title: What Happens to LiMnPO4 upon Chemical Delithiation?
abstract: Olivine MnPO4 is the delithiated phase of the lithium-ion-battery cathode (positive electrode) material LiMnPO4, which is formed at the end of charge. This phase is metastable under ambient conditions and can only be produced by delithiation of LiMnPO4. We have revealed the manganese dissolution phenomenon during chemical delithiation of LiMnPO4, which causes amorphization of olivine MnPO4. The properties of crystalline MnPO4 obtained from carbon-coated LiMnPO4 and of the amorphous product resulting from delithiation of pure LiMnPO4 were studied and compared. The phosphorus-rich amorphous phases in the latter are considered to be MnHP2O7 and MnH2P2O7 from NMR, X-ray absorption spectroscopy, and X-ray photoelectron spectroscopy analysis. The thermal stability of MnPO4 is significantly higher under high vacuum than at ambient condition, which is shown to be related to surface water removal.
authors.forename: Yiqing
authors.initials: Y
authors.lastname: Huang
authors.forename: Natasha A
authors.initials: NA
authors.lastname: Chernova
authors.forename: Qiyue
authors.initials: Q
authors.lastname: Yin
authors.forename: Qi
authors.initials: Q
authors.lastname: Wang
authors.forename: Nicholas F
authors.initials: NF
authors.lastname: Quackenbush
authors.affiliation: Department of Chemistry, University of Cambridge , Lensfield Road, Cambridge CB2 1EW, United Kingdom.
authors.forename: Michal
authors.initials: M
authors.lastname: Leskes
authors.forename: Jin
authors.initials: J
authors.lastname: Fang
authors.forename: Fredrick
authors.initials: F
authors.lastname: Omenya
authors.forename: Ruibo
authors.initials: R
authors.lastname: Zhang
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Wahila
authors.forename: Louis F J
authors.initials: LF
authors.lastname: Piper
authors.forename: Guangwen
authors.initials: G
authors.lastname: Zhou
authors.affiliation: Department of Chemistry, University of Cambridge , Lensfield Road, Cambridge CB2 1EW, United Kingdom.
authors.forename: Clare P
authors.initials: CP
authors.lastname: Grey
authors.forename: M Stanley
authors.initials: MS
authors.lastname: Whittingham