| CO32-/Co2+/Ni2+浓度对混合相纳米Ni(OH)2物化性能的影响 | |
| Effect of the CO32-/Co2+/Ni2+ Concentration on the Physicochemical Properties of Mixed Phase Nano-Ni(OH)2 | |
| 摘要: 以NiCl2、Co(NO3)2、Na2CO3为主要原料，采用超声波辅助沉淀法制备了混合相纳米Ni(OH)2，研究了Co掺杂比例、缓冲剂Na2CO3用量及反应物Ni2+浓度对Ni(OH)2的晶相结构、形貌、粒径及电化学性能的影响。结果表明，混合相结构的α-Ni(OH)2成分随Co掺杂比例增大而增加。较高的CO32-和Ni2+浓度有利于α-Ni(OH)2的生成。TEM测试表明，样品晶粒呈针状形态，其长径比随着Na2CO3用量增加而减小，平均粒度在60~90 nm之间。将纳米样品以8wt%与工业用微米级β球镍混合制成复合电极，其电极的放电比容量随Na2CO3用量的增加先增大后减小。当Ni2+浓度为0.4 mol·L-1、Na2CO3用量为0.5 g时，其电极(Co含量1.02wt%)的充电效率最高，放电比容量最大，0.5C倍率下高达306.9 mAh·g-1，比纯球镍电极提高30%。探讨了复合电极能较大幅度提高放电比容量的机理，提出纳米α-Ni(OH)2同时充当活化中心起催化作用的观点。 | |
| 关键词: 缓冲剂Na2CO3 反应物浓度 混合相纳米Ni(OH)2 超声波辅助沉淀法 电化学性能 | |
| 基金项目: | |
| Abstract: The mixed phase nanometer Ni(OH)2 was prepared by ultrasonic-assisted precipitation method using NiCl2、Co(NO3)2 and Na2CO3 as main materials. The crystal structure, morphology, particle size distribution and electrochemical performance affected by doping ratio, buffer and Ni2+ concentration were characterized. The results indicate that different Co-containing Ni(OH)2 were co-existence with α and β phase and the proportion of α-Ni(OH)2 significantly increase with the increase of doping ratio. The higher CO32- and Ni2+ concentration is beneficial to form α-Ni(OH)2. The transmission electron microscope (TEM) results show that all samples have the needle-like morphology, the length-diameter ratio decreased with the increase of Na2CO3 and the average particle size was between 60~90 nm. Composite electrodes were prepared by mixing 8wt% nickel hydroxides with commercial micro-size spherical nickel. The discharge capacities of electrodes increased initially and then decreased with the increase of Na2CO3. When Ni2+ is 0.4 mol·L-1 and Na2CO3 is 0.5 g, the electrode (the Co is 1.02wt%) has the largest discharge capacity, which reaches 306.9 mAh·g-1 at 0.5C rate, and is 30% higher than that of spherical nickel electrode. The mechanism was investigated to explain the larger discharge capacity, proposing that nanometer α-Ni(OH)2 act as activation center played a catalytic role. | |
| Keywords: buffer Na2CO3 concentration of reactants mixed phase nanometer Ni(OH)2 ultrasonic-assisted precipitation method electrochemical performance | |
| 摘要点击次数: 2099 | |
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| 庄义环,朱燕娟,赵汝冬,林晓然,刘泳林,张树杰,许庆胜.CO32-/Co2+/Ni2+浓度对混合相纳米Ni(OH)2物化性能的影响[J].无机化学学报,2013,29(2):338-344. | |
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