ORIGINAL ARTICLE CHARACTERISTIC INVESTIGATIONS OF A COMMERCIAL CYLINDRICAL-TYPE LITHIUM-ION BATTERY

Abstract

A commercial 4000 mAh cylindrical 26650-type lithium-ion battery was
disassembled for the purpose of studying the electrode materials that defines the electrochemical performance of the battery. The cathode material is found to be a mixture of LiM2O4 and LiMO2 oxides (M = Mn, Co, Ni, Al or its combinations) and the anode material is dominated by graphite. The cathode materials composes of the homogeneous particles with mean diameter of 1 to 3 µm meanwhile the mean diameter of the graphite particles is about 10 µm. The first discharge capacity of the battery is 3820 mAh, which accounted for approximately 95.5% of the nominated capacity. The discharge capacity is gradually decreases during cycling. The average discharge voltage plateau is approximately 3.7 V, which is identical with the rated working voltage battery