The application of solid polymer electrolytes (SPEs) is still inherently limited by the unstable lithium (Li)/electrolyte interface, despite the advantages of security, flexibility, and workability ...of SPEs. Herein, the Li/electrolyte interface is modified by introducing Li2S additive to harvest stable all‐solid‐state lithium metal batteries (LMBs). Cryo‐transmission electron microscopy (cryo‐TEM) results demonstrate a mosaic interface between poly(ethylene oxide) (PEO) electrolytes and Li metal anodes, in which abundant crystalline grains of Li, Li2O, LiOH, and Li2CO3 are randomly distributed. Besides, cryo‐TEM visualization, combined with molecular dynamics simulations, reveals that the introduction of Li2S accelerates the decomposition of N(CF3SO2)2− and consequently promotes the formation of abundant LiF nanocrystals in the Li/PEO interface. The generated LiF is further verified to inhibit the breakage of CO bonds in the polymer chains and prevents the continuous interface reaction between Li and PEO. Therefore, the all‐solid‐state LMBs with the LiF‐enriched interface exhibit improved cycling capability and stability in a cell configuration with an ultralong lifespan over 1800 h. This work is believed to open up a new avenue for rational design of high‐performance all‐solid‐state LMBs.
Based on the atomic visualization of the lithium (Li)/poly(ethylene oxide) (PEO) interface through cryo‐transmission electron microscopy, Li2S additive is revealed to promote the decomposition of LiN(CF3SO2)2 (LiTFSI) to generate uniform LiF nanocrystals in situ, rendering uniform Li deposition and preventing PEO bond cleavage. This optimized interface is promising for PEO‐electrolyte‐based Li metal batteries with significantly improved cycling lifespan.
An enabling composite electrolyteLithium-air batteries have scope to compete with gasoline in terms of energy density. However, in most systems, the reaction pathways either involve one- or ...two-electron transfer, leading to lithium peroxide (Li2O2) or lithium superoxide (LiO2), respectively. Kondori et al. investigated a lithium-air battery that uses a ceramic-polyethylene oxide–based composite solid electrolyte and found that it can undergo a four-electron redox reaction through lithium oxide (Li2O) formation and decomposition (see the Perspective by Dong and Lu). The composite electrolyte embedded with Li10GeP2S12 nanoparticles shows high ionic conductivity and stability and high cycle stability through a four-electron transfer process. —MSL
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•High performance PEO/Na3Zr2Si2PO12 electrolyte films were prepared.•Na3Zr2Si2PO12 based electrolytes possess excellent thermal stability.•Succinonitrile build better sodium ions ...transfer channels in cathode.•All-solid-state Na batteries exhibit excellent electrochemical performance.
Solid electrolytes with satisfactory ionic conductivity, good flexibility, and ideal interface compatibility are the key to developing next-generation solid-state rechargeable sodium metal batteries. Herein, nano-sized NASICON-type Na3Zr2Si2PO12 (NZSP) powders were firstly prepared by sol–gel method. After that, two kinds of high-performance polyethylene oxide/NZSP composite solid electrolytes were fabricated by solution-casting method, which exhibit high ionic conductivities (>10−4 S cm−1 at 55 °C), wide electrochemical window (>4.7 V vs. Na+/Na), and good capability to impede sodium dendrites. In order to build better transfer channels for sodium ions in cathode and relieve the volume change of cathode particles during cycling, succinonitrile interphase was introduced by a simple dispersing method. The all-solid-state Na0.67Ni0.33Mn0.67O2|Na batteries based on the two kinds of electrolytes both exhibit excellent electrochemical performances with high discharge capacity of 73.2 mA h g−1 (68.2 mA h g−1) and high capacity retention of 98.4% (97.6%) after 100 cycles at 0.5C and 55 °C. These results promise a splendid strategy for designing high performance all-solid-state sodium batteries.
