The report summarizes all the activities performed to design the Pilot Plant for the recycling treatment of end-of-life NAS batteries. It integrates both the preliminary results collected in the previous report and the subsequent experimental validation and economic evaluations. The report structure is the following: I.PRODUCT ANALYSIS A detailed analysis has been performed on the working mechanism, the structure and the composition of NAS cells, modules and packs in order to derive initial requirements for the disassembly procedure. The data collected in the initial phase has been integrated with the additional info provided by NGK through documents and through the visit to Japanese facilities. The investigation was aimed at highlighting the current challenges of NAS treatment in terms of defects of end-of-life cells, safety issues, residual value of involved materials, etc. II.RECYCLING PROCESS FOR MODULES The dismantling of modules represents the first task of NAS batteries disposal: the sequence of operations has been investigated starting from the current NGK procedure with the aim of analyze the possibility and degree of automation, the optimal technologies to be used and the final status of disassembled components. The collected results are preliminary and will be experimentally validated during the construction of the Pilot Plant, when end-of-life modules will be available for tests. III.RECYCLING PROCESS FOR CELLS Data on the current recycling treatments of NAS cells and on manual procedure performed at laboratory scale has been deeply analyzed to understand the potential automation of each process step and to optimize materials separation. Preliminary experiments have been performed on cells without Sodium in order to safely investigate the adhesion between components, the changes of inner structure during mechanical treatments, the required area for the operations and the possible gripping points, etc. Successively, a validation of the different disassembly strategies has been performed on charged samples thanks to the construction of an ad hoc Safety Box, i.e. a metallic structure preventing the direct contact of Sodium with uncontrolled atmosphere and ensuring the aspiration of released dusts and gases coming from mechanical operations. IV.CHEMICAL CHARACTERIZATION To understand and economically estimate the value of disassembled components, chemical analysis has been performed in order to propose feasible reuse and/or recycling strategies for each separated material. The main targets of these analyses were the Sulfuric positive electrode (sent to an external chemical laboratory to quantify metallic and Sodium residues), the ?-Alumina electrolyte (provided in small samples to potential secondary users) and small portions of metallic components to derive their composition for the smelting. V.ECONOMIC FEASIBILITY OF THE PILOT PLANT All the analysis and results obtained in the experimental campaign were finally characterized by the economical point of you. An estimation of costs given by the necessary equipment, the workforce, the space, etc. has been compared with the disposal/reuse of segregated materials in order to plan the future investments for the designed Pilot Plant.
Planning of a Sodium-Sulfur chemical battery (NAS) automated disassembly pilot plant - Final Report
Elena Mossali;Marcello Colledani
2020
Abstract
The report summarizes all the activities performed to design the Pilot Plant for the recycling treatment of end-of-life NAS batteries. It integrates both the preliminary results collected in the previous report and the subsequent experimental validation and economic evaluations. The report structure is the following: I.PRODUCT ANALYSIS A detailed analysis has been performed on the working mechanism, the structure and the composition of NAS cells, modules and packs in order to derive initial requirements for the disassembly procedure. The data collected in the initial phase has been integrated with the additional info provided by NGK through documents and through the visit to Japanese facilities. The investigation was aimed at highlighting the current challenges of NAS treatment in terms of defects of end-of-life cells, safety issues, residual value of involved materials, etc. II.RECYCLING PROCESS FOR MODULES The dismantling of modules represents the first task of NAS batteries disposal: the sequence of operations has been investigated starting from the current NGK procedure with the aim of analyze the possibility and degree of automation, the optimal technologies to be used and the final status of disassembled components. The collected results are preliminary and will be experimentally validated during the construction of the Pilot Plant, when end-of-life modules will be available for tests. III.RECYCLING PROCESS FOR CELLS Data on the current recycling treatments of NAS cells and on manual procedure performed at laboratory scale has been deeply analyzed to understand the potential automation of each process step and to optimize materials separation. Preliminary experiments have been performed on cells without Sodium in order to safely investigate the adhesion between components, the changes of inner structure during mechanical treatments, the required area for the operations and the possible gripping points, etc. Successively, a validation of the different disassembly strategies has been performed on charged samples thanks to the construction of an ad hoc Safety Box, i.e. a metallic structure preventing the direct contact of Sodium with uncontrolled atmosphere and ensuring the aspiration of released dusts and gases coming from mechanical operations. IV.CHEMICAL CHARACTERIZATION To understand and economically estimate the value of disassembled components, chemical analysis has been performed in order to propose feasible reuse and/or recycling strategies for each separated material. The main targets of these analyses were the Sulfuric positive electrode (sent to an external chemical laboratory to quantify metallic and Sodium residues), the ?-Alumina electrolyte (provided in small samples to potential secondary users) and small portions of metallic components to derive their composition for the smelting. V.ECONOMIC FEASIBILITY OF THE PILOT PLANT All the analysis and results obtained in the experimental campaign were finally characterized by the economical point of you. An estimation of costs given by the necessary equipment, the workforce, the space, etc. has been compared with the disposal/reuse of segregated materials in order to plan the future investments for the designed Pilot Plant.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
