Nogueira C A, Margarido F
Instituto Nacional de Engenharia, Tecnologia e Inovação (INETI), Department of Materials, Estrada do Paço do Lumiar, 1649-038 Lisboa, Portugal.
Waste Manag. 2007;27(11):1570-9. doi: 10.1016/j.wasman.2006.10.007. Epub 2006 Dec 12.
The present work aimed at the chemical and physical characterization of spent sealed MONO-type Ni-Cd batteries, contributing to a better definition of the recycling process of these spent products. The electrode material containing essentially nickel, cadmium and some cobalt corresponds to approximately 49% of the weight of the batteries. The remaining components are the steel parts from the external case and the supporting grids (40%) containing Fe and Ni, the electrolyte (9%) and the plastic components (2%). Elemental quantitative analysis showed that the electrodes are highly concentrated in metals. The phase identification achieved by X-ray powder diffraction combined with chemical analysis and leaching tests allowed the authors to proceed with the composition of the electrode materials as following: cathode: 28.7% metallic Ni, 53.3% Ni(OH)2, 6.8% Cd(OH)2 and 2.8% Co(OH)2; anode: 39.4% metallic Ni and 57.0% Cd(OH)2. The morphology of the electrodes was studied by microscopic techniques and two phases were observed in the electrodes: (1) a bright metallic phase constituted of small nickel grains that acts as conductor, and (2) the main hydroxide phase of the active electrodes into which the nickel grains are dispersed. The disaggregation of the electrode particles from the supporting plates was easily obtained during the dismantling procedures, indicating that a substantial percentage of the electrodes can be efficiently separated by wet sieving after shredding the spent batteries.
本研究旨在对废旧密封式MONO型镍镉电池进行化学和物理表征，以更好地确定这些废旧产品的回收工艺。电极材料主要包含镍、镉和一些钴，约占电池重量的49%。其余成分是外壳的钢制部件和含有铁和镍的支撑格栅（40%）、电解质（9%）以及塑料部件（2%）。元素定量分析表明，电极中金属高度富集。通过X射线粉末衍射结合化学分析和浸出试验进行的物相鉴定，使作者得以确定电极材料的组成如下：阴极：28.7%金属镍、53.3%氢氧化镍、6.8%氢氧化镉和2.8%氢氧化钴；阳极：39.4%金属镍和57.0%氢氧化镉。通过显微镜技术研究了电极的形态，在电极中观察到两个相：（1）由小镍颗粒构成的明亮金属相，作为导体；（2）活性电极的主要氢氧化物相，镍颗粒分散在其中。在拆解过程中，电极颗粒很容易从支撑板上分离下来，这表明在将废旧电池粉碎后，通过湿筛法可以有效地分离出相当比例的电极。