Li10GeP2S12 (LGPS) is incorporated into polyethylene oxide (PEO) matrix to fabricate composite solid polymer electrolyte (SPE) membranes. The lithium ion conductivities of as-prepared composite ...membranes are evaluated, and the optimal composite membrane exhibits a maximum ionic conductivity of 1.21 × 10−3 S cm−1 at 80 °C and an electrochemical window of 0–5.7 V. The phase transition behaviors for electrolytes are characterized by DSC, and the possible reasons for their enhanced ionic conductivities are discussed. The LGPS microparticles, acting as active fillers incorporation into the PEO matrix, have a positive effect on the ionic conductivity, lithium ion transference number and electrochemical stabilities. In addition, two kinds of all-solid-state lithium batteries (LiFeO4/SPE/Li and LiCoO2/SPE/Li) are fabricated to demonstrate the good compatibility between this new SPE membrane and different electrodes. And the LiFePO4/Li battery exhibits fascinating electrochemical performance with high capacity retention (92.5% after 50 cycles at 60 °C) and attractive capacities of 158, 148, 138 and 99 mAh g−1 at current rates of 0.1 C, 0.2 C, 0.5 C and 1 C at 60 °C, respectively. It is demonstrated that this new composite SPE should be a promising electrolyte applied in solid state batteries based on lithium metal electrode.
•Li10GeP2S12 was selected to disperse into PEO-based polymer to prepare a new SPE.•The ionic conductivity and electrochemical stability of new SPE electrolyte is improved.•The electrochemical window of new SPE is broadened.•The LiFePO4/Li battery fabricated with this new SPE exhibited excellent performance.
The advent of solid‐state polymer electrolytes for application in lithium batteries took place more than four decades ago when the ability of polyethylene oxide (PEO) to dissolve suitable lithium ...salts was demonstrated. Since then, many modifications of this basic system have been proposed and tested, involving the addition of conventional, carbonate‐based electrolytes, low molecular weight polymers, ceramic fillers, and others. This Review focuses on ternary polymer electrolytes, that is, ion‐conducting systems consisting of a polymer incorporating two salts, one bearing the lithium cation and the other introducing additional anions capable of plasticizing the polymer chains. Assessing the state of the research field of solid‐state, ternary polymer electrolytes, while giving background on the whole field of polymer electrolytes, this Review is expected to stimulate new thoughts and ideas on the challenges and opportunities of lithium‐metal batteries.
Safety net: Polymer electrolytes are a safe alternative to conventional liquid electrolytes in lithium batteries. Their main drawback is low ionic conductivity at room temperature. The most promising solution for this issue is incorporation of ionic liquids, which enhance the performance without decline in safety. This Review elucidates the interactions in these ternary polymer electrolytes and their performance in lithium‐metal polymer batteries.
A novel single lithium‐ion (Li‐ion) conducting polymer electrolyte is presented that is composed of the lithium salt of a polyanion, ...poly(4‐styrenesulfonyl)(trifluoromethyl(S‐trifluoromethylsulfonylimino)sulfonyl)imide (PSsTFSI−), and high‐molecular‐weight poly(ethylene oxide) (PEO). The neat LiPSsTFSI ionomer displays a low glass‐transition temperature (44.3 °C; that is, strongly plasticizing effect). The complex of LiPSsTFSI/PEO exhibits a high Li‐ion transference number (tLi+=0.91) and is thermally stable up to 300 °C. Meanwhile, it exhibits a Li‐ion conductivity as high as 1.35×10−4 S cm−1 at 90 °C, which is comparable to that for the classic ambipolar LiTFSI/PEO SPEs at the same temperature. These outstanding properties of the LiPSsTFSI/PEO blended polymer electrolyte would make it promising as solid polymer electrolytes for Li batteries.
