Meaning
Surface-sensitive analytical techniques use X-ray irradiation of a sample to measure the kinetic energy of emitted photoelectrons to determine the chemical composition of thin films. This advanced laboratory method, known as X-Ray Photoelectron Spectroscopy, is used to analyze the surface chemistry of battery electrodes and the protective layers that form on them. Sourcing and quality teams rely on these measurements to verify the quality of active materials and to investigate the cause of failures during lifetime testing.
When a sample is irradiated with X-rays, the energy of the emitted electrons identifies the elements present and their chemical state. This analysis helps verify that the raw materials conform to safety and performance specifications.
Surface Characterisation
Analysis of the outermost layer of the electrode using this spectroscopic technique identifies the chemical composition of the solid electrolyte interphase, which is critical for cell stability. This X-Ray Photoelectron Spectroscopy measures both the elements present and their specific bonding states, such as lithium fluoride or lithium carbonate. Understanding this composition allows researchers to evaluate how effectively the electrolyte additives are protecting the electrode surfaces from continuous reaction with the electrolyte.
Material Analysis
Evaluation of the chemical state of transition metals on the electrode surfaces is the primary diagnostic function of this spectroscopic analysis. Sourcing engineers use this data to investigate degradation mechanisms like the oxidation or dissolution of metal ions during cycle life testing. By identifying changes in the surface chemistry, researchers determine whether the degradation is driven by electrolyte oxidation or active material breakdown, which guides efforts to improve the chemical formulation of the cells.
Procurement Sourcing
Procurement decisions are guided by these spectroscopic test results, which allow companies to evaluate and compare the surface stability of cells from different suppliers. Sourcing contracts often include requirements for these surface evaluations to ensure that the chemical composition of incoming materials remains consistent across batches. Identifying cells with high surface stability before assembly ensures the long-term reliability of the final battery packs, which reduces product recalls and warranty claims.
This rigorous quality control protects the financial investments of the project developer.
