new method is proposed for the recovery of Mn via the direct electrochemical reduction of LiMn_(2)O_(4) from the waste of lithium-ion batteries in NaCl−CaCl_(2) melts at 750°C.The results show that the LiMn_(2)O_...new method is proposed for the recovery of Mn via the direct electrochemical reduction of LiMn_(2)O_(4) from the waste of lithium-ion batteries in NaCl−CaCl_(2) melts at 750°C.The results show that the LiMn_(2)O_(4) reduction process by the electrochemical method on the coated electrode surface occurs in three steps:Mn(IV)→Mn(III)→Mn(II)→Mn.The products of this electro-deoxidation are CaMn2O4,MnO,(MnO)x(CaO)1−x,and Mn.Metal Mn appears when the electrolytic voltage increases to 2.6 V,which indicates that increasing the voltage may promote the deoxidation reaction process.With the advancement of the three-phase interline(3PI),electric deoxygenation gradually proceeds from the outer area of the crucible to the core.At high voltage,the kinetic process of the reduction reaction is accelerated,which generates double 3PIs at different stages.展开更多
Since pyrometallurgical approaches on lithium ion battery recycling are not yet capable of recovering lithium but only nickel,cobalt and manganese,the Chair of Thermal Processing Technology at the Montanuniversitaet L...Since pyrometallurgical approaches on lithium ion battery recycling are not yet capable of recovering lithium but only nickel,cobalt and manganese,the Chair of Thermal Processing Technology at the Montanuniversitaet Leoben started to investigate experimental reactor concepts on their suitability to overcome this major drawback.Therefor,the general behaviour of currently used cathode materials under reducing conditions and high temperatures is of great interest.This work expands previous performed heating microscope experiments by thermogravimetric analysis(TGA)to characterize the reactions that are responsible for certain changes in the cathode materials.By comparing the superficial changes of the samples in the heating microscope with the corresponding data from the TGA,it was possible to identify the temperature zones in which reduction reactions occured.For all investigated cathode materials,the reduction reactions started at technically feasible temperatures of approx.1000◦C,which is favorable for the desired recycling process.On the other hand,this is some hundred degrees higher than the temperature at which first changes in the heating microscope could be observed and indicates that there are changes in the material before the reduction starts.Therefore,the results also emphasize the need for further analysis to clarify this offset and to complete the thermal characterisation of the cathode materials.展开更多
基金the National Nat-ural Science Foundation of China(No.51774143).
文摘new method is proposed for the recovery of Mn via the direct electrochemical reduction of LiMn_(2)O_(4) from the waste of lithium-ion batteries in NaCl−CaCl_(2) melts at 750°C.The results show that the LiMn_(2)O_(4) reduction process by the electrochemical method on the coated electrode surface occurs in three steps:Mn(IV)→Mn(III)→Mn(II)→Mn.The products of this electro-deoxidation are CaMn2O4,MnO,(MnO)x(CaO)1−x,and Mn.Metal Mn appears when the electrolytic voltage increases to 2.6 V,which indicates that increasing the voltage may promote the deoxidation reaction process.With the advancement of the three-phase interline(3PI),electric deoxygenation gradually proceeds from the outer area of the crucible to the core.At high voltage,the kinetic process of the reduction reaction is accelerated,which generates double 3PIs at different stages.
基金the funding support of the Zukunftsfonds Steiermark with funds from the province of Styria,Austria,Grant No.GZ:ABT08-189002/2020 PN:1305.
文摘Since pyrometallurgical approaches on lithium ion battery recycling are not yet capable of recovering lithium but only nickel,cobalt and manganese,the Chair of Thermal Processing Technology at the Montanuniversitaet Leoben started to investigate experimental reactor concepts on their suitability to overcome this major drawback.Therefor,the general behaviour of currently used cathode materials under reducing conditions and high temperatures is of great interest.This work expands previous performed heating microscope experiments by thermogravimetric analysis(TGA)to characterize the reactions that are responsible for certain changes in the cathode materials.By comparing the superficial changes of the samples in the heating microscope with the corresponding data from the TGA,it was possible to identify the temperature zones in which reduction reactions occured.For all investigated cathode materials,the reduction reactions started at technically feasible temperatures of approx.1000◦C,which is favorable for the desired recycling process.On the other hand,this is some hundred degrees higher than the temperature at which first changes in the heating microscope could be observed and indicates that there are changes in the material before the reduction starts.Therefore,the results also emphasize the need for further analysis to clarify this offset and to complete the thermal characterisation of the cathode materials.
