Elektrokemijsko ožičeni titanati za litij ionske baterije (povzetek doktorske disertacije) / Electrochemically wired cathode titanates for Li-ion batteries

Mirjana Küzma, Janko Jamnik in Miran Gaberšček

 

 

Povzetek: Katodni materiali Li2MTiO4, kjer je M = Fe, Mn in Ni, so bili sintetizirani po modificiranem citratnem sol-gel postopku. Vsi trije kristalizirajo v kubični strukturi s popolnim kationskim neredom in prostorsko skupino Fm3m. Pokazana je elektrokemijska aktivnost in cikliranje za Li2FeTiO4 (LFT), Li2MnTiO4 (LMT) in Li2NiTiO4 (LNT) material in izmerjene so elektronske prevodnosti vseh treh zgoraj omenjenih materialov na zraku in v atmosferi argona. Mehanizem iz-gradnje in vgradnje litija iz in v strukturo za vse tri titanatne materiale je bil preverjen s pomočjo in-situ strukturnih tehnik (XRD, XAS, XPS).
Ključne besede: Litijev ionski akumulator; katoda; Litij-železov titanat; Litij-manganov titanat; Litij-nikljev titanat; plašč ogljika; in-situ strukturne metode

Abstract: Cathode materials Li2MTiO4, where M = Fe, Mn and Ni, were synthesized via modified citrate sol-gel procedure. Three members of the titanate cathode family crystallize in the cation disorder cubic rock-salt structure with a space group Fm3m. We demonstrate, for the first time, a considerable electrochemical activity of all three members of lithium transition-element titanates: Li2FeTiO4, Li2MnTiO4 and Li2NiTiO4. We also show their rate performance, cyclability and electronic conductivity in air and argon atmosphere. An effort has been made to understand the lithium exchange mechanism on electrochemical cycling of all three analogues and for this purpose structural in-situ techniques such as X-ray powder diffraction, Mössbauer, XAS and PES spectroscopies were used.
Keywords: Li-ion battery; cathode material; lithium iron titanate; lithium manganese titanate; lithium nickel titanate; in-situ structural methods