A super‐delocalized polyanion is used for a single lithium‐ion conducting polymer electrolyte. The neat LiPSsTFSI ionomer displays a low glass‐transition temperature (44.3 °C), and its blended polymer electrolyte of the LiPSsTFSI/PEO exhibits a high Li‐ion transference number (tLi+=0.91) and high ionic conductivities of individual Li+ cations, which are comparable to those for the classic ambipolar LiTFSI/PEO SPEs above 70 °C (the melting point).
Background: Wounds are one of the most crucial health issues, especially when they are infected with pathogenic microbes. Nowadays, nanofibers have been designed with antibacterial properties to ...serve as an effective solution for wound healing. Materials and Methods: In this research, a polyethylene oxide/copper/peptide nanocomposite was designed using electrospinning at a ratio of 98/1/1 mg. Then, the characteristics of the nanocomposite were analyzed by scanning electron microscopy (SEM), tensile testing and differential scanning calorimetry (DSC). In addition, the antibacterial properties of the prepared nanofibers were evaluated against standard strains of Staphylococcus aureus and Escherichia coli, and the antioxidant effects of the said composite were evaluated. Results: The SEM results showed that copper and peptide nanoparticles were well spread on the surface of the polymer and the tensile test results revealed that this sample has relatively high tensile strength. Also, the designed nanocomposite was resistant to heat according to the DSC and had antibacterial effects against standard microbial strains and antioxidant properties. Conclusion: The results of this study showed that the designed nanofibers can be used as a compound with antimicrobial and antioxidant properties in the healthcare and hygiene industries to produce wound dressings.
Reported here is the first aqueous ring‐opening polymerization (ROP) of N‐carboxyanhydrides (NCAs) using α‐amino‐poly(ethylene oxide) as a macroinitiator to protect the NCA monomers from hydrolysis ...through spontaneous in situ self‐assembly (ISA). This ROPISA process affords well‐defined amphiphilic diblock copolymers that simultaneously form original needle‐like nanoparticles.
Sharp as a needle: Reported here is the first aqueous ring‐opening polymerization (ROP) of carboxyanhydrides (NCAs) using α‐amino‐poly(ethylene oxide) as the macroinitiator to protect NCA monomers from hydrolysis through spontaneous in situ self‐assembly (ISA). This ROPISA process affords well‐defined amphiphilic diblock copolymers that simultaneously form needle‐like nanoparticles.
Zn dendrites growth and poor cycling stability are significant challenges for rechargeable aqueous Zn batteries. Zn metal deposition‐dissolution in aqueous electrolytes is typically determined by Zn ...anode–electrolyte interfaces. In this work, the role of a long‐chain polyethylene oxide (PEO) polymer as a multifunctional electrolyte additive in stabilizing Zn metal anodes is reported. PEO molecules suppress Zn2+ ion transfer kinetics and regulate Zn2+ ion concentration in the vicinity of Zn anodes through interactions between ether groups of PEO and Zn2+ ions. The suppressed Zn2+ ion transfer kinetics and homogeneous Zn2+ ion distribution at the interface promotes dendrite‐free homogeneous Zn deposition. In addition, electrochemically inert PEO molecules adsorbed onto Zn anodes can protect the anode surfaces from H2 generation and, thereby, enhance their electrochemical stability. Stable cycling over 3000 h and high reversibility (Coulombic efficiency > 99.5%) of Zn anodes is demonstrated in 1 m ZnSO4 electrolyte with 0.5 wt% PEO. This finding provides helpful insights into the mechanism of Zn metal anodes stabilization by low‐cost multifunctional polymer electrolyte additives that stabilize interfacial reactions.
A long‐chain polyethylene oxide (PEO) polymer is developed as an effective multifunctional electrolyte additive to effectively suppress Zn2+ ion transfer kinetics, smooth Zn2+ ion distribution, prevent gas generation, enabling stable Zn deposition. Stable cycling over 3000 h and high reversibility (Coulombic efficiency > 99.5%) of Zn anodes are demonstrated with PEO additives in 1 m ZnSO4 aqueous electrolytes.
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