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Insights into the Impact of Impurities and Non‐Stoichiometric Effects on the Electrochemical Performance of Li 2 MnSiO 4
Author(s) -
Fleischmann S.,
Mancini M.,
Axmann P.,
GollaSchindler U.,
Kaiser U.,
WohlfahrtMehrens M.
Publication year - 2016
Publication title -
chemsuschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.412
H-Index - 157
eISSN - 1864-564X
pISSN - 1864-5631
DOI - 10.1002/cssc.201600894
Subject(s) - impurity , stoichiometry , materials science , crystallite , electrochemistry , calcination , analytical chemistry (journal) , particle size , phase (matter) , chemical engineering , chemistry , electrode , catalysis , metallurgy , organic chemistry , engineering
A series of Li 2 MnSiO 4 samples with various Li, Mn, and/or Si concentrations are reported to study for the first time the effect of impurities and deviation from ideal stoichiometry on electrochemical behavior. Carbon‐coated and nanosized powders are obtained at 600 °C and compared with those synthetized at 900 °C. Samples are investigated using XRD, SEM, high‐resolution TEM, attenuated total reflection infrared spectroscopy and Brunauer–Emmett–Teller surface area to characterize crystal structure, particle size, impurity amount, morphology, and surface area. Electrochemical performance depends on impurities such as MnO as well as crystallite size, surface area, and non‐stoichiometric phases, which lead to the formation of additional polymorphs such as Pmnb and P 2 1 / n of Li 2 MnSiO 4 at low calcination temperatures. A systematic analysis of the main parameters affecting the electrochemical behavior is performed and trends in synthesis are identified. The findings can be applied to optimize different synthesis routes for attaining stoichiometric and phase‐pure Pmn 2 1 Li 2 MnSiO 4 as cathode material for Li‐ion batteries.