Recent Advances in Electrolytes for High-Voltage Cathodes of Lithium-Ion Batteries

With the increasing scale of energy storage,it is urgently demanding for further advancements on battery technologies in terms of energy density,cost,cycle life and safety.The development of lithium-ion batteries(LIBs)not only relies on electrodes,but also the functional electrolyte systems to achieve controllable formation of solid electrolyte interphase and high ionic conductivity.In order to satisfy the needs of higher energy density,high-voltage(>4.3 V)cathodes such as Li-rich layered compounds,olivine LiNiPO_(4),spinel LiNi_(0.5)Mn_(1.5)O_(4) have been extensively studied.However,high-voltage cathodebased LIBs fade rapidly mainly owing to the anodic decomposition of electrolytes,gradually thickening of interfacial passivation layer and vast irreversible capacity loss,hence encountering huge obstacle toward practical applications.To tackle this roadblock,substantial progress has been made toward oxidation-resistant electrolytes to block its side reaction with high-voltage cathodes.In this review,we discuss degradation mechanisms of electrolytes at electrolyte/cathode interface and ideal requirements of electrolytes for high-voltage cathode,as well as summarize recent advances of oxidation-resistant electrolyte optimization mainly from solvents and additives.With these insights,it is anticipated that development of liquid electrolyte tolerable to high-voltage cathode will boost the large-scale practical applications of high-voltage cathode-based LIBs.

A review of fire-extinguishing agent on suppressing lithium-ion batteries fire

Safety issue of lithium-ion batteries(LIBs)such as fires and explosions is a significant challenge for their large scale applications.Considering the continuously increased battery energy density and wider large-scale battery pack applications,the possibility of LIBs fire significantly increases.Because of the fast burning and the easy re-ignition characteristics of LIBs,achieving an efficient and prompt LIBs fire suppression is critical for minimizing the fire hazards.Different from conventional fire hazards,the LIBs fire shows complicated and comprehensive characteristics,and an effective and suitable fire-extinguishing agent particularly designed for LIBs is highly desirable.Considerable efforts have been devoted to this topic,to the best of our knowledge,a comprehensive review on this regard is still rare.Moreover,in practice,a guidance for the design and selections of a proper fire-extinguishing agent for LIBs is urgently needed.Herein,the special mechanisms and characteristics for LIBs fire and the corresponding design principles for LIBs fire-extinguishing agent were introduced.It is revealed that a fire-extinguishing agent developed for LIBs fire will most likely need a high heat capacity,high wetting,low viscosity and low electrical conductivity.After a comprehensive comparison of these agents in terms of these performances,water-based fire-extinguishing agents show best.Several typical fire-extinguishing agents such as gaseous agents,dry powders,water-based and aerosol fire-extinguishing agents were then introduced,and their fire extinguishment mechanisms were presented.Finally,their effectiveness in suppressing the fire were summarized.Water-based fire-extinguishing agents possess high cooling capacity and excellent anti-reflash performance for the fire.We believe this review could shed light on developing an efficient fire-extinguishing agent particularly designed for LIBs.

A thermoresponsive composite separator loaded with paraffin@SiO_(2) microparticles for safe and stable lithium batteries

Lithium-ion batteries (LIBs)-related accidents have been reported for years and safety issues are stumbling blocks for the practical applications of lithium metal batteries (LMBs) with higher energy density. More effective strategies to shut down the battery at the early stage of thermal runaway with less side effects on the electrochemical performance are greatly desired. In this work, the core–shell structural paraffin@SiO_(2) microparticles were synthesized by in situ emulsion interfacial hydrolysis and polycondensation and the paraffin@SiO_(2)-loaded separator (PSS) was prepared by a facile filtration method. The introduction of hydrophilic silica shells in paraffin@SiO_(2) enhanced the wettability of carbonate electrolyte with the composite separator and improved the processability of soft paraffin. As a result, when used in LMBs at room temperature, the cell with PSS inside had a more uniform deposition of lithium, a much lower overpotential and a more stable electrochemical performance than the cell with the blank separator or the conventional pure paraffin-loaded separator inside. More significantly, when a heating stimulation (i.e. 115 ℃) was subjected to the cell with PSS inside, the paraffin in the core of paraffin@SiO_(2) could be released, blocking the gaps between particles and the pores in the separator and efficiently stopping the transportation of Li+ between two electrodes, resulting in the thermally-induced shutdown of the cell below the melting temperature of PE (~135 ℃) in the Celgard2325 separator. The core–shell structure of paraffin@SiO_(2) enables the maintaining of each component’s benefits while avoiding each one’s drawbacks by elaborating microstructural design. Therefore, the conventional dilemma between the electrochemcial performance and safety of LMBs could be solved in the future.

