Polyether electrolytes have been widely recognized for their favorable compatibility with lithium-metal, yet they are hampered by intrinsically low oxidation thresholds, limiting their potential for realizing high-energy Li-metal batteries. Here, we report a general approach involving the bridge joints between non-lithium metal ions and ethereal oxygen, which significantly enhances the oxidation stability of various polyether electrolyte systems. To demonstrate the feasibility of the ion-bridging strategy, a Zn2+ ion-bridged polyether electrolyte (Zn-IBPE) with an extending electrochemical stability window of over 5 V is prepared, which enables good cyclability in 4.5 V Li||LiCoO2 batteries. Ampere-hour-level quasi-solid-state batteries of SiO-graphite||LiNi0.8Mn0.1Co0.1O2 (10 Ah, N/P ratio of 1.12, 303 Wh kg-1 at 0.1 C based on the total weight of the pouch cells) and 60 mu m-Li||LiNi0.9Mn0.05Co0.05O2 (18 Ah, N/P ratio of 2.5, 452 Wh kg-1 at 0.33 C based on the total weight of the pouch cells) pouch cells with Zn-IBPE present elevated electrochemical performance, benefiting from adequate interfacial stability. Nail penetration tests evidence high battery safety enabled by Zn-IBPE in 4 Ah graphite||LiNi0.8Mn0.1Co0.1O2 pouch cells without combustion or smoke. This work offers a pathway for designing high-voltage polymer electrolytes and a general solution for achieving high-performance quasi-solid-state batteries.

Superionic halides have attracted widespread attention as solid electrolytes due to their excellent ionic conductivity, soft texture, and stability toward high-voltage electrode materials. Among them, Li3InCl6 has aroused interest since it can be easily synthesized in water or ethanol. However, investigations into the influence of solvents on both the crystal structure and properties remain unexplored. In this work, Li3InCl6 is synthesized by three different solvents: water, ethanol, and water-ethanol mixture, and the difference in properties has been studied. The results show that the product obtained by the ethanol solvent demonstrates the largest unit cell parameters with more vacancies, which tend to crystallize on the (131) plane and provide the 3D isotropic network migration for lithium-ions. Thus, it exhibits the highest ionic conductivity (1.06 mS cm-1) at room temperature and the lowest binding energy (0.272 eV). The assembled all-solid-state lithium metal batteries (ASSLMBs) employing Li3InCl6 electrolytes demonstrate a high initial discharge capacity of 153.9 mA h g-1 at 0.1 C (1 C = 170 mA h g-1) and the reversible capacity retention rate can reach 82.83% after 50 cycles. This work studies the difference in ionic conductivity between Li3InCl6 electrolytes synthesized by different solvents, which can provide a reference for the future synthesis of halide electrolytes and enable their practical application in halide-based ASSLMBs with a high energy density.

Extensively-used rechargeable lithium-ion batteries (LIBs) face challenges in achieving high safety and long cycle life. To address such challenges, ultrathin solid polymer electrolyte (SPE) is fabricated with reduced phonon scattering by depositing the composites of ionic-liquid (1-ethyl-3-methylimidazolium dicyamide, EMIM:DCA), polyurethane (PU) and lithium salt on the polyethylene separator. The robust and flexible separator matrix not only reduces the electrolyte thickness and improves the mobility of Li+, but more importantly provides a relatively regular thermal diffusion channel for SPE and reduces the external phonon scattering. Moreover, the introduction of EMIM:DCA successfully breaks the random intermolecular attraction of the PU polymer chain and significantly decreases phonon scattering to enhance the internal thermal conductivity of the polymer. Thus, the thermal conductivity of the as-obtained SPE increases by approximately six times, and the thermal runaway (TR) of the battery is effectively inhibited. This work demonstrates that optimizing thermal safety of the battery by phonon engineering sheds a new light on the design principle for high-safety Li-ion batteries.

