Flexible path planning-based reconfiguration strategy for maximum capacity utilization of battery pack

Maximizing the utilization of lithium-ion battery capacity is an important means to alleviate the range anxiety of electric vehicles.Battery pack inconsistency is the main limiting factor for improving battery pack capacity utilization,and poses major safety hazards to energy storage systems.To solve this problem,a maximum capacity utilization scheme based on a path planning algorithm is proposed.Specifically,the reconfigurable topology proposed is highly flexible and fault-tolerant,enabling battery pack consistency through alternating cell discharge and reducing the increased risk of short circuits due to relay error.The Dijkstra algorithm is used to find the optimal energy path,which can effectively remove faulty cells and find the current path with the best consistency of the battery pack and the lowest relay loss.Finally,the effectiveness of the scheme is verified by hardware-in-the-loop experiments,and the experimental results show that the state-of-charge SOC consistency of the battery pack at the end of discharge is increased by 34.18%,the relay energy loss is reduced by 0.16%,and the fault unit is effectively isolated.

Discharge performance of Mg-Al-Pb-La anode for Mg-air battery

b The discharge performance of Mg-Al-Pb-La anode was investigated by electrochemical techniques and compared withthat of Mg-Al-Pb alloy. The results indicate that the Mg-Al-Pb-La anode provides enhanced corrosion resistance at open circlepotential, and exhibits better discharge activity than the Mg-Al-Pb alloy. The utilization efficiency of Mg-Al-Pb-La anode ishigher than that of commercial Mg-Al-Zn （AZ） and Mg-Al-Mn （AM） alloys. A single Mg-air battery with Mg-Al-Pb-La alloy asthe anode and air as the cathode has an average discharge potential of 1.295 V and a discharge capacity of 1370 mA·h/g duringdischarge at 10 mA/cm2, which is higher than that of batteries using Mg-Li anodes. The enhancement in discharge performance ofthe Mg-Al-Pb-La anode is caused by its modified microstructure, which reduces the self-corrosion and accelerates the spalling ofoxidation products during battery discharge. Furthermore, the dissolution mechanism of Mg-Al-Pb-La anode during the dischargeprocess was analyzed.

China's Industrial Capacity Utilization:Sectoral Comparison,Regional Differences and Determinants

Using provincial-level data, this paper has estimated capacity utilization, technical efficiency and equipment utilization for China's industrial sectors, conducted a comparative analysis of capacity utilization across various sectors, provinces, municipalities and autonomous regions, and discussed the determinants of capacity utilization. We have reached the following conclusions:(1) China's average industrial capacity utilization stood at 69.3% between 2001 and 2011, rising for most of the time before 2008 and generally declining afterwards;(2) among the two sources of capacity utilization, equipment utilization is lower than technical efficiency and constitutes a major factor affecting capacity utilization, yet technical efficiency has demonstrated a significant trend of decline in recent years;(3) at the industry level, industrial capacity utilization is generally high for light industries such as textiles while generally low for mining, public utilities and heavy industries in manufacturing;(4) at the regional level, capacity utilization, technical efficiency and equipment utilization are much higher in the eastern region than in the other regions, where the levels are relatively close to each other;(5) economic growth and the level of market-based operation have a significant positive correlation with capacity utilization, while industry capital intensity, the share of output value from SOEs and local government investment intensity have a significant negative correlation with capacity utilization.

石油焦锂离子电池负极材料电化学性能研究

负极材料是决定锂离子电池性能的关键因素,人造石墨是重要的锂离子电池负极材料。石油焦的热膨胀系数低,空隙度低,灰分、硫、金属元素含量低,导电率高,易石墨化。此次研究选择3种普通石油焦,并通过石墨化制备人造石墨。对3种石油焦原样和石墨化样品进行分析表征,比较其各种性能,研究石油焦石墨化后的变化,并通过电化学分析验证石油焦石墨化后其性能是否达到商用锂电池负极材料水平。实验结果表明:在2750℃石墨化处理后,相较于原石油焦样品,3种石墨化样品结构重排,拥有更明显的规整层状结构;含碳量提升,其他例如氢、氧等杂元素和金属元素含量下降;均显现出较低的电极电位和稳定的充放电平台,首次库伦效率分别为85.00%、78.20%、82.96%。经过150次循环后,比容量分别保持在273.00、259.00、226.20 mAh/g,库伦效率接近100%,是锂离子电池负极材料的潜在前驱体。

Microstructures and electrochemical corrosion properties of Mg-Al-Pb and Mg-Al-Pb-Ce anode materials

