Ag改性氟化石墨材料及电化学性能

采用化学还原法对氟化石墨材料(CFx)进行金属(Ag)掺杂改性。采用XRD、SEM、能量散射谱、电化学阻抗谱及恒流放电测试,分析CFx/Ag复合材料的电化学性能。与纯CFx相比,制备的CFx/Ag复合材料的放电比容量较高。以0. 1 C放电至1. 50 V,最高达790 m Ah/g,且没有电压滞后现象,中值电压高达2. 62 V;0. 5 C、1. 0 C放电时,低波电压分别提高0. 82V、0. 83 V。     

Li/CF_x电池的制备及性能研究

以氟化石墨为正极活性物质、锂片为负极,制备成104860型软包装锂/氟化碳(Li/CF_x)电池。用差示扫描量热(DSC)、SEM测试对氟化石墨的热稳定性、形貌进行分析;研究正极组分配比、电解液类型及用量对Li/CFx电池性能的影响;考察Li/CF_x电池的倍率特性。氟化石墨具有良好的热稳定性,在500℃以上才开始分解,呈规整的层状结构,表面光滑、大小较均匀,有利于电子的传输。正极组分氟化石墨、导电剂和粘结剂质量比为87.0∶5.5∶7.5,电解液1 mol/L Li PF6/EC+DMC+EMC添加量为5 g/Ah的Li/CFx电池性能较好。以0.05 C、0.10 C、0.20 C和0.50 C的倍率放电至1.5 V,容量分别为2.56 Ah、2.48 Ah、2.46 Ah和2.36 Ah。     

FeF2@C球形核壳复合结构的制备及其电化学性能

氟化亚铁(FeF2)因较高的理论比容量和充放电电势而成为高能量密度锂电正极材料的优选,但其导电性差、电化学过程中体积变化等因素阻碍了其实际应用.本文以二茂铁和氟化铵作为前驱体,采用高温热反应法合成了碳层包覆氟化亚铁(FeF2@C)球形核壳纳米复合结构,并结合XRD、SEM-EDS、TG对样品的物相、形貌和结构进行表征,...     

镁锂混合电池TiO2空心球正极材料的制备与性能

探究了利用硬模板法,通过SiO2纳米球模板及钛酸四丁酯的水解包覆最终刻蚀获得具有规则形貌的锐钛矿型TiO2空心纳米球,并以所得TiO2空心纳米球作为正极材料、纯镁为负极,分别以0.4 mol/L PhMgCl-AlCl3/THF(APC)+1.0 mol/L LiCl为混合双盐电解液组装镁锂混合离子电池以及以0.4 mol/L APC电解液组装镁离子电池进行电化学测试对比.实验结果表明,所制得的锐钛矿型TiO2空心纳米球在镁锂混合离子电池中作正极时,60 mA/g电流密度下首次放电比容量72.9 mAh/g,50次循环后能保持102.5 mAh/g,然而,当其作为镁离子电池正极材料时,表现出较差的电化学性能.实验结果表明:TiO2空心纳米球的空心结构设计和氯化锂作为电解液添加剂有助于改善正极材料的电化学性能.     

锂/氟化碳电池的安全性能

氟化石墨为正极,锂为负极,研制了10 Ah软包装锂/氟化碳(Li/CFx)电池。通过过放、短路、针刺和挤压等安全实验,对Li/CFx电池的安全性能进行了测试。电池以0.20 C倍率过放电至-3.0 V,没有出现漏液、爆炸和起火现象,表面的最大温升不超过33℃;电池经过短路实验,没有出现漏液、爆炸和起火现象,表面的最大温升不超过39℃;电池经过针刺和挤压后,没有出现爆炸、起火现象,表面的最大温升不超过10℃。     

改性氟化碳材料结构与电性能的研究

通过对氟化碳原材料进行表面还原处理,制备改性氟化碳材料。通过热重、傅里叶红外-拉曼光谱和电化学测试等研究了表面处理对氟化碳材料结构和电化学性能的影响。结果表明:表面处理降低了氟化碳的氟化度,提高了碳环的规整度和倍率性能。以0.2 C倍率放电,电池的电压平台提高了约100 m V。     

纳米Si/C复合微球材料制备及电化学性能表征

通过高温热解法合成不同纳米硅含量的Si/C复合微球材料并对其形貌及电化学性能进行了探究。采用X射线衍射(XRD)、扫描电镜(SEM)、透射电镜(TEM)、恒电流充放电和循环伏安测试等技术对样品进行表征分析。电化学测试结果表明:当样品中的硅含量为8%(质量分数)时,制备的纳米Si/C复合微球负极材料在100 m A/g的电流密度下,首次可逆充电比容量为532.0 mAh/g,循环100次后,比容量可稳定在321.8 mAh/g。该结果归因于无定形碳良好的导电性及较高的比表面积。     

硫化物作为储能材料及电催化的研究进展

综述过渡金属硫化物复合材料在制备方法、结构特点、电化学储能和转换等方面的研究进展,包括各种纳米结构,如纳米花、纳米球、纳米片和纳米立方体等.金属硫化物用于锂离子电池、钠离子电池、钾离子电池和电催化时,具有较好的电化学性能,如循环稳定性和倍率性能好,良好的对析氢反应、析氧反应和二氧化碳还原的电催化活性.展望过渡金属硫化物复合材料作为电池负极材料和催化剂的应用和发展前景.     

