Meaning
Analytical measurement that determines the energy required to remove an electron from the oxygen 1s shell, used to identify the chemical state of oxygen atoms on the electrode surface. In lithium ion batteries, measuring the XPS O1s binding energy helps researchers analyze the composition of the solid electrolyte interphase layer and surface functional groups. This measurement is performed using X-ray photoelectron spectroscopy, providing sub nanometer depth resolution of the electrode’s outer chemical layer.
Surface Analysis
Inorganic and organic oxygen species are distinguished by their specific peak positions in the photoelectron spectrum. The surface analysis of the cycled electrode reveals the formation of lithium carbonates or organic polymer species. This peak shifting indicates changes in the surface chemical bonds.
Sourcing Validation
Precursor oxygen content is monitored to ensure consistent starting materials for the anode fabrication. The sourcing validation of the carbon precursor relies on these binding energy signatures to verify that the carboxyl and carbonyl groups have been successfully removed. Consistent surface chemistry prevents parasitic electrolyte reactions.
Cell Degradation
Electrolyte decomposition products build up on the cathode and anode surfaces during cycling. The cell degradation of the battery can be tracked by observing the growth of specific oxygen peaks over time. Monitoring these chemical changes helps engineers design more stable electrolyte formulations.
