Regeneration of the Ni-H Cathode Active Material in Rechargeable Battery by Calciothermic Reduction Flexing Process

热还原弯曲法再生充电电池中镍氢正极活性物质

基本信息

批准号：
13555204
负责人：
ITAGAKI Kimio
金额：
$ 3.71万
依托单位：
Tohoku University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2001
资助国家：
日本
起止时间：
2001 至 2002
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-13555204/
关键词：
rechargeable battery Ni-H cathode active material recyde calciothermic reduction process fluxing process Ni-RE hydrogen storage alloy B_2O_3-CaO-RE_2O_3 System B_2O_3-MaO-RE_2O_3 systems B_2O_3-CaO-R_2O_3系

项目摘要

The investigators have proposed an efficient process to regenerate the Ni-H cathode active material in the spent rechargeable battery by using calciothermic reduction and fluxing methods. to develop the proposed process, the reaction mechanism and the effect of process factors in the calciothermic reduction method to directly synthesize the Ni-RE(rare earth) hydrogen storage alloy from the rave earth oxide (RE_2O_3) in the spent battery with calcium as a reductant were investigated in the present study. Solubility of RE_2O_3 and CaO or MgO in the B_2O_3 base flux was also investigated to look for the optimum condition in the fluxing method to synthesized Ni-RE alloy from the residual RE_2O_3 and CaO or MgO.It was found that calciothermic reduction and the resultant formation of Ni-RE alloy were completed in a very short time of 30min with 1.5 equivalents of Ca at 900℃. The PCT measurement has clarified that the synthesized alloy particles have the hydrogen-absorbing properties which are nearly same as those of commercial Ni-RE hydrogen storage alloys. The contents of calcium and oxygen in the synthesized alloy could be decreased from 0.5 and 1.2 wt% to 0.1 and 0.3wt%, respectively, by melting for 4 hrs at 1350℃.Phase diagrams for the B_2O_3-CaO-RE_2O_3(RE: La and Nd) and B_2O_3-MgO-RE_2O_3 systems were experimentally determined at 1350℃ It was clarified that the solid phase equilibrating with the liquid phase is a RE_2O_3-B_2O_3 compound with a mole ratio of 1/1 without CaO or MgO. Both of the MgO-B_2O_3 and CaP-B_2O_3 base fluxes were found to be amenable for efficiently fluxing the rare earth oxides.

研究人员提出了一种利用热热还原和助熔方法再生废可充电电池中镍氢正极活性材料的有效工艺，并研究了该工艺、反应机理以及工艺因素对热热还原法的影响。本研究以废电池中的稀土氧化物(RE_2O_3)为原料，以钙为还原剂，直接合成Ni-RE(稀土)储氢合金。还研究了B_2O_3基熔剂中的RE_2O_3和CaO或MgO，以寻找熔剂法中残留RE_2O_3和CaO或MgO合成Ni-RE合金的最佳条件。结果发现，热热还原反应生成Ni -RE合金在900℃下用1.5当量的Ca在很短的30分钟内完成。PCT测量表明，合成的合金颗粒具有与商业Ni-RE储氢合金几乎相同的吸氢性能，合成合金中钙和氧的含量可以从0.5和1.2wt%降低到0.1和0.3wt%。分别在1350℃下熔化4小时。B_2O_3-CaO-RE_2O_3的相图（RE：La和Nd）在1350℃下对B_2O_3-MgO-RE_2O_3体系进行实验测定，结果表明与液相平衡的固相是摩尔比为1/1的RE_2O_3-B_2O_3化合物，不含CaO和MgO-B_2O_3。和 CaP-B_2O_3 基础助焊剂被发现适合有效地助焊剂稀土氧化物。