用分离电池技术研究稀土对铝合金的缓蚀机制

提出应用分离电池技术研究稀土对铝合金的缓蚀机制的方法。首先分析了分离电池技术的原理与实验方法；然后通过利用分离电池技术测定因溶液中氧含量改变和添加CeCl3导致两电极之间的净电流的变化，研究了CeCl3对LC4强超铝合金在0．1mol·L^-1。NaCl溶液中腐蚀行为的影响；同时利用该技术研究了pH值、CeCl3溶液以及作用时间等条件变化对缓蚀过程的影响；最后应用扫描电子显微镜（SEM）和X射线能量散射谱（EDS）表征电极表面的形貌特征，结合其他电化学技术如电位-时间曲线、极化曲线等手段，

IEC 60335-1第6.0版对电池供电器具的要求浅析

随着电池的能量密度持续提升,电池续航时间延长,由电池故障引起的家电起火、爆炸的事件也越来越多,对相关用户和企业造成了巨大损失。新版IEC 60335-1:2020标准中也增加了关于电池供电器具的相关要求。现对IEC 60335-1标准6.0版附录B的适用范围、标志和说明、发热、非正常工作、结构等主要条款和要求进行介绍和解读。

铈盐对铝合金的缓蚀机理研究

应用分离电解池(the split cell)技术将阴阳极分离,通过测定因溶液中氧含量改变和添加CeCl3导致两电极之间的净电流的变化,研究了CeCl3对B95超强铝合金在0.1 mol/L NaCl溶液中腐蚀行为的影响,并用扫描电子显微镜(SEM)和X射线能量散射谱(EDS)表征电极表面的形貌特征,结合其它电化学技术如电位-时间曲线、极化曲线等手段,对Ce盐缓蚀机理作了深入探讨.结果表明,经Ce盐处理的B95超强铝合金表面可形成一层不均匀分布的转化膜,成膜动力学包括铝合金的溶解及随后的成膜两个过程;铝合金Ce化学转化膜主要由Ce、O、Al组成;3.5%NaCl溶液全浸试验表明添加CeCl3后腐蚀率可降低数百倍,铝合金的耐蚀性能大大提高,CeCl3表现为一种优良的铝合金缓蚀成膜剂.

The potassium storage performance of carbon nanosheets derived from heavy oils

As by-products of petroleum refining,heavy oils are characterized by a high carbon content,low cost and great variability,making them competitive precursors for the anodes of potassium ion batteries(PIBs).However,the relationship between heavy oil composition and potassium storage performance remains unclear.Using heavy oils containing distinct chemical groups as the carbon source,namely fluid catalytic cracking slurry(FCCS),petroleum asphalt(PA)and deoiled asphalt(DOA),three carbon nanosheets(CNS)were prepared through a molten salt method,and used as the anodes for PIBs.The composition of the heavy oil determines the lamellar thicknesses,sp^(3)-C/sp^(2)-C ratio and defect concentration,thereby affecting the potassium storage performance.The high content of aromatic hydrocarbons and moderate amount of heavy component moieties in FCCS produce carbon nanosheets(CNS-FCCS)that have a smaller layer thickness,larger interlayer spacing(0.372 nm),and increased number of folds than in CNS derived from the other three precursors.These features give it faster charge/ion transfer,more potassium storage sites and better reaction kinetics.CNS-FCCS has a remarkable K^(+)storage capacity(248.7 mAh g^(-1) after 100 cycles at 0.1 A g^(-1)),long cycle lifespan(190.8 mAh g^(-1) after 800 cycles at 1.0 A g^(-1))and excellent rate capability,ranking it among the best materials for this application.This work sheds light on the influence of heavy oil composition on carbon structure and electrochemical performance,and provides guidance for the design and development of advanced heavy oil-derived carbon electrodes for PIBs.

