隔膜表面改性法改进锂金属电极循环性能

采用等离子体接枝的方法在聚丙烯(PP)隔膜表面接枝锂磺酸根(SO3Li)基团以及甲基丙烯酸甲酯(MMA)基团.将隔膜与金属锂组装成对称电池采用恒流长时间放电、恒流充放电循环以及交流阻抗方法研究接枝的表面官能团对金属锂电极上锂沉积/溶解过程的影响.实验结果证实,表面接枝MMA和SO3Li官能团可有效促进锂的沉积/溶解动力学,降低界面电阻,抑制金属锂在反复溶解/沉积循环中枝晶的形成.     

La0.6Sr0.4Co0.2Fe0.8O3-δ基固体氧化物电解池复合阳极的制备及性能

采用丝网印刷工艺制备了带有SDC阻挡层的固体氧化物电解池La0.6Sr0.4Co0.2Fe0.8O3-δ(LSCF)基复合阳极,利用动电位扫描及电化学阻抗谱分析考察了该材料在800℃时的电化学性能,电化学阻抗谱的研究表明,O2-在电极发生氧化反应生成O2的反应速率由电极/阻挡层界面的电荷转移、阻挡层/电解质界面的电荷转移以及氧气的解离吸附或在电极表面的扩散等三个电极过程控制.扫描电镜分析表明,经过长时间的电化学测试及升降温,阻挡层与电解质及复合电极部分均结合紧密,无缺陷.通过与传统的LSM-YSZ复合阳极的极化性能的对比,显示出LSCF材料在SOEC阳极领域良好的应用前景.     

人造固态电解质界面在锂金属负极保护中的应用研究EI北大核心CSCD

锂金属具有最低的氧化还原电位(-3.04V vs标准氢电极)和极高的比容量(3860mAh·g^-1),是理想的锂二次电池负极材料.然而电化学循环过程中,由于锂的不均匀成核生长,其表面产生锂枝晶,锂枝晶持续生长会刺穿隔膜,造成电池短路甚至引发火灾.因此需要对锂金属负极进行保护,抑制负面问题,发挥高性能.人造固态电解质界面技术是一种有效的锂金属负极保护策略,本质是预先在锂金属表面涂覆上保护层,保护层具有较高的离子传导性和电化学稳定性、较好的阻隔性和机械强度,可得到高效率、长寿命和无枝晶的锂金属负极.本文将近年来人造固态电解质界面在锂金属负极保护中的研究进展进行综述,对其制备方法、结构特点、锂金属负极循环性能、全电池电化学性能等方面作了详细介绍,分析当前存在问题并指出锂金属负极研究不仅需要加深机理研究还得与实际应用相结合.     

钾盐添加剂改善天然石墨负极的嵌脱锂性质

于1mol/L LiClO₄/EC+DEC电解液中添加不同的钾盐可以显著降低天然石墨电极首次循环过程中的不可逆容量损失, 提高电极的可逆容量和倍率充放电性能. 交流阻抗和电极表面固体电解质相界面(SEI)膜组分的FTIR分析表明, 添加一定量的钾盐可以降低SEI膜的锂盐含量, 有助于形成Li+迁移性良好的SEI膜.     

纳米Al2O3包覆LiFePO4/C正极材料的结构和电化学性能（英文）

主要研究了纳米氧化铝包覆对LiFePO4/C复合正极材料结构和电化学特性的影响。采用溶胶凝胶方法把纳米氧化铝包覆在商业LiFePO4/C颗粒表面。研究了Al2O3包覆层的量对LiFePO4电极在室温和高温充放电性能的影响。结果显示:2wt%Al2O3包覆层能有效增加电池的循环容量,能延缓电池在高温条件下充放电的容量衰减,减小电极的界面阻抗。这归因于氧化铝包覆层对磷酸铁锂晶粒的表面起保护作用,减少电解液对磷酸铁锂晶粒表面的腐蚀,从而改善循环过程中磷酸铁锂的表面结构的完整和稳定,确保锂离子扩散通道的畅通。     

