Scanning spreading resistance characterization of aged Li-ion batteries using atomic force microscopy

Investigation of aging mechanisms in lithium-ion batteries is very challenging, as aging is a cascading effect of various physical and chemical processes. As the cell ages, its impedance increases, which can be attributed to the increase in the surface resistance of the anode/cathode. We demonstrate the use of scanning spreading resistance microscopy for measuring the change in the surface resistance of LiFePO4 cathode as a result of aging. We propose a mechanism leading to an increase in the surface resistance.