Single-Ion Conducting Polymer Electrolyte for Superior Sodium-Metal Batteries

Sodium-metal batteries (SMBs) are considered a potential alternative to high-energy lithium-metal batteries (LMBs). However, the high reactivity of metallic sodium towards common liquid organic electrolytes renders such battery technology particularly challenging. Herein, we propose a multi-block single-ion conducting polymer electrolyte (SIPE) doped with ethylene carbonate as suitable electrolyte system for SMBs. This novel SIPE provides a very high ionic conductivity (2.6 mS cm⁻¹) and an electrochemical stability window of about 4.1 V at 40 °C, enabling stable sodium stripping and plating and excellent rate capability of Na||Na₃V₂(PO₄)₃ cells up to 2 C. Remarkably, such cells provide a capacity retention of about 85 % after 1,000 cycles at 0.2 C thanks to the very high Coulombic efficiency (99.9 %), resulting from an excellent interfacial stability towards sodium metal and the Na₃V₂(PO₄)₃ cathode.     

An Ultrathin Inorganic Molecular Crystal Interfacial Layer for Stable Zn Anode

Zn metal anode suffers from dendrite growth and side reactions during cycling, significantly deteriorating the lifespan of aqueous Zn metal batteries. Herein, we introduced an ultrathin and ultra-flat Sb₂O₃ molecular crystal layer to stabilize Zn anode. The in situ optical and atomic force microscopes observations show that such a 10 nm Sb₂O₃ thin layer could ensure uniform under-layer Zn deposition with suppressed tip growth effect, while the traditional WO₃ layer undergoes an uncontrolled up-layer Zn deposition. The superior regulation capability is attributed to the good electronic-blocking ability and low Zn affinity of the molecular crystal layer, free of dangling bonds. Electrochemical tests exhibit Sb₂O₃ layer can significantly improve the cycle life of Zn anode from 72 h to 2800 h, in contrast to the 900 h of much thicker WO₃ even in 100 nm. This research opens up the application of inorganic molecular crystals as the interfacial layer of Zn anode.     

Semi-Metallic Superionic Layers Suppressing Voltage Fading of Li-Rich Layered Oxide Towards Superior-Stable Li-Ion Batteries

Li-rich layered oxides (LRLOs) with greater specific capacity density are constrained by voltage attenuation and inferior rate performance because of irreversible oxygen release, metal dissolving and poor lithium-ion transport capacity. Herein, a simple surface modification is designed to solve the performance degradation and structural collapse of LRLOs. Combining experiments with density functional theory (DFT) calculations, a semi-metallic LiMn₂O₄-like structure (LMO) with spin-polarized conducting electrons, is introduced to the surface of the cathode restrains the activated surficial lattice oxygen ions by its stable oxygen vacancies. Additionally, Ni doping results in a fast-ion conductor Li_0.8Nb_0.96Ni_0.2O₃ structure (LNO) with lowered lithium ions diffusion barrier, which is tightly conjugating to substrate and synergistically reinforces the Li diffusion path through the cathode-electrolyte interphase. Moreover, Mn dissolution is successfully relieved due to the decrease in Mn concentration in the coating layers. As a result, the modified material (LRLO@LMO@LNO) exhibits an ultra-high discharge capacity of 120.4 mAh g⁻¹ even at 10 C with a very small discharge voltage attenuation of 313 mV after 600 cycles (0.52 mV per cycle) at 1 C. Undoubtedly, this method discloses a simple and effective approach to promote the practical utilization of high-energy-density.     

几种不同进口“铅矿”的表征及属性分析研究

通过5种申报为“铅矿”的进口含铅物料的分析,发现铅矿伪报的现象时有发生,这些物料从外观上、铅含量上很难确认其真实属性,实验通过分析样品的理化特征,比对研究和文献查找的方法,分析进口含铅物料来源,进而获得属性判定的方法。其方法主要包括以下5个步骤:(1 )观察样品的外观性状,包括形状、粒度、颜色、手感、气味、磁性等特征;(2)测试样品的理化性质,包括元素组成、物相组成、微观形貌以及酸碱性等其他可能必要的信息;(3)对比研究所属申报品名的样品特征,即对铅矿样品进行比对研究;(4) 比对查证文献资料等,根据获得的样品的相关检测数据和铅矿信息,查阅相关的文献资料,对样品可能产生的来源进行查证分析; (5)确立样品的来源,从而确认样品的属性。     

基于特征分解谱估计的蓄电池内阻检测方法

针对目前在蓄电池内阻检测中被广泛采用的锁相放大法存在硬件电路复杂、成本较高、操作复杂等问题,提出采用特征分解谱估计的方法来替代蓄电池内阻检测中的锁相放大环节,以软件计算的方法替代硬件电路,从而降低硬件成本及操作难度。通过对特征分解谱估计的原理分析以及对运用特征分解谱估计方法进行蓄电池内阻测量时的关键步骤,即电压信号的提取与幅值检测进行仿真,仿真表明特征分解谱估计方法在高功率噪声背景下仍有较高的频率分辨力,幅值测量结果在50dB高斯白噪声背景下测量误差约为2%,而在20dB非高斯白噪声背景下测量误差约为3%。分析表明基于特征分解谱估计的蓄电池内阻检测方法在较高功率非高斯噪声背景下具有良好的检测效果,可以作为微弱信号检测的软件实现方法以替代锁相放大环节。     

