共查询到19条相似文献,搜索用时 118 毫秒
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用化学共沉淀法合成了A l掺杂N i(OH)2,用XRD表征了合成样品的结构特征:研究了合成样品的循环伏安性能,以及用A l掺杂N i(OH)2为正极活性物质的Zn/N i试验电池的充放电性能。研究结果表明:所合成的A l掺杂N i(OH)2为具有α-型晶体结构的材料,A l掺杂N i(OH)2具有优良的电化学可逆性、良好的充放电性能和较好的电化学循环性能;A l掺杂N i(OH)2作为正极活性物质的Zn/N i试验电池等250次充放电循环容量保持率130.1%,最高放电比容量为420.5mAh/g。 相似文献
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β-NiOOH的制备及充放电性能 总被引:14,自引:0,他引:14
电池正负极材料有充放电态之分 ,如 Mn O2 、Zn处于充电态 ,Ni(OH) 2 、MH、Li Co O2 、L i Ni O2等处于放电态 ,将起始荷电态不同的电极组装成电池 ,必然存在充放电态不匹配的问题 ,给电池化成带来困难 [1,2 ] .如 Zn/Ni电池正极改用充电态Ni OOH为原材料 ,则负极就可用充电态 Zn为原材料 ,很显然 Zn作为负极材料优于 Zn O,这就引发了将 Ni(OH) 2 氧化为 Ni OOH的研究 .本文采用改进的化学氧化法由β- Ni(OH ) 2 制备β-Ni OOH粉体 [3,4 ] ,对纯样及其与 Mn O2 混合的掺杂样的充放循环性能和反应机理进行了研究 .所用试剂… 相似文献
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目前镍基碱性二次电池正极活性物质广泛采用的β-Ni(OH)2存在比容量偏低、不能或不适合与单质锌直11接搭配制作一次或二次锌镍电池等缺点[1],因此,合成充电态高比容量的NiOOH具有重要意义.Al、Zn等掺杂改性的α-Ni(OH)2在强碱性电解质中稳定,充放电可逆性好,质量比容量可达400mAh/g以上[2~4],如果直接合成其氧化态物质γ-NiOOH,有望获得较好的电性能,从而为镍基碱性电池提供一种新型的正极活性材料. 相似文献
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系统研究了铂、镍、不锈钢(SS)、铜、铝五种金属集流体和碳纤维、石墨箔、碳布三种碳纸集流体对“一代” (Mg(AlCl2BuEt)2/THF)、“二代” ((PhMgCl)2-AlCl3/THF)可充镁电池电解液阳极氧化分解电位和镁沉积-溶出性能的影响。金属镍、不锈钢、铜、铝作为可充镁电池正极的集流体时, 充电至一定电压时自身均会发生腐蚀。其中, 镍和不锈钢可用作充电电压在2.1V(vs Mg/Mg2+)以下正极材料的集流体; 铜可用作充电电压在1.8V(vs Mg/Mg2+)以下正极材料的集流体。碳集流体比金属集流体具有更高的稳定性, 其中, 碳布作为集流体, 适用于充电电压在2.25V(vs. Mg)(对“一代”电解液)和2.95V(vs Mg/Mg2+)(对“二代”电解液)以下的正极材料。 相似文献
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为了改善Ni(OH)2的电化学性质,提高锌镍电池的充放电性能,用化学共沉淀法合成了混合铝镍氢氧化物Ni/Al(OH)x.用XRD和FTIR表征了Ni/Al(OH)x样品的晶体结构及IR光谱特征;测试了用Ni/Al(OH)x为正极活性物质的Zn/Ni实验电池的充放电性能.研究结果表明:所合成的Ni/Al(OH)x具有α-Ni(OH)2的晶体结构;Ni/Al(OH)x活性物质在充放电过程中主要为γ/α循环,以Ni/Al(OH)x作为正极活性物质的Zn/Ni试验电池具有优良的循环性能,其最高放电比容量为379mA·h/g. 相似文献
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外掺Y2O3对镍氢电池正极高温性能的影响 总被引:8,自引:2,他引:8
研究了外掺Y2O3对镍氢电池镍正极高温性能的影响. 通常镍正极在高温下放电比容量会骤然降低, 为了提高其高温性能, 进行了球型Ni(OH)2外掺不同比例Y2O3的实验, 对压制的镍电极在不同温度下的充放电情况进行了细致的研究. 研究发现外掺Y2O3的球型Ni(OH)2电极比普通球型Ni(OH)2电极的放电比容量在高温下要高出很多, 在0.2 C充放电情况下外掺1%是最佳比例, 它比普通球型Ni(OH)2电极的放电比容量要高出35%以上, 在1 C充放电情况下外掺0.2%是最佳比例, 它比普通球型Ni(OH)2电极的放电比容量要高出15%以上. 同时对外掺Y2O3提高镍正极放电比容量的原因也进行了初步探讨. 相似文献
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Zifang Zhao Yue Liu Fang Wan Shuai Wang Nannan Zhang Lili Liu Anyuan Cao Zhiqiang Niu 《中国化学快报》2021,32(2):594-597
The recent boom in large-scale energy storage system promotes the development of lithium-oxygen batteries because of their high theo retical energy density.However,their applications are still limited by the sluggish kinetic,insoluble discharge product deposition and the undesired parasitic reaction.Herein,the free-standing nitrogen doped reduced graphene oxide/Co(OH)_2(NRGO/Co(OH)_2) composite films were prepared by a facile hydrothermal method,The NRGO/Co(OH)_2 composite films display interconnected three-dimensional conductive network,which can not only promote the diffusion of O_2 and the transport of electrolyte ions,but also provide abundant storage space for discharge products.Moreover,the introduction of nitrogen-containing functional groups results in improved conductivity and electron adsorption ability,which can facilitate electron transport and enhance the surface catalytic activity.Combining with excellent catalytic performance,the lithium-oxygen batteries with NRGO/Co(OH)_2 composite film cathodes deliver low charge overpotential and excellent cycling performance. 相似文献
