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

• 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

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钙热还原和助熔剂的方法来再生废旧充电电池中的Ni-H正极活性物质的有效工艺。为开发该工艺，研究了以钙为还原剂的废电池中稀土氧化物(RE_2O_3)直接合成Ni-RE(稀土)储氢合金的反应机理和工艺因素对反应的影响。还研究了稀土与CaO或MgO在B2O_3基助熔剂中的溶解情况，以寻找熔剂法制备Ni-RE合金的最佳工艺条件。结果表明，在90 0℃下，当Ca当量为1.5时，Ni-RE合金的钙热还原反应在很短的时间内即可完成。PCT测试表明，合成的合金颗粒具有与商品Ni-RE储氢合金基本相同的吸氢性能。在1350℃下熔炼4h，可将合成合金中钙和氧的含量分别从0.5wt%和1.2wt%降至0.1wt%和0.3wt%。实验测定了B_2O_3-CaO-RE_2O_3(RE：La和ND)和B_2O_3-Mg O-RE_2O_3体系在1350℃时的相图。结果表明，无论是镁-B_2O_3基熔剂还是CaP-B_2O_3基熔剂，都能有效地熔化稀土氧化物。

项目成果

Hector M.Henao: "Phase Equilibrium between Ni-S Melt and FeOx-SiO_2 or FeOx-CaO Slag under Controlled Partial Pressures"Mater. Trans., JIM. Vol.43,No.9. 2219-2227 (2002)

Hector M.Henao：“受控分压下 Ni-S 熔体与 FeOx-SiO_2 或 FeOx-CaO 渣之间的相平衡”材料。

Christina Wedel: "High Temperature Phase Relations in the Ternary Ga-Mn-Ni System"J. Phase Equilibria. Vol.22,No.3. 324-330 (2001)

Christina Wedel：“三元 Ga-Mn-Ni 体系中的高温相关系”J。

Hector M. Henao: "Phase Equilibrium between Ni-S Melt and FeOx-SiO_2 or FeOx-CaO Slag under Controlled Partial Pressures"Mater, Trans. JIM. Vol.43, No.9. 2219-2227 (2002)

Hector M. Henao：“受控分压下 Ni-S 熔体与 FeOx-SiO_2 或 FeOx-CaO 渣之间的相平衡”，Mater，Trans。

Christina Wedel: "Temperature Phase Relations in the Ternary Ga-Mn-Ni System"J. Phase Equilibria. Vol.22, No.3. 324-330 (2001)

Christina Wedel：“三元 Ga-Mn-Ni 体系中的温度相位关系”J。

Hector M. Henao: "Phase Equilibrium between Ni-S Melt and CaO-Al_2 Based Slag in CO-CO_2-SO_2 Gas Mixtures at 1773K"Mater, Trans. JIM. Vol.43, No.11. 2873-2879 (2002)

Hector M. Henao：“1773K 下 CO-CO_2-SO_2 气体混合物中 Ni-S 熔体和 CaO-Al_2 基渣之间的相平衡”Mater，Trans。