The development of solid polymer electrolytes (SPEs) is impeded by the severe Li-dendrites growth at the un-stable SPE-Li interface. Herein, we demonstrate that the interfacial stability of poly(ethylene oxide) (PEO) electrolytes against Li metal is significantly improved by a shielding strategy, where the nanosheets of a 2D Li+ conductor Li0.46Mn0.77PS3 (LiMPS) serve as nanosized shields to armor PEO against the spears -lithium den-drites. Besides physical inhibition, LiMPS also homogenizes Li+ flux owing to its 2D nature, superior Li+ con-ductivity (2.1 x 10-4 S cm-1 at 30 & DEG;C) and strong adsorption of Li+. This strategy also enables PEO-LiMPS electrolytes to exhibit superior ionic conductivity of 2.6 x 10-4 S cm-1 at 45 & DEG;C, a nearly tenfold increase compared to bare PEO electrolytes. Furthermore, the electrochemical stability window (ESW) of PEO-LiMPS electrolytes is expanded to 4.8 V (3.8 V for pristine PEO). As a result, symmetric Li/PEO-LiMPS/Li cells deliver short circuit-free cycling over 600 h, and LiNi0.8Co0.1Mn0.1O2/PEO-LiMPS/Li batteries also present a high-capacity retention over 80% after 200 cycles at 0.2 C. In addition, LFP/PEO-LiMPS/Li pouch cell retains 93% of the initial capacity after cycling at 0.2 C for 230 cycles. This 2D Li+-conductive shielding strategy provides a unique protective mechanism for SPEs in solid-state Li metal batteries (SSLMBs).

The composition of the solid electrolyte interphase (SEI) is crucial to stably operate solid‐state batteries based on lithium‐metal anodes. In this work, the redox state of the PVDF‐ b ‐PTFE (PVT) solid polymer electrolyte is regulated by introducing fully conjugated copper polyphthalocyanine metal (CuPcLi), improving the electron transfer kinetics to accelerate the decomposition of fluorinated ingredients. As a result, an effective SEI with enriched lithium fluoride forms in situ at the Li/electrolyte interface, which enhances the Li‐ion transport kinetics and regulates the lithium deposition behavior, delivering ultra‐stable lithium plating/stripping performance over 2000 h in the Li//Li half‐cell. In addition, the chemisorption between Cu 2+ and O atoms from TFSI − restrains the movement of anions in the electrolyte, and the CuPcLi improves the lithium ion release, exhibiting a high lithium‐ion conductivity of 0.8 mS cm −1 and a high lithium‐ion transference number of 0.74. As a result, the solid polymer electrolyte of PVT‐10CuPcLi paired with LiFePO 4 delivers fantastic cyclic performance with a capacity retention of 92% even after 1000 cycles at 1 C at room temperature. When paired with high‐voltage LiNi 0.6 Co 0.2 Mn 0.2 O 2 (NCM622) cathode, the cells can be operated at 1 C with superior capacity retention over 88% after 300 cycles.

The application of solid polymer electrolytes (SPEs) is severely impeded by the insufficient ionic conductivity and low Li+ transference numbers (tLi+). Here, we report an iodine‐driven strategy to address both the two long‐standing issues of SPEs simultaneously. Electronegative iodine‐containing groups introduced on polymer chains effectively attract Li+ ions, facilitate Li+ transport, and promote the dissociation of Li salts. Meanwhile, iodine is also favorable to alleviate the strong O−Li+ coordination through a Lewis acid–base interaction, further improving the ionic conductivity and tLi+. As a proof of concept, an iodinated single‐ion conducting polymer electrolyte (IPE) demonstrates a high ionic conductivity of 0.93 mS cm−1 and a high tLi+ of 0.86 at 25 °C, which is among the best results ever reported for SPEs. Moreover, symmetric Li/Li cells with IPE achieve a long‐term stability over 2600 h through the in‐situ formed LiF‐rich interphase. As a result, Li−S battery with IPE maintains a high capacity of 623.7 mAh g−1 over 300 cycles with an average Coulombic efficiency of 99%. When matched with intercalation cathode chemistries, Li/IPE/LiFePO4 and Li/IPE/LiNi0.8Mn0.1Co0.1O2 solid‐state batteries also deliver high‐capacity retentions of 95% and 97% at 0.2 C after 120 cycles, respectively.

Solid polymer electrolytes are the most promising solid electrolytes due to their mechanical flexibility and manufacturing scalability. However, the low lithium-ion transference number and battery failure with detrimental dendrites growth inhibit its commercial application in solid-state batteries. Here amorphous silicon nitride with high permittivity was introduced to both restrain the anion motion and screen the electric potential under external electric field, by which the lithium-ion transference number was improved and the dendrite growth was inhibited significantly. The symmetric Li//Li cell paired with this solid polymer electrolyte exhibits a high lithium-ion transference number of 0.53, with excellent lithium plating/stripping capability at high current density of 1.0 mA cm(-2) over 250 h at room temperature. The practical application of this solid polymer electrolyte is verified by the capacity retention of 86.5% over 500 cycles and 70.5% even after 1000 cycles at room temperature with Li//LiFePO4 pouch cell at 1C. The fire retardant of this solid polymer electrolyte is demonstrated by an excellent self-extinguish behavior (< 1 s) in the flame test. Additionally, this solid polymer electrolyte system presents an effective strategy for enhancing anode interfacial stability for other battery systems.