用于微电池的超高功率密度铁氧硫化物薄膜（英文）

作为微电池的核心指标之一,面积功率密度决定了微电池与应用于物联网的微电子器件集成时所需的面积.目前,由于微电子器件尺寸有限,微电池的实际应用受到低面积功率密度的限制.本文研究发现,经过原位等离子体预处理衬底后,溅射的铁氧硫化物薄膜(FeO_xS_y)具备超高功率特性.这种原位等离子体预处理可作为一种通用的界面优化策略来抑制长循环过程中的机械衰变.该正极薄膜展现出极高的功率密度和稳定的循环性能,这是由其高度的结构完整性(强大的界面粘附性和应力释放的岛)、完美的电化学可逆性以及近表面电荷交换(赝电容锂存储机制)的协同作用导致的.预处理的FeO_xS_y薄膜可以输出高达14.6 mW cm^-2的功率密度和291μW h cm^-2μm^-1的体积能量密度.制备得到的正极薄膜的功率密度优于已报道的具有相当面积容量的溅射薄膜.本工作提出了一种简单且高效的预处理方法来制备具有超高功率密度且稳定的微电池薄膜电极.     

聚酯粉末涂层在模拟海洋环境中的腐蚀行为

采用金相显微镜和交流阻抗谱研究了涂层缺陷以及不同前处理工艺对建筑铝合金6063在0.6mol/L NaCl溶液(pH=7.0)中的腐蚀行为。结果表明:未经铬酸钝化处理的铝合金缺陷粉末涂层在0.6mol/L NaCl溶液(pH=7.0)中浸泡50d后,其划痕处堆满腐蚀产物,涂层色差变化较大,划痕两侧无明显腐蚀,其腐蚀速率比浸泡相同时间的经铬酸钝化处理的铝合金粉末涂层约高5倍,铝合金钝化膜能延缓腐蚀,提高缺陷涂层和完整涂层的阻抗。     

人造固态电解质界面在锂金属负极保护中的应用研究

锂金属具有最低的氧化还原电位(-3.04 V vs标准氢电极)和极高的比容量(3860 mAh·g~(-1)),是理想的锂二次电池负极材料。然而电化学循环过程中,由于锂的不均匀成核生长,其表面产生锂枝晶,锂枝晶持续生长会刺穿隔膜,造成电池短路甚至引发火灾。因此需要对锂金属负极进行保护,抑制负面问题,发挥高性能。人造固态电解质界面技术是一种有效的锂金属负极保护策略,本质是预先在锂金属表面涂覆上保护层,保护层具有较高的离子传导性和电化学稳定性、较好的阻隔性和机械强度,可得到高效率、长寿命和无枝晶的锂金属负极。本文将近年来人造固态电解质界面在锂金属负极保护中的研究进展进行综述,对其制备方法、结构特点、锂金属负极循环性能、全电池电化学性能等方面作了详细介绍,分析当前存在问题并指出锂金属负极研究不仅需要加深机理研究还得与实际应用相结合。     

坚韧、弹性的氟化固体电解质界面稳定碳酸酯电解质中的锂金属（英文）

锂金属负极和碳酸酯类电解液之间不稳定的界面是限制高比能锂金属电池循环寿命的关键挑战.本文使用含苯环的双酚A乙氧基化物二甲基丙烯酸酯(BAED)交联剂调节聚(丙烯酸六氟丁酯)(PHFBA),设计了一种弹性人造固体电解质中间相(RASEI)来解决这个问题.刚性BAED分子可以对柔性PHBA基体进行调控,实现从600%伸长率到90%压缩率的卓越回弹性,并具有超过2 MPa的高杨氏模量.RASEI可以适应锂金属较大的体积变化,并确保电池运行过程中锂金属与RASEI之间的紧密接触,促进均匀的锂沉积并减少副反应.因此,经过RASEI修饰的Li‖Li对称电池可以在1 mA cm^-2和1 mAh cm^-2下实现超过500小时的长期循环.对循环后锂金属进行测试分析表明锂枝晶的生长得到了有效的抑制.此外,搭配20 mg cm^-2高阴极负载的NCM811软包电池在1 C下,经过200次循环后容量保持率超过85%.     