Improvement of ionic conductivity of solid polymer electrolyte based on Cu-Al bimetallic metal-organic framework fabricated through molecular grafting

A composite solid electrolyte comprising a Cu-Al bimetallic metal-organic framework(CAB),lithium salt(LiTFSI)and polyethylene oxide(PEO)was fabricated through molecular grafting to enhance the ionic conductivity of the PEO-based electrolytes.Experimental and molecular dynamics simulation results indicated that the electrolyte with 10 wt.%CAB(PL-CAB-10%)exhibits high ionic conductivity(8.42×10~(-4)S/cm at 60℃),high Li+transference number(0.46),wide electrochemical window(4.91 V),good thermal stability,and outstanding mechanical properties.Furthermore,PL-CAB-10%exhibits excellent cycle stability in both Li-Li symmetric battery and Li/PL-CAB-10%/LiFePO4 asymmetric battery setups.These enhanced performances are primarily attributable to the introduction of the versatile CAB.The abundant metal sites in CAB can react with TFSI~-and PEO through Lewis acid-base interactions,promoting LiTFSI dissociation and improving ionic conductivity.Additionally,regular pores in CAB provide uniformly distributed sites for cation plating during cycling.

Influence of CO2 on Oxygen Surface Exchange Kinetics of Mixed- Conducting Ba0.5 Sr0.5 Co0.8 Feo.2O3_δ Oxide

The poisoning effect of CO2 on the oxygen surface exchange kinetics of BSCF （Ba0.5 Sr0.5 Co0.8 Feo.2O3_δ） is investigated with a novel pulse isotopic exchange technique. The surface exchange rate of BSCF severely decreases after in situ exposure to CO2, which is ascribed to carbonate formation on the material surface. The detrimental effect of CO2 starts at a low temperature of 375 ℃ and concentration as low as 1%, and becomes more pro- nounced at higher temperatures. Degradation of the surface exchange kinetics is associated with a rapid loss of oxygen permeation performance of BSCF in CO2.

Working Condition Real-Time Monitoring Model of Lithium Ion Batteries Based on Distributed Parameter System and Single Particle Model

Lithium ion batteries are complicated distributed parameter systems that can be described preferably by partial differential equations and a field theory. To reduce the solution difficulty and the calculation amount, if a distributed parameter system is described by ordinary differential equations （ODE） during the analysis and the design of distributed parameter system, the reliability of the system description will be reduced, and the systemic errors will be introduced. Studies on working condition real-time monitoring can improve the security because the rechargeable LIBs are widely used in many electronic systems and electromechanical equipment. Single particle model （SPM） is the simplification of LIB under some approximations, and can estimate the working parameters of a LIB at the faster simulation speed. A LIB modelling algorithm based on PDEs and SPM is proposed to monitor the working condition of LIBs in real time. Although the lithium ion concentration is an unmeasurable distributed parameter in the anode of LIB, the working condition monitoring model can track the real time lithium ion concentration in the anode of LIB, and calculate the residual which is the difference between the ideal data and the measured data. A fault alarm can be triggered when the residual is beyond the preset threshold. A simulation example verifies that the effectiveness and the accuracy of the working condition real-time monitoring model of LIB based on PDEs and SPM.

Selective recovery of lithium from spent lithium iron phosphate batteries using oxidation pressure sulfuric acid leaching system

Oxidation pressure leaching was proposed to selectively dissolve Li from spent LiFePO_(4) batteries in a stoichiometric sulfuric acid solution.Using O_(2) as an oxidant and stoichiometric sulfuric acid as leaching agent,above 97% of Li was leached into the solution,whereas more than 99% of Fe remained in the leaching residue,enabling a relatively low cost for one-step separation of Li and Fe.And then,by adjusting the pH of leachate,above 95% of Li was recovered in the form of the Li_(3)PO_(4) product through iron removal and chemical precipitation of phosphate.

