Hexafluoroisopropyl Trifluoromethanesulfonate-Driven Easily Li+ Desolvated Electrolyte to Afford Li||NCM811 Cells with Efficient Anode/Cathode Electrolyte Interphases

Solid electrolyte interphase (SEI) and cathode electrolyte interphase (CEI) with optimized components and structures are considered to be crucial for lithium-ion batteries. Here, gradient lithium oxysulfide (Li₂SO_x, x = 0, 3, 4)/uniform lithium fluoride (LiF)-type SEI is designed in situ by using hexafluoroisopropyl trifluoromethanesulfonate (HFPTf) as electrolyte additive. HFPTf is more likely to be reduced on the surface of Li anode in electrolytes due to its high reduction potential. Moreover, HFPTf can make Li⁺ desolvated easily, leading to the increase in the flux of Li⁺ on the surface of Li anode to avoid the growth of Li dendrites. Thus, the cycling stability of Li||Li symmetric cells is improved to be 1000 h at 0.5 mA cm⁻². In addition, HFPTf-contained electrolyte could make Li||NCM811 batteries with a capacity retention of 70% after 150 cycles at 100 mA g⁻¹, which is attributed to the formation of uniform and stable CEI on the cathode surface for hindering the dissolvation of metal ions from the cathode. This study provides effective insights on the strong ability of additives to adjust electrolytes in “one phase and two interphases” (electrolyte and SEI/CEI).     

Ultralong‐Life Chloride Ion Batteries Achieved by the Synergistic Contribution of Intralayer Metals in Layered Double Hydroxides

Chloride ion batteries (CIBs) are a promising type of energy storage device due to their high theoretical volumetric energy density and abundant reserves of chlorine‐containing precursors. However, the unsatisfactory cycling performance and structural instability of cathode materials hinder their practical application. In this work, layered double hydroxides (LDHs), which consist of a trimetallic NiVAl hydroxide host matrix and interlayer Cl^?, are demonstrated to be high‐performance cathode materials for CIBs. The Ni₂V_0.9Al_0.1‐Cl LDH is capable of delivering a high initial capacity of 312.2 mAh g^?1 at 200 mA g^?1 and an ultralong life over 1000 cycles (with a capacity higher than 113.8 mAh g^?1). Such a long cycling life exceeds that of any reported CIBs. The remarkable Cl^?‐storage performance of the Ni₂V_0.9Al_0.1‐Cl LDH is ascribed to the synergetic contributions from V^m+ (high redox activity), Ni²⁺ (favorable electronic structure), and inactive Al³⁺ (enhances the structural stability), which is revealed by a comprehensive study that utilizes synchrotron X‐ray absorption near‐edge structure experiments, kinetic investigations, and theoretical calculations. This study provides an effective strategy to achieve superior rechargeable batteries, which are applicable to large‐scale energy storage and power grids.     

Rational Design of Binders for Stable Li‐S and Na‐S Batteries

Binders play a critical role in stabilizing the sulfur cathode of Li‐S and Na‐S batteries. Over the past decade, the design of binder molecules has gone through tremendous evolution from primarily maintaining the structural integrity of the electrode against volume change to rationally immobilizing polysulfide intermediate and facilitating electron/ion transport in the charge and discharge process. This article reviews the development of binder for Li‐S and Na‐S batteries from the perspective of molecular design, and comprehensively discusses the correlation between the functions of the binder molecules and the cell performance. It also points out the future challenge and the potential solutions to address them.     

Faster Activation and Slower Capacity/Voltage Fading: A Bifunctional Urea Treatment on Lithium‐Rich Cathode Materials

Li‐rich layered oxides are promising cathode materials for next‐generation Li‐ion batteries because of their extraordinary specific capacity. However, the activation process of the key active component Li₂MnO₃ in Li‐rich materials is kinetically slow, and the complex phase transformation with electrode/electrolyte side reactions causes fast capacity/voltage fading. Herein, a simple thermal treatment strategy is reported to simultaneously tackle these challenges. The introduction of a urea thermal treatment on Li‐rich material Li_1.87Mn_0.94Ni_0.19O₃ leads to oxygen deficiencies and partially reduced Mn ions on the oxide surface for activating the Li‐rich phase. In situ synchrotron study confirms that the urea‐treated cathode shows much faster Li extraction from both Li and transition metal layers with less oxygen evolution upon charging than that of untreated counterparts. Moreover, the decomposition products of urea during thermal treatment subsequently deposit on the surface of cathode material, leading to a unique passivation layer against side reactions between electrode and electrolyte. Soft X‐ray absorption spectroscopy reveals the structural evolution mechanism with a significantly suppressed dissolution of Mn species over cycling measurement. The urea‐treated Li_1.87Mn_0.94Ni_0.19O₃ shows accelerated activation kinetics to reach high capacity of 270 mA h g^–1 and demonstrates excellent capacity retention of 98.49% over 300 cycles with slower voltage decay.     