微纳米MnO2中性电解液中电容性能研究

通过液相共沉淀、低温水热法等方法制备了核壳、海胆、纳米片团聚微球、纳米棒团聚微球不同形貌的微纳米二氧化锰材料,采用X射线衍射、扫描电子显微镜、比表面积测试、循环伏安法对其晶体结构、表面形貌及电化学性能进行研究。结果表明:结晶度、比表面积对所合成的二氧化锰材料电容性能有一定影响,但并不是造成比电容差异最主要原因,而材料的形貌微结构对电容性能有着更重要的影响。纳米棒团聚微球在~8 nm处具有集中的孔径分布,比表面积达102.3 m2/g,高载量厚电极(10 mg/cm2,100μm)条件下,1 mol/L Na2SO4溶液中纳米棒团聚微球2 mV/s扫速时的放电比电容为143 F/g;200 mV/s时,放电比电容为52 F/g,表现了很好的电容特性,这种微纳米介孔材料是一种极具潜力的电化学电容器电极活性材料。     

锂离子电池用石墨烯基纳米复合物的进展

综述了锂离子电池石墨烯(GNS)基纳米复合物电极材料的研究进展,包括活性物质种类、GNS基纳米复合物电极材料的制备方法、微结构特征和主要电化学特性.对GNS基纳米复合物电极材料的研究方向进行了展望.     

MoS2/C纳米复合材料的合成及其电化学性能研究

理论比能量高达2 600 Wh/kg的锂硫电池已经成为锂电池研究热点,然而硫导电性不好、穿梭效应和锂化体积效应较大等问题阻碍了锂硫电池的产业化。将无定型多孔碳材料的高导电性和极性MoS₂的固硫作用相结合改善锂硫电池的电化学性能。所得的S@MoS₂/C在0.05 C和2 C电流密度下的放电比容量分别为1 507和406.3 mAh/g,比S@MoS₂在相同电流密度下的放电比容量（1 400和345.7 mAh/g）更高。在循环性能测试中,S@MoS₂/C容量保持率为46.9%,要高于S@MoS₂（39.1%）。因此,MoS₂/C复合材料作为硫载体可以显著改善锂硫电池性能。     

镍钴锰酸锂的制备及高电压充放电性能

用共沉淀-机械球磨-高温煅烧法制备纳米三氧化二铝(Al_2O_3)包覆镍钴锰酸锂材料,研究材料在高电压充放电条件下的电化学性能。XRD、SEM、容量微分(d Q)/电压微分(d U)和电化学性能测试结果表明:在镍钴锰酸锂颗粒表面得到了均匀的纳米级Al_2O_3包覆层,并提高正极材料的电化学性能。以0.5 C在3.0~4.6 V循环,Al_2O_3包覆量为0.5%材料第50次循环的放电比容量由未包覆材料的155.3 m Ah/g上升到172.7 m Ah/g。包覆处理可提升正极的热稳定性和高电压高温持续充电的时间,从而提高电池的高温安全性能。     

无人机用高电压钴酸锂的制备及性能

用机械球磨-高温煅烧法制备钴酸锂(LiCoO_2),然后进行磷酸铝(AlPO_4)包覆。XRD、SEM和电化学性能测试结果表明:制备的LiCoO_2为二次颗粒结构,表面有均匀的AlPO_4包覆层。在3.00~4.50 V以1.0 C充电、2.0 C放电,包覆AlPO_4材料第50次循环的放电比容量由未包覆材料的137.0 mAh/g上升到166.6 mAh/g。包覆处理可提升正极的热稳定性和高电压高温持续充电的时间,从而提高电池的高温安全性能。     

贮氢合金粉体包覆铜工艺

为改善稀土—镍基贮氢合金粉的抗氧化和耐粉化性,本文介绍了一种简单的化学镀铜法,该法工艺简单,成本低廉,可达到抗氧化和抗粉化的目的,并且能增强传热和导电性能,降低内阻、内压,使得由此包覆粉制出的电池的放电容量更高,放电电压更平稳。     

Industrial experiments on pulse corona simultaneous removal of NOx and SO2 from flue gas