Optimizing pyrolysis of resin carbon for anode of lithium ion batteries

Pyrolytic resin carbon anode for lithoum ion batteries was prepared from thermosetting phenolic resin. Pyrolysis of the primary phenolic resin and the dewatered one was studied by thermal gravimetric analysis. Structures and characteristics of the carbon materials were determined by X-ray diffraction, Brunauer-Emmer-Teller surface area analysis and electrochemical measurements. With the increase of pyrolyzing temperature and soaking time, the resin carbon material has larger crystallite sizes of L_c and L_a, lower specific surface area, smaller irreversible capacity and higher initial coulombic efficiency. The pyrolyzing temperature and soaking time are optimized to be 1050℃ and 2h. The resin carbon anode obtained under the optimum conditions shows good electrochemical performances with reversible capacity of 387mA·h/g and initial coulombic efficiency of 69.1%.

支持并促进电动汽车产业健康发展

以纯电动汽车为代表的新能源汽车产业是中国战略性新兴产业,但是,纯电动汽车产业目前遇到了很大的发展瓶颈,究其原因在于最初的技术路径选择出现了问题,笔者在调研中惊喜地发现一种车电分离、电池标准化并共享的新型技术方案,能够彻底解决制约整个产业发展的瓶颈问题.

Thermal Modeling and Cooling Analysis of High-power Lithium Ion Cells

The heat generation model and three-dimensional computational fluid dynamics model for lithium ion cells were established with boundary conditions defined.In order to provide a better insight about the behaviors of high-power lithium ion cells under realistic discharge conditions,the temperature difference of the cells and an active thermal management system with a pure air-cooling mode were analyzed and predicted with the factors affecting the unevenness of temperature field discussed.The results show a significant effect of the cooling flow rate on the temperature rise of the cells for all discharge rates.Average surface temperatures are relatively uniform at lower discharge rate that makes it easier to control the temperature of the pack.Cell temperatures are expected to rise significantly toward the end of discharge and they show non-uniformity at higher discharge rates.Adequate air flow rate of active cooling is required at high discharge rate and high ambient temperature for practical pack thermal management system.

Estimating the thickness of diffusive solid electrolyte interface

electrolyte. The properties of lithium-ion (Li-ion) battery, such as cycle life, irreversible capacity loss, self-discharge rate, electrode corrosion and safety are usually ascribed to the quality of the SEI, which are highly dependent on the thickness. Thus, understanding the formation mechanism and the SEI thickness is of prime interest. First, we apply dimensional analysis to obtain an explicit relation between the thickness and the number density in this study. Then the SEI thickness in the initial charge-discharge cycle is analyzed and estimated for the first time using the Cahn-Hilliard phase-field model. In addition, the SEI thickness by molecular dynamics simulation validates the theoretical results. It has been shown that the established model and the simulation in this paper estimate the SEI thickness concisely within order-of-magnitude of nanometers. Our results may help in evaluating the performance of SEI and assist the future design of Li-ion battery.

High-performance of sodium carboxylate-derived materials for electrochemical energy storage

Four types of sustainable sodium carboxylate- derived materials are investigated as novel electrodes with high performance for lithium-ion batteries. Benefiting from the porous morphology provided by their intermolecular in- teractions, increasing capacity, excellent cycle stability and superior rate performance are observed for the sodium car- boxylate-derived materials. The sodium oxalate （SO） electro- des displayed an increasing discharging capacity at a current density of 50 mA g-1 with maximum values of 242.9 mA h g-1 for SO-631 and 373.9 mA h g-1 for SO-541 during the 100th cycle. In addition, the SO-541, SC-541 （sodium citrate）, ST- 541 （sodium tartrate） and SP-541 （sodium pyromellitate） electrode materials displayed high initial capacities of 619.6-392.3, 403.7 and 278.1 mA h g-1, respectively, with capacity retentions of 179%, 148%, 173% and 108%, respectively, after 200 cycles at 50 mA g-1. Even at a high current density of 2,000 mA g-1, the capacities remain 157.6, 131.3, 146.6 and 137.0mAhg-1, respectively. With these superior electro- chemical properties, the sodium carboxylate-derived materials could be considered as promising organic electrode materials for large-scale sustainable lithium-ion batteries.