and Li1.3Al0.3Ti1.7(PO4)3 (LATP) is located on Li anode side to reduce “passivation effect” triggered by pure polyacrylonitrile. Meanwhile, the high ionic conductivity layer composed of polyacrylonitrile and LATP in contact with cathode can utilize the high intrinsic ionic conductivity of polyacrylonitrile to enhance the rate performance. Furthermore, LATP with higher ionic conductivity embedded in the membrane serves as Li+ transport channels to further increase ionic conductivity. Prominently, the designed double-layer electrolytes exhibit a high Li+ transference number of 0.55 and superior mechanical property. Moreover, stable coulombic efficiency of 99.6–100.0% over 100 cycles and good capacity retention of 79.0% after 100 cycles at 0.1C can be achieved. Our newly designed double-layer electrolytes with multiple functions exhibit potential applications in safer LSBs.
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•The HN hydrogen bond can weaken the “passivation effect” of cyano group.•Two layers in the electrolyte possess different electrochemical functions.•High ionic conductivity layer improves the ionic conductivity of the membrane.•Transition layer protects anode from passivation caused by pure polyacrylonitrile.
The present study reports the synthesis of composite films comprising PEO/Na2PtCl6 complex and their deposition onto fused silica substrates via the dip‐coating method. Chemical, crystallographic, ...and thermal characterizations are carried out to confirm the incorporation of Na2PtCl6 and PEO matrix into the films. The transmittance of the PEO film is initially high and decreases subsquently with an increase in Na2PtCl6 content. The optical band‐gap energy of the composite films decreases exponentially from 4.62 to 3.79 eV with the increase in Na2PtCl6 content. Furthermore, in the normal dispersion region, the refractive index of the PEO film decreases from 2.00 to 1.670 as the wavelength increases from 400 to 700 nm. The refractive index values increase with an increase in the concentration of Na2PtCl6 in the PEO film up to 8 wt.%. The incorporation of Na2PtCl6 into the PEO matrix increases the electrical conductivity because of the combined enhancement of the PEO conductivity and increase i Na2PtCl6. These findings suggest that PEO/Na2PtCl6 complex composite films have potential applications in UV‐shielding and optoelectronic devices.