Mg-Al-Pb alloy is a good candidate for the anode material of magnesium seawater battery. For improving the low current utilization efficiency of Mg-Al-Pb alloy, the influence of Ce on the microstructures and electrochemical corrosion properties in a 3.5% NaCl solution was investigated using scanning electron microscope and electrochemical measurements. The results indicate that Ce refines the grain structure of Mg-Al-Pb alloy. The formation of strip Al11Ce3 second phase promotes the uniform distribution of Mg17Al12 phase in Mg-Al-Pb-Ce alloy. The addition of cerium accelerates the discharge activity of Mg-Al-Pb alloy. Due to a large number of cathodic Al11Ce3 and MglyAla2 phases, Ce promotes the micro-galvanic corrosion and leads to larger corrosion current density and hydrogen evolution rate in Mg-Al-Pb-Ce alloy than those in Mg-Al-Pb alloy. However, Mg-Al-Pb alloy expresses smaller utilization efficiency than Mg-Al-Pb-Ce alloy because of grain detachment.

Access to advanced sodium-ion batteries by presodiation:Principles and applications

Sodium-ion batteries(SIBs)are expected to offer affordability and high energy density for large-scale energy storage system.However,the commercial application of SIBs is hurdled by low initial coulombic efficiency(ICE),continuous Na loss during long-term operation,and low sodium-content of cathode materials.In this scenario,presodiation strategy by introducing an external sodium reservoir has been rationally proposed,which could supplement additional sodium ions into the system and thereby markedly improve both the cycling performance and energy density of SIBs.In this review,the significance of presodiation is initially introduced,followed by comprehensive interpretation on technological properties,underlying principles,and associated approaches,as well as our perspectives on present inferiorities and future research directions.Overall,this contribution outlines a distinct pathway towards the presodiation methodology,of significance but still in its nascent phase,which may inspire the targeted guidelines to explore new chemistry in this field.

基于博弈论的风光氢能源系统容量优化

目前风光氢能源系统中的能源利用率较低,传统的容量优化根据电解槽固定制氢效率进行建模且仅考虑了系统中存在1个运营商的情况,没有考虑到不同运营商之间的竞争与合作、电解槽工作时制氢效率的变化情况和待机启动成本,导致容量优化结果不理想。为解决上述问题,首先将有机朗肯循环与燃料电池相结合,用于回收余热;通过分析电解槽制氢效率的影响因素构建动态制氢效率数学模型,并引入二进制变量,用于描述电解槽的待机启动成本;采用基于博弈论的容量优化方法,以全年收益最大为目标采用麻雀搜索算法求解博弈的纳什均衡。仿真结果表明:添加余热利用后能源系统的总收益增加了4%;考虑动态制氢效率和待机启动成本后的质子交换膜电解槽容量减少了26.1%;氢储发电站的收益减少了55.3%;风光氢三方组成大联盟时联盟最稳定,且收益最大、容量配置最合理。

长江干线港口岸线资源利用效率研究

长江干线港口岸线利用效率作为重要的岸线资源规划和利用管理指标,目前缺少明确科学的统一定义。结合长江干线分区段航道特点以及大量现状码头设计和实际生产运营数据调查,对码头设计通过能力规范公式参数取值进行合理修正,测算提出长江干线分区域、分货类、分吨级码头泊位核算通过能力,提出单位岸线核算通过能力这一概念作为单位岸线利用效率量化标准。研究结论可为长江干线港口规划、岸线管理和码头设计工作提供重要技术指标参考。

整体化全钒氧化还原液流电池电堆的开发

为提高全钒液流电池电堆充放电电流密度,开发大功率电堆,通过热熔焊、激光焊接等方式,将双极板、电极和液流框焊接为整体,组装成整体化液流电池电堆。与传统电堆相比,整体化液流电池电堆欧姆内阻由20.2 mΩ降为12.1 mΩ,这主要是由于整体化液流电池电堆采用焊接方式,降低了电极与双极板的接触内阻。在125 mA/cm^(2)电流密度下,整体化液流电池电堆的电压效率为82.8%,比传统电堆电压效率高2.5个百分点;当电流密度为200 mA/cm^(2)时,整体化液流电池电堆的能量效率仍大于75%。当电解液流速超过0.95 m^(3)/h时,电堆能量效率基本不再变化,但放电容量即电解液利用率会进一步提高;当放电截止电压由10.0 V优化为10.5 V时,在200 mA/cm^(2)的电流密度下,整体化电堆的电压效率由78.4%提高到80.0%,电解液利用率基本无变化。