Atomically Dispersed FeN2P2 Motif with High Activity and Stability for Oxygen Reduction Reaction Over the Entire pH Range

The past decade has witnessed the great potential of Fe-based single-atom electrocatalysis in catalyzing oxygen reduction reaction (ORR). However, it remains a grand challenge to substantially improve their intrinsic activity and long-term stability in acidic electrolytes. Herein, we report a facile chemical vapor deposition strategy, by which high-density Fe atoms (3.97 wt%) are coordinated with square-planar para-positioned nitrogen and phosphorus atoms in a hierarchical carbon framework. The as-crafted atomically dispersed Fe catalyst (denoted Fe-SA/PNC) manifests an outstanding activity towards ORR over the entire pH range. Specifically, the half-wave potential of 0.92 V, 0.83 V, and 0.86 V vs. reversible hydrogen electrode (RHE) are attained in alkaline, neutral, and acidic electrolytes, respectively, representing the high performance among reported catalysts to date. Furthermore, after 30,000 durability cycles, the Fe-SA/PNC remains to be stable with no visible performance decay when tested in 0.1 M KOH and 0.5 M H₂SO₄, and only a minor negative shift of 40 mV detected in 0.1 M HClO₄, significantly outperforming commercial Pt/C counterpart. The coordination motif of Fe-SA/PNC is validated by density functional theory (DFT) calculations. This work provides atomic-level insight into improving the activity and stability of non-noble metal ORR catalysts, opening up an avenue to craft the desired single-atom electrocatalysts.     

A binderless,covalently bulk modified electrochemical sensor: Application to simultaneous determination of lead and cadmium at trace level

A new type of covalent binderless bulk modified electrode has been fabricated and used in the simultaneous determination of lead and cadmium ions at nanomolar level. The modification of graphitic carbon with 4-amino salicylic acid was carried out under microwave irradiation through the amide bond formation. The electrochemical behavior of the fabricated electrode has been carried out to decipher the interacting ability of the functional moieties present on the modifier molecules toward the simultaneous determination of Pb²⁺ and Cd²⁺ ions using cyclic and differential pulse anodic stripping voltammetry. The possible mode of interaction of functional groups with metal ions is proposed based on the pKa values of the modifier functionalities present on the surface of graphitic carbon particles. The analytical utility of the proposed sensor has been validated by measuring the lead and cadmium content from pretreated waste water samples of lead acid batteries.     

Electrochemistry of Klason Lignin

The possibility of the use of Klason lignin extracted from sunflower husks as a cathode-active material for primary lithium battery has been demonstrated for the first time. The chemical composition, morphological and physical features were characterized by X-ray energy dispersive spectroscopy, impedance spectroscopy, scanning electron microscopy, and infrared spectroscopy. Electrochemical behavior of Klason lignin vs. Li/Li⁺ was studied by galvanostatic discharge and cyclic voltammetry. The reaction mechanism in electrochemical system was discussed. The maximum specific capacity of Klason lignin amounted to 380 mAh g^–1 at a current density of 25 mA g^–1.     

超声衰减谱测量电池浆料的粒度分布

电池浆料中颗粒状活性物质的粒度大小和分散均匀性对电池的内阻、 电压、 局部表面电流和总极化程度等性能有直接影响, 实现对其的在线实时测量对电池的质量控制具有重要意义. 基于电池浆料的高固含量、 高黏度和低透光性的特点, 本文利用超声衰减谱的方式测量了其粒度分布(PSD). 应用于电池浆料的粒度分布测量的最大难点是其利用超声衰减谱法预测粒度分布的模型需要难以获得的分散相和连续相的物性参数. 本文采用主成分分析(PCA)结合误差反向传播(BP)神经网络建立预测模型解决了超声衰减谱法的难点, 并引入遗传算法(GA)优化BP神经网络的初始阈值和权值. 通过以LiCoO₂为活性物质的电池浆料进行了验证, 结果表明, PCA-GA-BP神经网络能够有效对不同固含量电池浆料的粒度分布进行预测, 预测值与真实值的峰形重合度高, 峰高偏差小, 两者的均方误差为0.1358, 拟合度(R²)为0.9816, 说明超声衰减谱法可作为测量电池浆料粒度分布的重要方式.     

二次电池研究进展

能源的存储和利用是当今科学和技术发展中的重大课题之一,尤其是作为高效的电能/化学能转化装置的二次电池相关技术一直是科学家研究的热点领域。在此背景下,本文较为系统地介绍目前二次电池的重要研究进展,将从二次电池的发展历史引入,再到其相关的基础理论知识的介绍。随后较为详细地讨论当前不同体系的二次电池及相关应的关键材料的研究进展,涉及到锂离子电池、钠离子电池、钾离子电池、镁离子电池、锌离子电池、钙离子电池、铝离子电池、氟离子电池、氯离子电池、双离子电池、锂-硫(硒)电池、钠-硫(硒)电池、钾-硫(硒)电池、多价金属-硫基电池、锂-氧电池、钠-氧电池、钾-氧电池、多价金属-氧气电池、锂-溴(碘)电池、水系金属离子电池、光辅助电池、柔性电池、有机电池、金属-二氧化碳电池等。此外,也介绍了电池研究中常见的电极反应过程表征技术,包括冷冻电镜、透射电镜、同步辐射、原位谱学表征、磁性表征等。本文将有助于研究人员对二次电池进行全面系统的了解与把握,并为之后二次电池的研究提供很好的指导作用。