ldentifying the second l phase Chemical de/lithiation with X-ray diffraction Lio.osFePO4 人 LiFePO uolesulep !7 Lio.62FePO Li insertion Lio3FePO4 wM LIFePO i乱k 15 20 25 30 35 40 45 20 25 30 35 40 45 2-Theta(Cu Ko) 2-Theta(Cu Ka) +FePO4 o:LiFePO4 8Chemical de/lithiation with X-ray diffraction Identifying the second phase Li deinsertion Li insertion +: FePO4 O: LiFePO4 8