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Preparation and re‐examination of Li 4 Ti 4.85 Al 0.15 O 12 as anode material of lithium‐ion battery
Author(s) -
Cai Rui,
Yuan Tao,
Ran Ran,
Liu Xiaoqin,
Shao Zongping
Publication year - 2011
Publication title -
international journal of energy research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.808
H-Index - 95
eISSN - 1099-114X
pISSN - 0363-907X
DOI - 10.1002/er.1741
Subject(s) - calcination , spinel , doping , crystallite , materials science , lithium ion battery , inorganic chemistry , lithium (medication) , oxide , dopant , analytical chemistry (journal) , chemistry , battery (electricity) , metallurgy , catalysis , medicine , biochemistry , power (physics) , physics , optoelectronics , quantum mechanics , chromatography , endocrinology
Spinel‐type Al 3+ ‐doped Li 4 Ti 5 O 12 oxide with the nominal composition of Li 4 Ti 4.85 Al 0.15 O 12 was synthesized by a cellulose‐assisted glycine–nitrate combustion process at reduced temperatures. X‐ray diffraction characterization demonstrated that all Al 3+ was successfully incorporated into the spinel lattice structure after calcination at 700°C. The Al 3+ doping did not have obvious effect on the phase formation and phase structure while it led to an increase in surface area and a decrease in crystallite size of the oxide. The discharge capacity, the rate performance and the cycling stability were all slightly improved after the Al 3+ doping. First discharge capacity ∼221 mAh g −1 was achieved for the as‐synthesized Li 4 Ti 4.85 Al 0.15 O 12 from calcination at 700°C, higher than 189 mAh g −1 for the pristine Li 4 Ti 5 O 12 prepared by the same way. Al 3+ was likely incorporated into both Li + tetrahedral site and Ti 4+ octahedral site with the majority into the Ti 4+ site. Al 3+ doping into the Li + tetrahedral site increased the reducibility of Ti 4+ ; consequently comparable electronic conductivity was observed for Li 4 Ti 5 O 12 and Li 4 Ti 4.85 Al 0.15 O 12 after the reduction. However, it also induced a decrease of lithium‐ion diffusion coefficient and a transition of rate‐limiting step of the electrode reaction from electron charge transfer for Li 4 Ti 5 O 12 to Li + diffusion for Li 4 Ti 4.85 Al 0.15 O 12 . The improved performance from the Al 3+ doping was mainly attributed to the increased surface area of the oxide. Copyright © 2010 John Wiley & Sons, Ltd.