304不锈钢表面化学钝化膜对Sn粘附行为的影响

为了研究化学酸洗钝化在低熔点金属Sn与304不锈钢粘附过程中的作用,通过浸泡腐蚀实验分析了液态Sn与U型弯曲后的酸洗钝化不锈钢的交互作用行为,探讨了Sn粘附对不锈钢基体浸泡腐蚀性能的影响.实验结果表明:Sn与304不锈钢相互作用在界面处形成了片状(Fe,Cr)Sn2化合物冶金层,酸洗钝化处理改变了冶金结合,使液态Sn与304不锈钢界面成为直接物理接触;U型弯曲破坏了钝化膜的完整性,未能阻止Sn与不锈钢的界面冶金结合,但降低了界面化合物层的厚度.浸泡腐蚀实验结果表明,Sn粘附层促进了不锈钢基体腐蚀.     

Preparation and characterization of lithium-boron alloys: electrochemical studies as anodes in molten salt media,and comparison with pure lithium-involving systems

Because of its low melting point (180.5°C), lithium cannot be used as a negative electrode in high current density generators (particularly thermally activated batteries). The lithium-boron alloy, first discovered in 1978, presents advantageous properties: it remains solid and stable up to 650°C and its electrochemical behaviour is very close to that of pure lithium. Conditions of synthesis of a metal lithium-rich alloy have been analysed; the multiphase material consisted of a porous refractory matrix filled with pure metal lithium, it was studied by nuclear magnetic resonance and its matrix examined by electron microscopy and porosimetry. Lithium-boron alloy electrochemical properties were analysed in LiCl-KCl media. In a flooded electrolyte, the behaviour of LiB is similar to that observed in non-aqueous media, particularly in dioxolane (DOL)-1.5 m LiAsF₆. In the case of single cell discharges (starved electrolyte), some problems arose from the nature of the electrolyte used (LiCl-KCl+SiO₂), which were solved by the substitution of SiO₂ by MgO in the electrolyte. Discharge curves were then identical to those obtained in flooded electrolytes and were characterized by two plateaux corresponding to the discharge of metallic lithium, and ionic lithium from the matrix, respectively.     

Additional Lithium Storage on Dynamic Electrode Surface by Charge Redistribution in Inactive Ru Metal

Beyond a traditional view that metal nanoparticles formed upon electrochemical reaction are inactive against lithium, recently their electrochemical participations are manifested and elucidated as catalytic and interfacial effects. Here, ruthenium metal composed of ≈5 nm nanoparticles is prepared and the pure ruthenium as a lithium‐ion battery anode for complete understanding on anomalous lithium storage reaction mechanism is designed. In particular, the pure metal electrode is intended for eliminating the electrochemical reaction‐derived Li₂O phase accompanied by catalytic Li₂O decomposition and the interfacial lithium storage at Ru/Li₂O phase boundary, and thereby focusing on the ruthenium itself in exploring its electrochemical reactivity. Intriguingly, unusual lithium storage not involving redox reactions with electron transfer but leading to lattice expansion is identified in the ruthenium electrode. Size‐dependent charge redistribution at surface enables additional lithium adsorption to occur on the inactive but more environmentally sensitive nanoparticles, providing innovative insight into dynamic electrode environments in rechargeable lithium chemistry.     

High-Performance Solid Lithium Metal Batteries Enabled by LiF/LiCl/LiIn Hybrid SEI via InCl3-Driven In Situ Polymerization of 1,3-Dioxolane