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新型非对称电化学电容器的电极匹配研究 总被引:5,自引:1,他引:4
活性炭负极容量的有效利用率是导致双电层电化学电容器和C/Ni(OH)2非对称电化学电容器容量性质差异的主要因素,并可将其作为非对称电化学电容器容量设计和测算的依据;本文引入Ni(OH)2正极有效活性物质概念,以正极有效活性物质的量匹配负极的设计容量,从而优化正、负极的容量匹配,改善非对称电化学电容器的容量和大电流性能. 相似文献
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利用软嵌式粉末电极技术研究了Y(OH)3包覆对球形Ni(OH)2电化学性能的影响. 循环伏安结果表明, 在球形Ni(OH)2的氧化过程中存在Ni(Ⅲ)和Ni(Ⅳ)的两步氧化反应, 产生的Ni(Ⅳ)不稳定, 能分解产生NiOOH和氧气, 所以可将Ni(Ⅲ)→Ni(Ⅳ)看作副反应. Y(OH)3包覆层对Ni(OH)2氧化过程后期的副反应, 特别是Ni(Ⅲ)→Ni(Ⅳ)具有较好的抑制作用. 由包覆后的Ni(OH)2制成的模拟电池表现出很好的高温性能, 在1C充放电条件下, 当Y的摩尔分数为1.61%时, 在60 ℃时所对应的容量保持率可达到25 ℃的92.7%; 当Y的摩尔分数仅为0.55 %时, 在60 ℃时所对应的质量比容量也可达到241.3 mA·h/g. 相似文献
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《Journal of Energy Chemistry》2017,26(3):481-487
LiNi_(0.915)Co_(0.075)Al_(0.01)O_2(NCA) with Zr(OH)_4 coating is demonstrated as high performance cathode material for lithium ion batteries(LIBs). The coated materials are synthesized via a simple dry coating method of NCA with Zr(OH)_4 powders, and then characterized with scanning electron microscopy(SEM), transmission electron microscopy(TEM) and X-ray photoelectron spectroscopy(XPS). Experimental results show that amorphous Zr(OH)_4 powders have been successfully coated on the surface of spherical NCA particles, exhibiting improved electrochemical performance. 0.50 wt% Zr(OH)_4 coated NCA delivers a capacity of 197.6 mAh/g at the first cycle and 154.3 mAh/g after 100 cycles with a capacity retention of 78.1% at 1 C rate. In comparison, the pure NCA shows a capacity of 194.6 mAh/g at the first cycle and 142.5 mAh/g after 100 cycles with a capacity retention of 73.2% at 1 C rate. Electrochemical impedance spectroscopy(EIS) results show that the coated material exhibits a lower resistance, indicating that the coating layer can efficiently suppress transition metals dissolution and decrease the side reactions at the surface between the electrode and electrolyte. Therefore, surface coating with amorphous Zr(OH)_4 is a simple and useful method to enhance the electrochemical performance of NCA-based materials for the cathode of LIBs. 相似文献
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We report on the synthesis, characterization, and electrochemical application of Ca(OH)2-, Co(OH)2-, and Y(OH)3-coated Ni(OH)2 tubes with mesoscale dimensions. These composite tubes were prepared via a two-step chemical precipitation within an anodic alumina membrane under ambient conditions. The morphology and structure of the as-synthesized samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and high-resolution transmission electron microscopy (HRTEM) equipped with energy dispersive spectroscopy (EDS). The results showed that the size of the tubes was of mesoscale dimension and the proportion of the tube morphology was about 95%. The as-prepared composite tubes were further investigated as the positive-electrode materials of rechargeable alkaline batteries. Electrochemical measurements revealed that the Ni(OH)2 tubes coated with Ca(OH)2, Co(OH)2, and Y(OH)3 exhibited superior electrode properties including high discharge capacity, excellent high-temperature and high-rate discharge ability, and good cycling reversibility. The mechanism analysis suggests that both the coated layers and the unique hollow-tube structures play an indispensable role in optimizing the electrochemical performance of nickel hydroxide electrodes. 相似文献