The corona-induced simultaneous removal of NO_x and SO ₂ from flue gas is based on the application of narrow voltage pulses to an electrode structure similar to that of an electrostatic precipitator. The free electrons of the corona discharge, having energy up to 20 eV, originate active radicals which lead to the transformation of NO_x and SO₂ into their acids which can be neutralized to salt particulate by adding to the gas a basic compound such as ammonia and calcium hydroxide. The process has been investigated with a test rig installed in the slipstream of the flue gas duct of a coal-fired thermal power plant. The experiments were performed with three reactor modules of different geometries. Further experiments are necessary to assess the effect of different electrode geometries of the reactor, the efficiency of the process attainable with an improved coupling of narrow pulse power set to the reactor, and the practical ways for integrating the DeNO_x and DeSO₂ corona process with the solid particle collection system     

聚苯胺/活性炭复合材料的制备及电化学性质

采用溶液聚合原位复合法制备出不同配比的聚苯胺/活性炭复合材料,在分别用扫描电镜(SEM)、红外光谱法(IR)、热重分析法(TG)和电阻率测试研究复合材料的形态、表面官能团、热性能和电导性能的基础上,使用恒流充放电和循环伏安(CV)技术研究了聚苯胺/活性炭复合材料作为双电层电容器电极时的电化学性质。实验结果表明:复合材料呈现较高的热稳定性,当炭含量达到20%时复合材料的导电性最好;50%活性炭含量的电极比电容高达400F/g;电极反应可逆性良好。     

AC particle-triggered corona discharge in low pressure SF/sub 6/ gas

This paper deals with AC particle-triggered corona discharge as a follow-up to our previous research with DC voltage to clarify the particle-triggered corona discharge process in SF₆ gas. Corona current pulses, charges associated with a corona current pulse, and corona light pulses were observed with an aluminum ellipsoidal particle suspended in a parallel plane electrode system under a SF₆ gas pressure range of 30 kPalesPles50 kPa by changing the particle position. Corona mode, phase (Phi)-charge (q) characteristics as well as corona discharge processes were discussed and the following results were obtained. AC corona mode depended on the instantaneous applied voltage, voltage gradient as well as the particle position and then, the Phi-q characteristics were also affected by those parameters. Charges flow into the floating particle due to coronas on the both tips of particle and excite field fluctuations around the opposite side of particle in addition to the applied AC field. The field fluctuation in SF₆ gas by the corona charges was about 4% of the applied field and much lower than that in air gap which was about 70%. That is, the corona development was suppressed effectively by high electron affinity of SF₆ gas even in the case of floating particle. The less effective interference between coronas on the both side of particle in SF₆ gas results in an obscure local minimum in the breakdown voltage characteristics as the particle is in the vicinity of electrode as contrasted with a drastic fall in the breakdown voltage by the particle in air     

The influence of ions on the thermally stimulated discharge currentspectra of water-treed additive-free low-density polyethylene

The effects of water treeing on steady state dc currents and thermally stimulated discharge current spectra (TSDC) of additive-free low density polyethylene (LDPE) were studied using heavily water-treed material in solutions of LiCl, LiCl plus HCl, MnCl₂ and FeCl ₃. Significant changes in the dc conductivity of treed samples are attributed to the effects of ions. For such samples, graphs of the logarithm of current versus inverse temperature show three distinct linear regions. The transition temperatures demarcating these regions appear to correlate with those reported for thermal relaxations. TSDC spectra of water-treed samples show a dependence on both the ionic solutions used and on the poling conditions. For LiCl treed samples, twin peaks in the TSDC spectra were produced only under specific poling conditions. These peaks may be correlated with thermal relaxations observed using differential scanning calorimetry (DSC). The melting point temperature and the melting peak area derived from DSC spectra were reduced by treeing     

Gas cleaning with semi-wet type plasma reactor

An experimental study on the removal of NH₃, NO, NO_x in concentration of 10-40 ppm in air has been carried out using plasma chemical reactions in a streamer corona discharge. The results of the performance of dry type and semi-wet type reactors are compared. The effects of different type of applied voltages such as rectangular pulse, 60-Hz sinusoidal, and 18-kHz alternating voltages are investigated. During NO removal, O₃ and NO₂ are produced. NO₂ can, partially, be removed with higher power input into the discharge. Another undesirable pollutant, namely N₂ O, is also produced, especially, in case of dry reactors having long residence time (~2.4 s). N₂O production decreases, essentially, to zero at 0.6-s residence time while using a semi-wet reactor. In general, higher removal efficiency has been obtained with pulse voltage in a semi-wet reactor. NH₃ in air appears to produce ozone and ammonium nitrate in a discharge. The performance of semi-wet reactors an the removal of submicron dust particles has also been investigated and very high removal efficiency (~93% at 0.6-s residence time) has been obtained