无钴富锂锰基正极材料Li_(1.2)Ni_(0.2)Mn_(0.6)O_(2)的表面改性及电化学性能研究

无钴富锂锰基正极材料Li_(1.2)Ni_(0.2)Mn_(0.6)O_(2)因高比容量、低成本等优点备受关注,是极具潜力的下一代锂离子电池正极材料。然而,Li_(1.2)Ni_(0.2)Mn_(0.6)O_(2)材料存在首次库伦效率低、倍率性能差及容量衰减等问题,限制了其进一步发展。为解决此问题,采用柠檬酸溶液表面处理结合再重新煅烧方法,通过在其表面包覆一层尖晶石相,对Li_(1.2)Ni_(0.2)Mn_(0.6)O_(2)开展了表面改性研究,并对改性前后样品进行物理表征和电化学测试分析。结果表明,改性前后的Li_(1.2)Ni_(0.2)Mn_(0.6)O_(2)正极材料,形貌基本一致,均为尺寸100—400 nm的不规则颗粒,改性后的粉末颗粒边缘略有不平整。使用柠檬酸溶液表面处理后,Li_(1.2)Ni_(0.2)Mn_(0.6)O_(2)材料形成了内部为层状相、表面为尖晶石相的结构。尖晶石相的存在不仅为锂离子扩散提供了三维离子扩散通道、提高倍率性能,还可充当正极材料表面与电解液间的保护层,提高首次库伦效率,改善循环性能。改性后的Li_(1.2)Ni_(0.2)Mn_(0.6)O_(2)的首次库伦效率为92.4%,可逆比容量为292 mAh·g^(-1),与改性前相比分别提高了13.8%和22 mAh·g^(-1),并且在不同倍率下的可逆比容量和长循环容量保持率均有明显提升,表明其具有更好的倍率性能和更优的循环稳定性能。本研究提出了一种无钴富锂锰基正极材料表面改性方法,该改性方法操作简单、效果明显,可应用于不同组分的富锂正极材料,为富锂锰基正极材料的进一步发展提供了新的思路。

工业智能化对企业产能利用率的影响研究——基于制造业上市公司的经验证据

数字技术的快速发展缓解了制造业的生产压力。为了证明工业智能化能否解决企业的产能过剩问题,本文利用2011—2019年沪深A股上市的制造业企业数据,研究工业智能化对产能利用率的影响。研究结果表明,工业智能化可以显著提高企业的产能利用率,通过利用“WinGo相似词数据库”完善工业智能化指标衡量范围,依然证实这一结论。工业智能化可以通过提高资源配置效率、增加人力资本要素的投入和增加企业出口需求三个机制渠道来促进企业的产能利用率的提升,在非国有企业、西部地区、非高新技术企业和技术密集型企业中影响更大。

锂离子电池硅基负极预锂化技术的研究进展

硅基负极具有高理论容量、高安全性、环境友好性等优点,因此被认为是有潜力的新型负极材料。硅材料在首次充放电过程中会生成不可逆的硅酸盐,导致首次库伦效率降低、循环过程中体积膨胀与电解液的严重副反应,进而导致活性锂损失,严重阻碍了硅极负极的工业化进程。预锂化可以补偿初始活性锂损失来提升首效。总结了近年来硅基负极预锂化方法的研究进展以及各种预锂化技术的优缺点,并对其应用前景进行了展望。

基于DELMIA的铅蓄电池生产物流仿真技术研究

针对铅蓄电池产品离散型生产的工序间产能匹配、工艺物流等问题,基于DELMIA三维仿真技术进行物流仿真研究。通过铅蓄电池全产线设备三维建模、物流仿真,对工艺规划设计方案、各工序的生产节拍、设备利用率等进行仿真分析,验证铅蓄电池精益生产工艺流程再造的合理性,达到优化工序间的物流,平衡设备配置和提升设备使用效率,减少人员配置的目标。

