Mitigating self-discharge of carbon-based electrochemical capacitors by modifying their electric-double layer to maximize energy efficiency

Self-discharge is a significant issue in electric double layer energy storage, which leads to a rapid voltage drop and low energy efficiency. Here, we attempt to solve this problem by changing the structure of the electric double layer into a de-solvated state, by constructing a nano-scale and ion-conductive solid electrolyte layer on the surface of a carbon electrode. The ion concentration gradient and potential field that drive the self-discharge are greatly restricted inside this electric double layer. Based on this understanding, a high-efficiency graphene-based lithium ion capacitor was built up, in which the self-discharge rate is reduced by 50% and the energy efficiency is doubled. The capacitor also has a high energy density, high power output and long life, and shows promise for practical applications.

Influence of Four Factors on Discharge Capacity and Self-Discharge Rate of Iron Electrode

Ni-Fe rechargeable batteries possess the advantages of long cycle life, high theoretical specific energy, abundant raw material, low price and environmental friendship. It has a wide applied perspective. The advantages, disadvantages and preparation methods of iron electrodes were summarized. The influence of four factors on discharge capacity and self-discharge rate of iron electrode were discussed by means of orthogonal experiments, galvanostatic charges and discharges. The influences of graphite on the discharge capacity and self-discharge rate of iron electrode were the most remarkable, the most unapparent influences on the discharge capacity and self-discharge rate were HPMC (hydroxy propoxy methoxy cellulose) and sodium sulphide, respectively. The aim of the present research was to study the effects of graphite, HPMC and iron powder added in the electrodes, sodium sulphide added in the electrolytes on the discharge capacity and self-discharge rate of iron electrodes. The largest discharge capacity of the iron electrodes was 488.5 mAh/g-Fe at 66.4 mA/g-Fe in the first ten cycles, and the average self-discharge rate was 0.367% per hour.

Self-Discharge in Valve-Regulated Sealed Lead-Acid Batteries

Factors that cause the self-discharge in valve-regulated sealed lead-acid batteries are discussed and measures to inhibit the self-discharge are put forward.

Self-Consistent Model for Pulsed Direct-Current N_2 Glow Discharge

A self-consistent analysis of a pulsed direct-current (DC) N2 glow discharge is presented. The model is based on a numerical solution of the continuity equations for electron and ions coupled with Poisson's equation. The spatial-temporal variations of ionic and electronic densities and electric field are obtained. The electric field structure exhibits all the characteristic regions of a typical glow discharge (the cathode fall, the negative glow, and the positive column). Current-voltage characteristics of the discharge can be obtained from the model. The calculated current-voltage results using a constant secondary electron emission coefficient for the gas pressure 133.32 Pa are in reasonable agreement with experiment.

The Effect of a Multihollow Cathode on the Self-Bias Voltage of Methane RF Discharge Used for a-C:H Deposition

In this work we report the measurement of the self-bias voltage of radiofrequency (RF) capacitevely coupled plasma, with a multihollow cathode and methane precursor, used for amorphous hydrogenated carbon (a- C:H) thin film deposition. The plasma is produced in the incident power and pressure ranges between 20 - 300 W and 10 - 100 mTorr, respectively. It was found that the self-bias voltage Vdc is a linear function of the square root of the incident power WRF. The relationship between the self-bias voltage and gas pressure P is established;this gives an empirical relation for (p/p0)y . From this result, the pressure p0 corresponding to the transition from hollow cathode effect to hollow cathode arc effect is determined.

APPLICATION OF FUZZY CONTROL METHOD WITH SELF-TUNING FACTOR IN JIGGER'S DISCHARGING

Adopting the strategy of fuzzy control with self tuning factor within whole universe of discourse, a kind of fuzzy control method for jigger discharging is put forward. This method has many advantages over the conventional PID controller in terms of response speed, stability and robustness. It is effective to restrain the jig bed from over thick or empty, and the stability of the bed is markedly improved. The good results are obtained in factory tests.

教育-恐惧暴露干预对全髋关节置换术后恐动症患者的影响

目的探讨教育-恐惧暴露干预对全髋关节置换术后恐动症患者的影响。方法将96例全髋关节置换术后恐动症患者按住院时间分为对照组和干预组各48例。对照组给予常规护理干预,干预组给予教育-恐惧暴露干预。于患者出院前评价干预效果。结果干预组疼痛数字评分、恐动症评分显著低于对照组(均P<0.05);髋关节功能评分、一般自我效能感评分及出院准备度评分显著高于对照组(均P<0.05)。结论教育-恐惧暴露干预可降低全髋关节置换术后患者恐动症程度,缓解术后疼痛,提高自我效能感及出院准备度,促进髋关节功能恢复。

