scholarly journals Influence of Al2O3 Coatings on HF Induced Transition Metal Dissolution from Lithium-Ion Cathodes

Author(s):  
Yonas Tesfamhret ◽  
Reza Younesi ◽  
Erik J. Berg

Abstract Transition metal (TM) dissolution from oxide cathode materials is a major challenge limiting the performance of modern Li-ion batteries. Coating the cathode materials with thin protective layers has proved to be a successful strategy to prolong their lifetime. Yet, there is a lack of fundamental understanding of the working mechanisms of the coating. Herein, the effect of the most commonly employed coating material, Al2O3, on suppressing hydrofluoric acid(HF)-induced TM dissolution from two state-of-the-art cathode materials, LiMn2O4 and LiNi0.8Mn0.1Co0.1O2, is investigated. Karl Fischer titration, fluorine selective probe and inductively coupled plasma optical emission spectrometry are coupled to determine evolution of H2O, HF and TM concentrations, respectively, when the active materials come in contact with the aged electrolyte. The coating reduces the extent of TM dissolution, in part due to the ability of Al2O3 to scavenge HF and reduce the acidity of the electrolyte. Delithiation of the cathode materials, however, increase the extent of TM dissolution, likely because of the higher vulnerability of surface TMs in +IV oxidation state towards HF attack. In conclusion, the current study evidences the important role of acid-base reactions in governing TM dissolution in Li-ion batteries and shows that coatings protect the cathode towards an acidic electrolyte.

RSC Advances ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 7083-7091
Author(s):  
Constantin Lürenbaum ◽  
Britta Vortmann-Westhoven ◽  
Marco Evertz ◽  
Martin Winter ◽  
Sascha Nowak

An LA-ICP-OES method was developed and applied to investigate the transition metal dissolution in lithium batteries as well as lithium deposition e.g. in case of short circuits.


2020 ◽  
Vol 16 ◽  
Author(s):  
Diogo L. R. Novo ◽  
Priscila T. Scaglioni ◽  
Rodrigo M. Pereira ◽  
Filipe S. Rondan ◽  
Gilberto S. Coelho Junior ◽  
...  

Background: Conventional analytical methods for phosphorus and sulfur determination in several matrices present normally analytical challenges regarding inaccuracy, detectability and waste generation. Objective: The main objective is proposing a green and feasible analytical method for phosphorus and sulfur determination in animal feed. Methods: Synergic effect between microwave and ultraviolet radiations during sample preparation was evaluated for the first time for the animal feed digestion associated with further phosphorus and sulfur determination by ion chromatography with conductivity detection. Dissolved carbon and residual acidity in final digests were used for the proposed method assessment. Phosphorus and sulfur values were compared with those obtained using conventional microwave-assisted wet digestion in closed vessels associated with inductively coupled plasma optical emission spectrometry and with those obtained using Association of Official Analytical Chemists International official method. Recovery tests and certified reference material analysis were performed. Animal feeds were analyzed using the proposed method. Results: Sample masses of 500 mg were efficiently digested using only 2 mol L -1 HNO3. The results obtained by the proposed method was not differing significantly (p > 0.05) from those obtained by the conventional and official methods. Suitable recoveries (from 94 to 99%), agreement with certified values (101 and 104%) and relative standard deviations (< 8%) were achieved. Phosphorus and sulfur content in commercial products varied in a wide range (P: 5,873 to 28,387 mg kg-1 and S: 2,165 to 4,501 mg kg-1 ). Conclusion: The proposed method is a green, safe, accurate, precise and sensitive alternative for animal feed quality control.


Author(s):  
Masoud Aghahoseini ◽  
Gholamhassan Azimi ◽  
M. K. Amini

Determination of traces of Cd, Co, Cu, Mn and Pb elements in zirconium and its alloys by inductively coupled plasma optical emission spectrometry (ICP OES) suffers from severe spectral interferences...


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