Advancements and Challenges in Potassium Ion Batteries: A Comprehensive Review

Demand for energy in day to day life is increasing exponentially. However, existing energy storage technologies like lithium ion batteries cannot stand alone to fulfill future needs. In this regard, potassium ion batteries (KIBs) that utilize K ions in their charge storage mechanism have attracted considerable attention due to their unique properties and are therefore established as one of the future battery systems of interest among the scientific community. Nevertheless, the development and identification of appropriate electrode materials is very essential for practical applications. This review features the current development in KIBs electrode and electrolyte materials, the present challenges facing this technology (in the commercial aspect), and future aspects to develop fully functional KIBs. The potassium storage mechanisms, evolution of the KIBs, and the advantages and disadvantages of each category of materials are included. Additionally, various approaches to enhance the electrochemical performances of KIBs are also discussed. This review is not only an amalgamation of different viewpoints in literature, but also contains concise perspectives and strategies. Moreover, the potential emergence of a novel class of K‐based dual ion batteries is also analyzed for the first time.     

用于热阴极的热子绝缘层研究

研究了热子涂层的原材料粒度对热子绝缘层质量的影响,粒度过细或过粗,涂层附着不均匀,烧结后涂层表面开裂、起皮、粗糙、掉粉严重。采用粒度级配的配比方案制备了氧化铝涂层,电镜分析表明,涂层致密,质量得到明显改善;与原有工艺相比,氧化铝涂层抗压能力提高了1倍。     

基于碳纳米管薄膜构建场发射平面显示器的阴极结构

碳纳米管场发射平面显示器具有工作电压低、功耗低和制造成本低等优势,近年来基于碳纳米管场发射平面显示器的研究与应用研发已成为显示技术领域研究的热点之一,并已取得丰富成果。简要回顾了碳纳米管用于场发射的机理以及用于场发射平面显示器的优势,主要介绍了碳纳米管用于场发射平面显示器研究的一些进展和一些亟待解决的问题,包括碳纳米管阴极薄膜的制备、碳纳米管阴极工作稳定性与寿命的改进以及阴极结构的设计等,并展望了碳纳米管用于场发射平面显示器的发展前景。     

锂空气电池性能改善方法的研究进展

锂空气电池是一种高能量密度的清洁储能设备,其应用对于缓解能源危机和环境压力具有重要意义。当前,锂空气电池性能仍受到阳极锂腐蚀、电解质分解、充放电效率低的影响。本文结合国内外研究最新进展,从阳极锂保护、电解质及添加剂的使用、氧化还原中间体和多孔阴极结构等方面探讨改善锂空气电池稳定性、提高放电产物分解速度、降低充放电过电位的方法,并对锂空气电池的应用前景进行展望。     

Ordered SnO nanoparticles in MWCNT as a functional host material for high-rate lithium-sulfur battery cathode

Lithium-sulfur battery has become one of the most promising candidates for next generation batteries,and it is still restricted due to the low sulfur conductivity,large volume expansion and severe polysulfide shuttling.Herein,we present a novel hybrid electrode with a ternary nanomaterial based on sulfur-impregnated multiwalled carbon nanotubes filled with ordered tin-monoxide nanoparticles (MWCNT-SnO/S).Using a dry plasma reduction method,a mechanically robust material is prepared as a cathode host material for lithium-sulfur batteries.The MWCNT-SnO/S electrode exhibits high conductivity,good ability to capture polysulfides,and small volume change during a repeated charge-discharge process.In situ transmission electron microscopy and ultraviolet-visible absorption results indicate that the MWCNT-SnO host efficiently suppresses volume expansion during lithiation and reduces polysulfide dissolution into the electrolyte.Furthermore,the ordered SnO nanoparticles in the MWCNTs facilitate fast ion/electron transfer during the redox reactions by acting as connective links between the walls of the MWCNTs.The MWCNT-SnO/S cathode with a high sulfur content of 70 wt.％ exhibits an initial discharge capacity of 1,682.4 mAh·g-1 at 167.5 mA·g-1 (0.1 C rate) and retains a capacity of 530.1 mAh·g-1 at 0.5 C after 1,000 cycles with nearly 100％ Coulombic efficiency.Furthermore,the electrode exhibits the high capacity even at a high current rate of 20 C.     

锂硫二次电池硫基正极材料的研究进展

作为新一代的储能体系,锂硫二次电池以高的理论能量密度(2 600 m Ah/g),廉价的正极材料以及环境友好等特点受到广泛的关注。但是,由于硫的绝缘性和充放电过程中体积的膨胀、锂硫之间复杂的电化学反应及其产物多硫化物的溶解性等诸多问题的存在,阻碍了锂硫二次电池走向商业化。本文从无机金属化合物与硫复合、导电高分子与硫复合、纳米碳及其衍生物与硫复合,以及三元复合等方面出发,综述了近年来锂硫电池正极材料的研究现状,并展望了该材料的未来发展趋势。