Mg-Zn-Mn-Nd合金作为一次镁空气电池阳极的腐蚀和放电行为

利用金相显微镜、X射线衍射仪、带有能谱仪的扫描电镜、电化学测试及恒电流放电测试对挤压态及固溶时效态Mg-6Zn-Mn-x Nd(ZM61,x=0,0.2,0.6,0.8,1.0,质量分数,%)合金微观结构、耐腐蚀性能及放电性能进行表征。结果表明,Nd的微合金化能促进ZM61合金晶粒细化,挤压态及固溶时效态ZM61-0.6Nd合金在所有合金中具有最为优异的耐腐蚀性能及放电性能;然而,热处理却降低挤压态合金的综合性能。其中,挤压态ZM61-0.6Nd合金的腐蚀电流密度为1.611×10^(-5)A/cm^(2),在电流密度为1和10m A/cm^(2)放电24 h的放电电位分别为-1.517 V和-1.336 V(vs SCE),其阳极利用率约36%,在所有研究合金中具有最好的综合性能。分析认为,挤压态ZM61-0.6Nd合金良好的放电性能可归因于镁合金耐腐蚀性能的提升及放电产物的开裂效应。

Parameter Self - Learning of Generalized Predictive Control Using BP Neural Network

This paper describes the self—adjustment of some tuning-knobs of the generalized predictive controller(GPC).A three feedforward neural network was utilized to on line learn two key tuning-knobs of GPC,and BP algorithm was used for the training of the linking-weights of the neural network.Hence it gets rid of the difficulty of choosing these tuning-knobs manually and provides easier condition for the wide applications of GPC on industrial plants.Simulation results illustrated the effectiveness of the method.

Self - Crosslinking Behavior of Self - Emulsion Water - Based Polyure-thane Coating Agents

The relation between structures and properties of polyurethane are investigated by modern physical and chemical methods.The results obtained are as follows:the effects of the content of self-crosslinking agent on the properties of polyurethane,i.e.,dispersion stability,dynamical viscoelasticity and mechanical properties are discussed.It is found that the optimum molar ratio of epichlorohydrin and diethylenetriamine is 1:2.A mois-

Culture Self- Consciousness in Transmission of Chinese Philosophy from the Perspective of English Globalization -- Taking the Belt and Road Initiative for Example

The Belt and Road Initiative contains the aspiration of Chinese nation to pursue ideological freedom and desire of strengthening international exchanges and cooperation. This paper takes the Belt and Road Initiative for example,emphasizing the interpretation of the inheritance and development of Chinese culture so as to study the importance of Culture Self-Consciousness in Chinese Philosophy,in the context of English globalization. That is to say,this paper stresses the spirits and the stand of nation 's demonstration on pursuing peace,cooperation and sustainable development in the civilization continuity from traditional China to the contemporary China,with practical philosophic view.

稀土镧对Mg-7Al-2Zn镁合金阳极材料腐蚀和电化学性能的影响

制备了Mg-7Al-2Zn、Mg-7Al-2Zn-0.05La、Mg-7Al-2Zn-0.10La 3种镁合金阳极材料,研究了稀土镧元素对合金在质量分数为3.5%的NaCl溶液中的腐蚀和电化学性能的影响。采用析氢和自腐蚀测试、扫描电子显微镜、电化学工作站、蓝电测试系统,研究了镁阳极的腐蚀行为和电化学性能。结果表明:镧元素的添加显著抑制了Mg-7Al-2Zn合金的析氢反应,提高了合金的耐蚀性,腐蚀方式由不均匀腐蚀向均匀腐蚀转变。添加少量的La可以保持镁合金的活性。Mg-7Al-2Zn-0.05La合金作为阳极材料时,镁空气电池的放电电压和能量密度达到最大值,分别为0.96 V和1092.8 mWh·g^(-1)。

Characteristics of Nanosecond Pulsed Discharges in Atmospheric Helium Microplasmas

Microplasmas are very interesting due to their unique properties and achievable regimes maintained at atmospheric pressures. Due to the small scales, numerical modeling could contribute to the understanding of underlying phenomena as it provides access to local parameters--and complements experimental global characteristics. A self-consistent formalism, applied to nanosecond pulsed atmospheric non-equilibrium helium plasmas, reveals that several successive discharges can persist as a result of a combined volume and dielectric surface effects. The valuable insights provided by the spatiotemporal simulation results show the critical importance of coupled gas and plasma dynamics--namely gas heating and electric field reversals.

Research of magnetic self-balance used in a repetitive high voltage rectangular waveform pulse adder

Compared with a sinusoidal operation, pulsed operation has more homogeneity and more efficiency in dielectric barrier discharge. In this paper, an improved pulse adder is designed and assembled to create repetitive high voltage rectangular pulses when resistive loads or capacitive loads exist. Beyond the normal pulse adder based on solid-state switches, additional metal- oxide-semiconductor field effect transistors are used in each stage for a faster falling edge. Further, the voltage difference between stages is eliminated by balancing windings. In this paper, we represent our theoretical derivation, software simulations and hardware experiments on magnetic self-balance. The experiments show that the voltage difference between stages is eliminated by balancing windings, which matches the result of simulations with almost identical circuits and parameters.

