锰酸锂电池中水分及产气的研究

Investigations of moisture content and gas in LiMn_2O_4 based battery

考察了不同比表面积、pH值等物性参数的锰酸锂正极材料的吸水特性影响,发现低比表面和低pH值的锰酸锂吸水性最弱。采用相同正极,不同水分含量的负极组装成5 Ah动力电池,随着内部水分含量的增大,电池55℃高温的衰减速率加大,而且水分高的电池出现严重的内部产气现象,重点对电池产生气体进行了分析,得到气体主要来自于电解液中的EC分解及DMC和EMC溶剂的挥发。

The specific surface area, pH value and other physical parameters of the lithium manganese oxide cathode materials for water absorption characteristics were examined. The absorbent was the weakest of lithium manganese with low specific surface area and low pH value. The 5 Ah power batteries were assembledled by using the same cathode and the anodes with different water content. The decay rate of battery was increased at high temperature of 55 ℃ with the increase of internal moisture content. The gas phenomenon of battery with high water was appeared seriously. The gas was analyzed. The gas was mainly got from EC decomposition in the electrolyte and DMC and EMC solvent evaporation.