Fast-charging of Lithium Iron Phosphate battery with ohmic-drop compensation method: Ageing study

A fast charge with ohmic drop compensation method is carried out on commercial lithium-ion cells to address performance losses. High charging rates are used with an extended constant current period thanks to a higher limit voltage based on the ohmic-drop compensation principle. Ageing effects are characterized on cells charged with fast-charging with ODC as well as with the standard Constant Current-Constant Voltage (CC-CV) at the begin of life and at the end of life. During fast charge with ODC, the cells are degraded by cycling due to both the high temperature increases and the high cell voltage reached at the end of the CC stage. X-ray tomography and post mortem analysis reveal jelly-roll deformations and delaminations of the graphite electrode leading to loss of active materials. The degradation of the graphite electrode as well as the liquid electrolyte components is identified leading to loss of lithium inventory.