The use of poly(1,3-dioxolane) (PDOL) electrolyte for lithium batteries has gained attention due to its high ionic conductivity, low cost, and potential for large-scale applications. However, its compatibility with Li metal needs improvement to build a stable solid electrolyte interface (SEI) toward metallic Li anode for practical lithium batteries. To address this concern, this study utilized a simple InCl₃-driven strategy for polymerizing DOL and building a stable LiF/LiCl/LiIn hybrid SEI, confirmed through X-ray photoelectron spectroscopy (XPS) and cryogenic-transmission electron microscopy (Cryo-TEM). Furthermore, density functional theory (DFT) calculations and finite element simulation (FES) verify that the hybrid SEI exhibits not only excellent electron insulating properties but also fast transport properties of Li⁺. Moreover, the interfacial electric field shows an even potential distribution and larger Li⁺ flux, resulting in uniform dendrite-free Li deposition. The use of the LiF/LiCl/LiIn hybrid SEI in Li/Li symmetric batteries shows steady cycling for 2000 h, without experiencing a short circuit. The hybrid SEI also provided excellent rate performance and outstanding cycling stability in LiFePO₄/Li batteries, with a high specific capacity of 123.5 mAh g⁻¹ at 10 C rate. This study contributes to the design of high-performance solid lithium metal batteries utilizing PDOL electrolytes.     

构建亲锂铜基3D集流体实现金属锂的均匀沉积

锂金属负极以其最高的理论比容量(3860 mAh·g ^-1)和最低的电化学电位(-3.04 V (vs SHE))被誉为电池界的“圣杯”。但是锂金属电池的缺点也尤为明显: 充放电过程中锂金属电池容易在负极不均匀沉积从而产生锂枝晶, 锂枝晶的产生会造成固体电解质介面(SEI)膜的持续破裂, 不稳定的SEI膜又会加剧锂枝晶的形成, 进而刺穿隔膜, 导致电池的循环性能下降, 产生安全隐患, 所以采取相应的措施在负极均匀沉积金属锂尤为重要。本研究使用商业化的铜网, 通过碱性溶剂的氧化和空气气氛煅烧, 在铜网表面形成均一的亲锂氧化铜纳米片阵列。铜网的3D结构可以有效减小电流密度, 亲锂的纳米片阵列可以降低锂的沉积过电势, 均匀沉积锂, 有效抑制锂枝晶的产生。在电流密度为3 mA·cm ^-2的半电池测试中, 稳定循环230圈后库伦效率稳定维持在99%以上; 搭配磷酸铁锂(LFP)全电池测试, 在1C(0.17 mA·mg ^-1)条件下可稳定循环300圈, 容量保持率为95%。本研究为锂金属负极3D集流体的设计提供了新思路。     

Nano-carbon coating layer prepared by the thermal evaporation of fullerene C60 for lithium metal anodes in rechargeable lithium batteries

A nano carbon coating layer was prepared by the thermal evaporation of fullerene C60 on the surface of lithium metal anodes for rechargeable lithium batteries. The morphology and structure of the carbon layer was firstly investigated by Raman spectroscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The effects of the nano-carbon coating layer on the electrochemical performance of the lithium electrode were then examined by charge-discharge tests and impedance spectroscopy. Raman spectra of carbon coating layer showed two main peaks (D and G peaks), indicating the amorphous structure of the film. A honey comb-like structure of carbon film was observed by TEM photographs, providing a transport path for the transport of lithium ions at the electrode/electrolyte interface. The carbon coated lithium electrodes exhibited a higher initial coulombic efficiency (91%) and higher specific capacity retention (88%) after the 30th cycle at 0.2 C-rate between 3.4 and 4.5 V. Impedance measurements showed that the charge transfer resistance was significantly reduced after cycle tests for the carbon coated electrodes, revealing that the more stable solid electrolyte (SEI) layer was established on their surface. Based on the experimental results, it suggested that the presence of the nano-carbon coating layer might suppress the dendritic growth on the surface of lithium metal electrodes, as confirmed by the observation of SEM images after cycle tests.     

