共查询到19条相似文献,搜索用时 171 毫秒
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烧结式电极孔率和强度与烧结工艺关系的研究 总被引:1,自引:0,他引:1
研究了烧结电极孔率和强度与烧结工艺的关系,寻找到既能满足强度要求,又能使烧结电极孔率有较大提高的工艺参数,即烧结速度在100~120m/h之间,炉温在950℃左右,电极孔率达到81%~83%之间.电极活性物质填充量明显增加,再配合其它有效措施,电极容量达到540mAh/cm~3以上,满足了高比能量电池的要求. 相似文献
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将4BS晶种作为添加剂引入到正极原料中,且当添加量为1%时,4BS晶种能引发极板中生成细致、均匀的4BS颗粒,在很大程度上能够提高极板性能的一致性。配合75℃高温固化工艺,生极板中4BS含量可提高到75%,游离铅氧化效率更高。4BS晶种的引入还可将铅膏的孔率提高到46.6%,有利于氧气进入到铅膏内部,使得固化更易于进行,极板活性物质间的结合力增强。通过优化化成工艺,4BS晶种能提高熟极板中α-PbO_2含量,使活性物质结晶细致。实验表明,4BS晶体的引入能够缩短生产时间,提高了极板的化成效率和一致性,最终延长电池的使用寿命。 相似文献
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本文叙述了具有特殊隔板和对极板施加机械压力的装置的新颖的铅蓄电池结构。对正极板的特殊排列可减少活物质脱落。这些电池是采用30分钟快速充电进行循环的,并报告了循环寿命为300~3000周期。根据孔率测定的结果来看,正极活物质在几百次循环之后,似乎停止了变化。 相似文献
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极板活性物质对铅蓄电池寿命的影响 总被引:1,自引:0,他引:1
铅蓄电池极板上的活性物质,决定着蓄电池的基本容(旦力),这是无可非议的。近年来的生产实践,却重点指出铅蓄电池的使用寿命在相当程度上依赖于极板的活性物质。正极板栅上的活性物质脱落,负极板栅上活性物质的膨胀,都是目前铅蓄电池过早损坏的主要原因之一。 相似文献
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铅酸蓄电池添加剂的研究 总被引:1,自引:0,他引:1
研究了常温下铅酸蓄电池在正极活性物质中加入高纯石墨对电极性能的影响 ,通过不同倍率放电容量和放电曲线的测试 ,证明在正极活性物质中加入高纯石墨 ,提高了正极的孔隙率与润湿性能 ,增加了电极微孔中的酸含量 ;同时降低了电极内阻 ,改善了电极的导电性 ,因此提高了初始放电容量和活性物质利用率。实验表明正极中加入不同产地的石墨对电极性能的影响也不同 ,其中以加入平度产的高纯石墨正极充放电性能最好 ,活性物质利用率最高。所使用的虽然是高纯石墨 ,但仍然含有少量杂质 ,所以电极的自放电量有所增加 相似文献
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Pb(Zr,Ti)O3 ceramics with homogenous, anisotropic porosity were manufactured and the influence of the anisotropic porosity on the dielectric
and piezoelectric properties was studied. Image analysis allowed the quantification of the preferential orientation and the
calculation of the distribution of the aspect ratio of the pores. The different dependence of the permittivities e33T\varepsilon _{33}^T and e11T\varepsilon _{11}^T on the porosity content demonstrates that the population of pores is constituted of a high volume of pores with low aspect
ratio and a low volume of pores with high aspect ratio. In view of the quantitative results obtained on the microstructure,
an explanation of the frequency dependence of the dielectric and piezoelectric behaviour is suggested. Furthermore, the higher
d31 piezoelectric coefficient in the material with anisotropic pores than in material with isotropic pores is related to higher
effective fields which are a consequence of the enhanced longitudinal mobility of the material under transverse stress. 相似文献
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In many applications where both high temperature and high electrical stress exist, little is known about the interaction of the electrical and thermal properties of the materials involved. This paper is a study of this interaction for a material which we call a concrete, and is a fine alumina powder mixed with a cement, i.e. calcium aluminate (CaOAl2O3) slurry, which cures in the same manner as a concrete. The porosity of the product depends upon the relative volume of the hydrated cement to the volume of the spaces between the alumina particles, and the shapes of the pores may be changed by choosing the mix of various particle sizes of alumina particles. In this study, specimens of this material were cast between uniform field electrodes in one case, and between nonuniform field electrodes in the other, cured and dried to remove residual moisture, and tested for electric strength. It is well known that the electric strength of porous materials is low and nearly the same as the electric strength of the gap between the same electrodes in air in the absence of the solid porous material. This paper shows that for this material and only at porosities <20%, as measured by a mercury porosimeter, does the electric strength become larger than that of air and become a significant function of the porosity and of the distribution of pore volume among pores of differing equivalent pore diameter. The uniformity of the field had no noticeable effect 相似文献
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异步电动机矢量控制系统需要电动机电阻和电感参数.介绍了在调试时,面对1台电机如何估算和测量这些参数,方法有:用电动机铭牌或样本数据估算参数,通过空载和短路实验测取参数,利用变频器测取参数及在运行中修正参数.这些方法也是设计调速系统中自调试功能的基础. 相似文献
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质子交换膜燃料电池(PEMFC)阴极扩散层孔隙率分布对电池性能影响很大。建立了一个单电池的三维模型,分别考虑了阴极扩散层孔隙率单一分布、线性梯度分布、随机分布等情况,并用有限控制体法对模型进行了求解。研究结果表明,在大电流密度下,阴极扩散层孔隙率的不同分布形态会不同程度地影响阴极氧气质量传输和液态水的排出,从而影响电池性能。 相似文献
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