Speciation analysis of manganese in lithium battery electrolyte

Popular science: Analysis of manganese in the electrolyte of lithium batteries In the past 40 years, many documents have reported that manganese exists in the positive and negative electrodes, but the traditional Mn2+ theory as an important existence in the electrolyte has not been questioned, and there is no systematic in-depth study. Research report. Regarding lithium batteries, the dissolution of transition metal ions in the positive electrode has always been one of the important factors leading to the attenuation of the cycle function. In order to solve the problem of the dissolution of transition metal ions, researchers have developed a variety of methods, such as data encapsulation, doping, and HF eliminators. However, for a long time, the existence and composition mechanism of manganese in the electrolyte has not been paid satisfactory attention. Many people, including Tarascon, just reasonably believe that Mn3+ is prone to disproportionation, and the presence of manganese in the electrolyte is first of all divalent. In the past 40 years, many documents have reported that manganese exists in the positive and negative electrodes, but the traditional Mn2+ theory as an important presence in the electrolyte has not been questioned, and there is no systematic and in-depth research report. Israeli lithium battery expert Doron Aurbach (corresponding author) and others conducted a series of electrochemical experiments using lithium cobalt oxide graphite batteries in a LiPF6 (1M) electrolyte system with EC:DMCu003d1:1. Using EPR, XNEAS, ICP and other test methods, it is proved that Mn in the electrolyte is mainly in the form of Mn3+. The results of EPR combined with ICP data show that in the fully-charged state (4.2v) and low-charge state (3.0v) batteries, the trivalent manganese in the electrolyte accounts for 80%, while the trivalent manganese in the electrolyte only accounts for 60% in the cycle. %. It also proves that the disproportionation rate of Mn3+ in the organic electrolyte system is very slow. Disclaimer: Some pictures and content of the articles published on this site are from the Internet. If there is any infringement, please contact to delete. Previous: Analyze the charging principle of the battery