A 3D and Stable Lithium Anode for High‐Performance Lithium–Iodine Batteries

Lithium metal is considered as the most promising anode material due to its high theoretical specific capacity and the low electrochemical reduction potential. However, severe dendrite problems have to be addressed for fabricating stable and rechargeable batteries (e.g., lithium–iodine batteries). To fabricate a high‐performance lithium–iodine (Li–I₂) battery, a 3D stable lithium metal anode is prepared by loading of molten lithium on carbon cloth doped with nitrogen and phosphorous. Experimental observations and theoretical calculation reveal that the N,P codoping greatly improves the lithiophilicity of the carbon cloth, which not only enables the uniform loading of molten lithium but also facilitates reversible lithium stripping and plating. Dendrites formation can thus be significantly suppressed at a 3D lithium electrode, leading to stable voltage profiles over 600 h at a current density of 3 mA cm^?2. A fuel cell with such an electrode and a lithium–iodine cathode shows impressive long‐term stability with a capacity retention of around 100% over 4000 cycles and enhanced high‐rate capability. These results demonstrate the promising applications of 3D stable lithium metal anodes in next‐generation rechargeable batteries.     

Solid state lithium metal batteries – Issues and challenges at the lithium-solid electrolyte interface

Solid-state Li-ion batteries employing a metallic lithium anode in conjunction with an inorganic solid electrolyte (ISE) are expected to offer superior energy density and cycle life. The realization of these metrics critically hinges on the simultaneous optimization of the ISE and the two electrode/electrolyte interfaces. In this Opinion article, we provide an overview of the materials and interfacial challenges that limit the performance of solid-state lithium metal batteries (SSLMBs). Owing to the importance of the Li/ISE interface, we dedicate a large section of this article to discuss the mechanistic aspects of lithium deposition at the Li/ISE interface. We further discuss a few recently proposed mechanisms that rationalize the growth of lithium through ISEs. We conclude our review with a brief discussion on the anode-free approach for fabricating SSLMBs where metallic lithium is generated in-situ from pre-lithiated cathodes.     

新型液态金属电池正极材料的探索研究

利用液态金属电池储能是近年来发展起来的一种新型电化学储能技术,具有成本低、寿命长等优点,在大型储能领域具有广阔的应用前景。传统单一组分的正极材料面临熔点高、电压低等问题,而合金材料则给液态金属电池正极材料提供了新的可能。本文通过分子动力学方法计算多种适用于液态金属电池正极材料的金属和合金材料(Bi、Sb、Te、Sn、Pb),经过多尺度计算模拟,首先找到了30种二元合金和三元合金,分析这些合金材料的形成能,发现均为负值,理论上说明这30种二元合金和三元合金均可以稳定存在。而后,筛选出具有较低熔点(<500℃)的正极合金,分别是SnSb、HgTl、InBi、PbSb、HgIn、InTe、GaSb、AlSb、CdSnSb2、ZnSb。进一步分析合金正极材料的态密度,选出7种离子传输能力较强的正极合金:PbSb、HgIn、CdSnSb2、ZnSnSb2、InTe、SnSb和SnTl4Te3,模拟计算其以锂为负极情况下的开路电压,结果表明,以SnSb为正极材料时,开路电压可达0.65 V。     

A Single-Ion Conducting Borate Network Polymer as a Viable Quasi-Solid Electrolyte for Lithium Metal Batteries

Lithium-ion batteries have remained a state-of-the-art electrochemical energy storage technology for decades now, but their energy densities are limited by electrode materials and conventional liquid electrolytes can pose significant safety concerns. Lithium metal batteries featuring Li metal anodes, solid polymer electrolytes, and high-voltage cathodes represent promising candidates for next-generation devices exhibiting improved power and safety, but such solid polymer electrolytes generally do not exhibit the required excellent electrochemical properties and thermal stability in tandem. Here, an interpenetrating network polymer with weakly coordinating anion nodes that functions as a high-performing single-ion conducting electrolyte in the presence of minimal plasticizer, with a wide electrochemical stability window, a high room-temperature conductivity of 1.5 × 10⁻⁴ S cm⁻¹, and exceptional selectivity for Li-ion conduction (t_Li+ = 0.95) is reported. Importantly, this material is also flame retardant and highly stable in contact with lithium metal. Significantly, a lithium metal battery prototype containing this quasi-solid electrolyte is shown to outperform a conventional battery featuring a polymer electrolyte.