Li₄Ti₅O₁₂-based anode materials with low working potentials, high rate capabilities and high cyclability for high-power lithium-ion batteries: a synergistic effect of doping, incorporating a conductive phase and reducing the particle size

Abstract

Fe2+/Cr3+ doped LTO/MWCNT composites were made by combining doping, compositing and particle-size reduction, and exhibit improved electrochemical performances.

Advanced composites of complex Ti-based oxides as anode materials for lithium-ion batteries

“…In this review, recent progress made in advanced composites of complex Ti-based oxide anode materials (including Li 4 Among the complex Ti-based oxides, Li 4 Ti 5 O 12 has probably received the most attention due to its outstanding features in terms of stable voltage plateau, good safety performance, long cyclic stability, and easy fabrication [24]. Li 4 Ti 5 O 12 was firstly introduced by Ferg et al in 1994 [25], then extensively studied.…”

Li5Cr9Ti4O24: A new anode material for lithium-ion batteries

“…For Li 5 The electronic conductivity of Li 5 Cr 9 Ti 4 O 24 was determined by a two-probe direct current method. It exhibits a large electronic conductivity of 2.70×10 -6 S cm -1 , which is at least seven orders of magnitude larger than that of Li 4 Ti 5 O 12 (<10 -13 S cm -1 ) [10] and even about two orders of magnitude larger than those of Ni 2+ , Cu 2+ , Fe 2+ , Cu + , Al 3+ , Ta 5+ , Ga 3+ and Co 3+ doped Li 4 Ti 5 O 12 (10 -9 -10 -7 S cm -1 ) [3,4,11,12]. Previous studies show that the electronic conduction in spinel oxides containing transition metal ions is dominated by the localized d electrons hopping among the octahedral (16d) cations [13][14][15][16].…”

“…Intensive research on the improvement of its conductivity has been carried out. After modified by doping with foreign ions, compositing a second conductive phase and/or reducing the particle size, it can exhibit improved electronic conductivity and Li + ion diffusion coefficient, resulting in its high rate performance [3,4]. However, to our best knowledge, no studies on the increase of its theoretical capacity have been reported so far.…”

“…Thus, the significantly larger Li + ion diffusion coefficient in Li 5 Cr 9 Ti 4 O 24 can be achieved. [3,4,18]. During the electrochemical reaction of an LIB, electrons and Li + ions simultaneously transport in active material particles in order to achieve charge neutrality.…”

Modification of lithium titanate spinel by d-electron metals

“…Furthermore, spinel Li4Ti5O12 shows a very small volume variation during the charge/discharge process, consequently resulting in excellent cycle stability. Due to this fact, numerous researchers have been trying to improve its transport properties, by going to nanoscale [7,[14][15][16][17][18][19][20] or/and doping [21][22][23][24][25][26][27]. The second way is to dope with cations/anions in Li, Ti or O site; modification with d-electron metal could enhance electronic conductivity and reduce the electrode polarization.…”