Float Charging Performance of Lithium Ion Batteries with LiFePO₄ Cathode

抄録

We performed a long-term test to determine the float charging durability of prismatic cells with Mn containing LiFePO₄-based cathode material at various temperatures. The cell maintained more than 70% of its initial discharge capacity after float charging at 4.0 V and 25°C for 24 months. In contrast, the capacity decreased rapidly in a few months for a cell float charged at 55°C. To investigate the capacity fading mechanisms, we analyzed the cathode and the anode sheets removed from the prismatic cell used for the float charging test at 55°C with electrochemical, XRD and EPMA techniques.