Numerical Calculations of Some Plasma Parameters of the Capacitively Coupled <i>RF</i>Discharge

Numerical calculations by using a self-consistent model of the collisional sheath for the capacitively coupled RF discharge are our target. The results indicated that, at high pressure, the ohmic heating is usually the dominant heating mechanism in the discharge. The power dissipated in the sheath is calculated and compared with the measured data. Moreover, we indicated that, when the gas pressure is increased, the calculated dissipated power is decreased also while the measured input RF power is increased. Furthermore the sheath thickness of the capacitively coupled discharge is calculated and in the same order of the electron oscillation amplitude in the RF field, while the ionization mean free path is shorter than it.

锂离子电池自放电K值检测系统设计

锂离子电池自放电检测对评估单体锂离子电池或电池组的容量、循环特性和使用寿命具有重要作用。快速检测开路状态下锂离子电池存储电量自发消耗是目前该领域的研究热点。采用开路电压法,通过测量单位时间内锂离子电池的电压降,即自放电K值,表征其自放电程度,设计了锂离子电池自放电K值检测系统。该系统由上、下位机组成,两者之间采用Type-C方式连接,可对锂离子电池进行自放电率检测。以三元锂离子电池为测试对象,对其进行14 d的静置实验,检测静置过程中的自放电K值。测试结果表明该系统不仅缩短了锂离子电池自放电检测时间,而且可准确检测锂离子电池的自放电率。在锂离子电池20%、40%、60%、80%、100%5种荷电状态,20、50、-20、-40℃4种温度条件下对锂离子电池进行自放电K值检测。依据K值测试结果,可分析荷电状态和自放电环境温度对锂离子电池自放电率的影响。

一种放电打火保护电路的设计

直流高压电源在制造及使用的过程中经常由于放电打火产生突变输出而损坏电源内部器件,进而造成频繁的维修更换。为解决这一问题,设计了一种用于直流高压电源的放电打火保护电路,可通过互感原理检测电源电路中出现的放电打火故障,并由保护电路产生放电打火信号,使可控硅与继电器工作,通过减法器电路实现高压电源输出的突变抑制,从而使得高压电源输出维持在安全电压值,并且可通过继电器调节抑制持续时间,时间结束后电压自动恢复到初始设定值。结果表明,放电打火检测装置电路结构合理、灵敏可靠,在实现放电打火保护功能的同时满足自恢复要求,为电源电路系统的安全运行提供了有力保障。

微尺度下场致发射对电晕放电的影响机理

场致离子化微电晕器件基于一维纳米材料的电场增强效应,可产生大气压非平衡微等离子体,适用于气体检测以及生物医疗等领域,具有响应快、低功耗等特点。但微尺度下的电晕放电属于局部自持的低能放电,其场致发射的作用及影响机制尚不清晰。因此文章基于流体-化学混合模型框架,融合F-N发射模型,建立了常温常压N2-O2混合气体的二维微电晕放电模型。通过与无场致发射放电模型对比,探索不同间距下场致发射对放电动态过程的影响,发现针-板间距减至15μm时,两种模型放电过程差异很小,表明放电以二次电子发射机制为主导,当间距减至10μm时,两种模型的放电强度相差近1倍,场致发射的作用及影响不可忽略;通过进一步对电子密度分布、空间电场分布、电流密度等参量进行动态分析,发现场致发射、空间碰撞电离反应和离子轰击二次电子发射之间存在链锁影响规律。

电子纸产品用锂-二氧化锰电池性能研究

为了研究锂-二氧化锰电池作为电子纸产品电源解决方案的适用性,基于锂-二氧化锰电池的原理、性能开展分析,梳理了放电性能、自放电率性能、存储性能及安全性能的试验。试验结果表明,锂-二氧化锰电池具有工作温度范围广、能量密度高、放电平台高、自放电率低、存储时间长、储存期间无需任何维护及安全性能高特点,验证了该特点满足电子纸的应用。

类风湿性关节炎患者出院准备度情况及影响因素分析

目的调查类风湿性关节炎患者出院准备度情况,并对其影响因素进行分析。方法采用目的抽样法,研究对象选择2021年4月-2022年2月在本院收治住院的130例类风湿性关节炎患者,采用一般资料调查表、出院准备度量表、出院指导质量量表、关节炎自我效能感量表-8进行横断面调查,多元线性回归分析影响因素。结果96.92%的类风湿性关节炎患者表示已做好出院回家的准备,出院准备度总分为(93.58±5.80)分。出院准备度与自我效能感、出院指导质量呈正相关(r=0.436,P<0.001;r=0.553,P<0.001)。单因素分析显示,差异有统计学意义的变量为年龄、文化程度、合并疾病情况、病程年限和关节功能(P<0.05)。多元线性回归分析显示,影响类风湿关节炎患者出院准备度的主要因素为文化程度、病程年限、关节功能、关节炎自我效能感和出院指导质量(R^(2)=0.530,调整R^(2)=0.511,F=27.920,P<0.001)。结论类风湿性关节炎患者出院准备度处于中高水平,主要受文化程度、病程年限、关节功能、自我效能感、出院指导质量的影响。临床医务工作者应与患者正向沟通,帮助树立长期对抗疾病的信心,同时不断改进出院指导质量,以提高患者出院准备度。