Si/C复合锂离子电池负极材料的制备及其性能

从电池性能的角度出发,合理设计电池负极材料是必要的,为此提出Si/C复合锂离子电池负极材料的制备及电化学性能分析研究。准备实验材料和仪器后,分别按照Si:石墨为1:9、2:8、3:7和4:6的比例准备混合料,按照料液比1:4加入无水乙醇作为球磨介质,在球磨机中进行球磨处理,干燥后得到Si含量分别为10%、20%、30%和40%的复合材料;按照质量比为90:5:2:3的比例活性物质(Si/C复合材料)、导电剂碳黑、分散剂乙二醇和粘结剂PVDF配置浆料,涂抹于锂箔表面,经热压成型机对极片进行压实处理,得到Si/C复合锂离子电池负极。在采用电池测试系统在100 mA/g下对硅含量分别为10%、20%、30%和40%的复合材料电极电化学性质进行测试,得出结论Si/C复合锂离子电池负极材料的放电容量受硅含量影响明显,并且不存在直接的线性相关关系;硅含量也会影响Si/C复合锂离子电池负极材料的库伦效率,过高或高低都会导致库伦效率下降。

连涂极板电池化成效率影响因素的探究

对比分析了连续涂板工艺中引入花辊和平辊、装配压力大小及不同涂板纸对连涂极板电池化成效率的影响。花辊和平辊在涂板过程中对极板压力的大小直接影响着极板的孔率,从而影响着极板的充电接受能力。花辊、平辊轻压相比于重压对极板的充电接受能力较好。装配压力在45~55 kPa时电池的存酸量、初始容量等电池指标较好。涂板纸的材质、工艺不同带来涂板纸透气度等参数的不同。涂板纸厚度的选用和覆膜方式不同也给极板的化成效率带来差异。经验证,极板双面覆膜且透气度指标高的涂板纸有益于电池性能。

新能源汽车动力电池发展现状及趋势分析

近年来,新能源汽车的蓬勃发展带动了动力电池产业的壮大,而动力电池的容量、性能、成本及寿命等影响着新能源汽车产业的发展前景和格局。综述了动力电池的市场产量装机量情况、产业分布,分析三代锂离子电池技术的发展及其优缺点、退役动力电池的梯次利用,分别阐述当前动力电池急需解决的安全隐患、里程焦虑、回收利用体系不健全等问题,提出未来技术发展方向和对上下游产业链发展的展望。

惠民县水资源利用现状及改进措施

为分析惠民县水资源利用存在的问题,并有针对性地提出改进措施,广泛收集该县水资源量、用水指标、需水量等基础数据,总结惠民县水资源承载力概况。通过分析发现该县在水资源利用上存在用水结构不合理、用水效率低、机制体制不健全等问题,结合惠民县实际,提出建议措施。

产能利用率与全要素生产率提升——来自制造业上市企业的证据

提升全要素生产率是实现经济高质量发展的关键。本文基于中国2007—2019年的制造业上市企业公开财务数据,利用成本函数法测算微观企业及其所在行业的产能利用率,并进一步探讨企业产能利用率与全要素生产率经济关联。回归结果显示,中国制造业上市企业中两项指标之间存在显著的正向因果关系,产能利用率的改善有助于企业全要素生产率的提升,稳健性检验结果同样支持这一结论。进一步的分析结果显示,对于企业产能利用率而言存在门限值,使得这一正向关系仅在高于门限值时成立。本文从新的角度说明化解产能过剩相关举措的重要意义。政府应继续监测重点行业产能利用率水平,逐步完善市场调节机制,以从源头上减少大规模产能过剩形成的可能性,促进全要素生产率提高。

考虑动力电池梯次利用的充电站容量优化配置

为提高电动汽车充电站储能系统稳定性、安全性和经济性,提出一种考虑动力电池梯次利用的充电站光储容量优化配置方法。首先,针对退役动力电池考虑了电池充放电深度和循环次数对使用寿命的影响,建立了退役动力电池容量衰减和寿命损耗模型,基于容量衰减和寿命损耗模型建立退役动力电池荷电状态(state of charge,SOC)与健康状态(state of health,SOH)耦合关系评价模型;其次,在SOC与SOH耦合关系评价模型的基础上,以充电站年净收益最优为目标函数建立充电站容量优化配置模型;最后,在满足一定能量交换策略的前提下,以某地区光伏储能电站为例对模型进行求解。通过算例分析得出:基于退役电池SOC与SOH耦合关系评价模型进行梯次利用的储能容量优化配置能使整个储能系统的功率峰值降低,且相较于无评价模型系统的功率更加平滑,有利于延长储能系统的寿命周期,提高了系统的稳定性和经济性。

钠离子电池预钠化技术研究进展

介绍了钠离子电池预钠化技术的研究进展。叙述了首圈循环效率低的原因,并综述了最新正负极预钠化技术的发展情况,总结了不同类别预钠化技术的优势和不足,对预钠化技术的发展趋势进行了评述。