The development of polymer-based solid-state batteries is severely limited by the low ionic conductivity of solid polymer electrolyte and the instable interface between polymer electrolyte and Li-metal anode. In this work, lithium iodide (LiI) as a bifunctional additive was introduced into the poly(ethylene oxide) (PEO)-based electrolyte to improve the ionic conductivity and to construct a stable interphase at the Li/PEO interface. I anions offer a strong electrostatic interaction with hydrogen atoms on PEO chains (H-PEO) and forming massive I-H bonds that cross-link PEO chains, decrease crystallinity of PEO, and thus improve Li+ interchain transport. In addition, LiI participates in the formation of an inorganic-rich interphase layer, which decreases the energy barrier of Li+ transport across the interface and thus inhibits the growth of lithium dendrites. As a result, the composite PEO electrolyte with 2 wt% LiI (PEO-2LiI) presents a very high ionic conductivity of 2.1 x 10(-4) S cm(-1) and a critical current density of 2.0 mA cm(-2) at 45 degrees C. Li symmetric cell with this PEO-2LiI electrolyte exhibits a long-term cyclability over 600 h at 0.2 mA cm(-2). Furthermore, solid-state LiFePO4 and LiNi(0.8)Mn(0.4)Co(0)(.1)o(2) batteries with the PEO-2LiI electrolyte show an impressive electrochemical performance with outstanding cycling stability and rate capability at 45 degrees C. (C) 2022 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by ELSEVIER B.V. and Science Press. All rights reserved.

The huge market in electric road vehicles and portable electronic devices is boosting the development of high-energy-density solid-state alkali-metal batteries with high safety, including lithium-metal batteries and sodium-metal batteries. However, solid-state electrolytes (SSEs) are still the main barrier that hinders the development of solid-state alkali-metal batteries, because there is no such a single SSE that is compatible with both the highly reductive and chemically active alkali-metal anodes and oxidative high-voltage cathodes. Asymmetric solid-state electrolytes (denoted as ASEs) with more than one layer of SSE are reported to be able to effectively tackle such issues by constructing a multiple layered-like structure. In ASEs, each layer of SSE contains a different composition or morphology. SSEs with such an asymmetric structure exhibit Janus property, which not only satisfies the different stability requirements from the cathode and the anode respectively, but also compensates the disadvantages of the individual SSEs ingenuously. In this way, the advantages of each individual SSE are fully utilized and superior electrochemical performances of solid-state full cells are realized. This review focuses on discussing various original ASEs that have been developed recently, including design principles, synthetic methods of bilayer/tri-layer structured polymer/ceramic ASEs and asymmetric gel electrolytes, and the exhibited electrochemical properties of solid-state lithium/sodium-metal batteries. Finally, we provide perspectives and suggestions towards ASEs for future applications in solid-state batteries.

Erase count is a key performance indicator of hard drives, and it shows the lifetime of a device. Analysis of erase counts helps us understand the performance of a device and prevent the failure of it. In this paper, a machine learning based framework is proposed to predict the curves of erase counts. Specifically, probabilities and erase-count curves of different hard drives are first calculated from training data. The probabilities are for deciding disk type in testing data. The erase-count curves from training data serve as references to testing data. Long short-term memory is utilized to model the erase-count difference between a reference device and a testing device, and to predict the lifetime of the testing device. Preliminary results of synthetic data show that our method can follow references and precisely predict erase counts.

The novel h-BN/glass compressive seals were investigated for use in solid oxide fuel cell. The glass was mixed with h-BN powders to obtain composite materials using tape casting technique. Leakage rates were measured below 0.012 sccm/cm under input gas pressure of 6.8 kPa. Seals containing 40% by weight glass showed excellent thermal cycle and long-term operation stability. The leakage rates were reduced by more than half after ten thermal cycles under different input gas pressure. Also, the leakage rates gradually decreased to 0.008 sccm/cm under input gas pressure of 20.4 kPa at 750 degrees C during 208 h, and then remained stable. These observations can be explained by liquid B2O3 films having gradually formed on the h-BN surface. Boron oxidation effectively improved bondage for both interface and interior particles. This phenomenon was interpreted by seals' microstructure analyses and transmission electron microscopy. Finally, an evolution model is proposed to explain the process. (C) 2020 Elsevier B.V. All rights reserved.