Regulating the growth of lithium dendrite by coating an ultra-thin layer of gold on separator for improving the fast-charging ability of graphite anode

With the ever-growing application of lithium-ion batteries(LIBs), their fast-charging technology has attracted great interests of scientists. However, growth of lithium dendrites during fast charge of the bat teries with high energy density may pose great threats to the operation and cause serious safety issues Herein, we prepared a functional separator with an ultra-thin(20 nm) layer of Au nanoparticles deposited by evaporation coating method which could regulate growth direction and morphology of the lithium dendrites, owing to nearly zero overpotential of lithium meal nucleation on lithiated Au. Once the Li den drites are about to form on the graphite anode during fast charging(or lithiation), they plate predomi nantly on the Au deposited separator rather than on the graphite. Such selective deposition does no compromise the electrochemical performance of batteries under normal cycling. More importantly, i enables the better cycling stability of batteries at fast charge condition. The Li/Graphite cells with Au nanoparticles coated separator could cycle stably with a high areal capacity retention of 90.5% over 95 cycles at the current density of 0.72 m A cm^(-2). The functional separator provides an effective strategy to adjust lithium plating position at fast charge to ensure high safety of batteries without a compromise on the energy density of LIBs.

Zwitterionic Matrix with Highly Delocalized Anionic Structure as an Efficient Lithium Ion Conductor

The leakage and volatilization of liquid electrolytes raise potential safety risks in the development of electrochemical energy storage devices with high energy density.Herein,novel solid-state zwitterionic materials containing sulfonyl imide as a highly delocalized anionic structure were synthesized for highly targeted lithium ion conducting matrices.The influences of the molecular structure characteristics on thermal behavior and electrochemical property were investigated comprehensively.Due to the weak Coulomb interaction between the sulfonyl imide moiety and cationic species,the rationally designed zwitterionic electrolytes showed a high conductivity of 0.44 mS cm^(-1).And the obtained high lithium ion transference number of 0.43 is four times higher than that of the widely employed sulfonate analogues.Additionally,excellent cycling stability of the lithium plating/stripping process and super resistance to electrochemical oxidation(up to 5.5 V)were observed.This molecular engineering strategy for lithium ion conductor advances new possibilities for developing solvent-free and non-migrating electrolyte matrix materials for lithium metal batteries.

小鼠杂交瘤单克隆抗体快速制备技术研究进展

小鼠杂交瘤单克隆抗体来源稳定、后期易制备、产量高,是免疫学中使用最为普遍的抗体。传统的耗时费力的杂交瘤制备技术无法满足日益增长的市场需求。文中从抗原设计筛选、B细胞富集与筛选、骨髓瘤细胞的改造、融合技术的改进、阳性杂交瘤细胞筛选及单克隆抗体性能快速测定中所涉及的快速制备技术方面进行阐述,以期为系统化的小鼠杂交瘤单克隆抗体的快速制备方法提供参考。

单增李斯特菌生物膜形成调控机制的研究进展

单增李斯特菌是一种重要的食源性病原菌。单增李斯特菌的分布和存活与其形成生物膜的能力有关,生物膜对逆性环境有抵抗力,细菌会从生物膜中分离导致食品持续性的污染。生物膜的形成、成熟和结构取决于多种外部和内部因素,并且多种调控机制起着重要作用。文中旨在阐述单增李斯特菌生物膜形成过程中的调控机制(包括胞内作用、胞间作用和种间作用),以控制食品加工环境中致病性生物膜的形成,从而为食品安全提供新的干预策略。