A Study on the Cause of Deterioration in Float-Charged Lithium-Ion Battery

Abstract

A lithium-ion battery composed of manganese spinel as the cathode material was tested by float charging. As a result, the capacity deterioration of the anode was greater than that of the cathode. The reduction of battery capacity is bigger than the capacity reduction supposed to be due to deterioration of the electrodes themselves, and it thought to be caused by disturbance of the lithium-ion balance, that is, a decrease in the amount of mobile lithium ions. Furthermore according to the results of the analysis of the anode, manganese is deposited on the anode, and it is thought that this deposition causes the disturbance of the lithium-ion balance. However, the capacity reduction cannot be explained by the manganese deposition alone; that is, it is supposed that a side reaction related to the deposited manganese that accompanies the loss of electric charge must be occurring at the anode as well.