A panoramic view of Li7P3S11 solid electrolytes synthesis,structural aspects and practical challenges for all-solid-state lithium batteries

The development of an inorganic electrochemical stable solid-state electrolyte is essentially responsible for future state-of-the-art all-solid-state lithium batteries (ASSLBs). Because of their advantages in safety, working temperature, high energy density, and packaging, ASSLBs can develop an ideal energy storage system for modern electric vehicles (EVs). A solid electrolyte (SE) model must have an economical synthesis approach, exhibit electrochemical and chemical stability, high ionic conductivity, and low interfacial resistance. Owing to its highest conductivity of 17 mS·cm^-1, and deformability, the sulfide-based Li₇P₃S₁₁ solid electrolyte is a promising contender for the high-performance bulk type of ASSLBs. Herein, we present a current glimpse of the progress of synthetic procedures, structural aspects, and ionic conductivity improvement strategies. Structural elucidation and mechanistic approaches have been extensively discussed by using various characterization techniques. The chemical stability of Li₇P₃S₁₁ could be enhanced via oxide doping, and hard and soft acid/base (HSAB) concepts are also discussed. The issues to be undertaken for designing the ideal solid electrolytes, interfacial challenges, and high energy density have been discoursed. This review aims to provide a bird's eye view of the recent development of Li₇P₃S₁₁-based solid-state electrolyte applications and explore the strategies for designing new solid electrolytes with a target-oriented approach to enhance the efficiency of high energy density all-solid-state lithium batteries.     

Room-Temperature Solid-State Lithium Metal Batteries Using Metal Organic Framework Composited Comb-Like Methoxy Poly(ethylene glycol) Acrylate Solid Polymer Electrolytes

Solid polymer electrolyte with good thermal stability and flexibility is an excellent candidate for solid-state lithium metal batteries, while its low ionic conductivity caused by high crystallinity limits its application at ambient temperature. Here a metal organic framework (zeolitic imidazolate framework-8, ZIF-8) composited comb-like methoxy poly(ethylene glycol) acrylate polymer electrolyte (MCPE) with high ionic conductivity (9.96 × 10⁻⁵ S cm⁻¹ at 30 °C) is prepared by an in situ UV polymerization method. The as-prepared MCPE exhibits improved mechanical property due to the introduction of porous ZIF-8 nanofillers, which is beneficial to suppress the growth of lithium dendrites. Consequently, the LiFePO₄||MCPE||Li cells show a high capacity of 116 mAh g⁻¹ at 30 °C and 0.5 C, and maintain 89.4% of initial capacity after 150 cycles with the average Coulombic efficiency of 99.9%. These results demonstrate that the MCPE shows great potential in solid-state lithium metal batteries near room temperature.     

Direct-Ink-Writing of Electroactive Polymers for Sensing and Energy Storage Applications

Considering the high levels of materials used in the fields of electronics and energy storage systems, it is increasingly necessary to take into consideration environmental impact. Thus, it is important to develop devices based on environmentally friendlier materials and/or processes, such as additive manufacturing techniques. In this work, poly(vinylidene fluoride) (PVDF) and poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) are prepared by direct-ink-writing (DIW) by varying solvent evaporation temperature and fill density percentage. Different morphologies for both polymers are obtained, including dense films and porous membranes, as well as different electroactive β-phase content, thermal and mechanical properties. The dielectric constant and piezoelectric d₃₃ coefficient for dense films reaches up to 16 at 1 kHz and 4 pC N⁻¹, respectively for PVDF-HFP with a fill density of 80 and a solvent evaporation temperature of 50 °C. Porous structures are developed for battery separator membranes in lithium-ion batteries, with a highest ionic conductivity value of 3.8 mS cm⁻¹ for the PVDF-HFP sample prepared with a fill density of 100 and a solvent evaporation temperature of 25 °C, the sample showing an excellent cycling performance. It is demonstrated that electroactive films and membranes can be prepared by direct-ink writing suitable for sensors/actuators and energy storage systems.     

Phase transition of lithiated-spinel Li2Mn2O4 at high temperature

1 Introduction Lithium manganese oxides are the most attractive cathode materials for rechargeable lithium-ion batteries because of their low-cost and less toxicity when compared with either cobaltates or nickelates[1?3]. Among these oxides, the spinel-fr…     

锂离子电池正极材料第一原理计算研究

利用第一原理计算方法可分析和预测锂-金属氧化物电池正极材料在Li离子嵌入脱出过程中的电势和稳定性等性能。本文详细介绍了第一原理计算方法的理论背景以及目前LiCoO2正极材料计算研究的现状。利用此方法对LiNiO2及多组分材料掺杂进行研究是今后工作的重点。     

Synthesis and electrochemical properties of Th-doped LiMn2O4 powders for lithium-ion batteries

To improve the cycle performance of eco-friendly and cost-effective spinel LiMN2O4 as the Li secondary batteries, the Th-doped LiThxMn1-xO4 spinel powers were synthesized by solid-state method. The starting materials, Li2CO3,MnO2 and Th(NO3)4·4H2O, were mixed uniformly using a traditional ball milling, which resulted in a uniform particle size distribution in the mixed powers. Tests of X-ray diffraction, SEM, impedance spectra and charge-discharge were carried out for LiThxMn1-xO4 cathode materials. Results show that the synthesized LiTh0.01Mn1.99O4 material exhibits standard spinel structure, regular particle morphology and excellent property of charge-discharge for big current. The capacity retention of the material modified by doping Th is more than 85.1% of the first discharge specific capacity of 111.5 mAh·g -1 after 20 cycles at the current rate 1C, while the pristine LiMN2O4 is only 57% of the first discharge specific capacity of 110.2 mAh·g-1 after the same cycles at the same current rate.     

软段含离子基团的阴离子型水性聚氨酯胶粘剂的研究(Ⅱ)——硬段结构的影响

以含有不同离子基团的聚酯多元醇为软段,采用丙酮法合成了一系列水性聚氨酯乳液。研究了不同硬段结构和硬段含量和扩链剂对其干膜物理机械性能和吸水率的影响。     

有机硅氧烷改性水性聚氨酯的合成

采用有机硅氧烷单体与聚醚、二羟甲基丙酸（DMPA）和甲苯二异氰酸酯（TDI）反应制备水性聚氨酯涂料。研究结果表明采用后添加有机硅氧烷单体的合成工艺，可制备贮存稳定好的水性聚氨酯乳液；凝胶渗透色谱（GPC）分析表明有机硅氧烷改性水性聚氨酯提高了聚氨酯的相对分子质量；性能测试表明有机硅氧烷改性水性聚氨酯涂料具有明显的优点：涂膜硬度高，耐沾污性、耐水性好和耐溶剂性好。