Soft X-ray XANES studies of various phases related to LiFePO4 based cathode materials

摘要: LiFePO4 has been a promising cathode material for rechargeable lithium ion batteries. Different secondary or impurity phases, forming during either synthesis subsequent redox process under normal operating conditions, can have significant impact on the performance of electrode. The exploration electronic and chemical structures phases is crucial to understand such influence. We embarked series synchrotron-based X-ray absorption near-edge structure (XANES) spectroscopy studies element speciation in various phase materials relevant Li In present report, soft-X-ray XANES spectra K-edge, P L2,3-edge, O K-edge Fe L2,3-edge obtained crystalline, disordered amorphous forms some possible “impurities”, including LiPO3, Li4P2O7, Li3PO4, Fe3(PO4)2, FePO4, Fe2O3. results indicate that each from different pure reference compounds exhibits unique spectral features terms energy position, shape intensity resonances its XANES. addition, inverse partial fluorescence yield (IPFY) reveals surface vs. bulk property specimens. Therefore, data provided here be used as standards future composition analysis.