Theoretical study of cation doping effect on the electronic conductivity of Li₄Ti₅O₁₂

Abstract

The electronic band structures of pristine and Cr-, Fe-, Ni-or Mg-doped Li 4 Ti 5 O 12 have been calculated by first-principles local-density calculations. Analysis is carried out for the band gaps and density of states of these materials. It is shown that Cr or Mg doping can improve the electronic conduction of Li 4 Ti 5 O 12 , but Ni or Fe doping does not have such an effect. The mechanism for the improved electronic conduction is also proposed.

Cr Doping of Li4Ti5O12 by Sol-Gel Method for High Power Lithium-Ion Batteries

“…The Cr-doped Li 4 Ti 5 O 12 (denoted as LTO as usual) samples were synthesized via a sol-gel route. F127, a kind of nonionic surfactant (EO) 106(PO) 70(EO) 106 tri-block copolymer, was used as chelating agent.…”

“…A main drawback, however, is that its electronic conductivity is very low because of its intrinsically wide band gap of about 2 eV. [4][5][6] Various ways have been taken to increase the performance of Li 4 Ti 5 O 12 experimentally and theoretically. High temperature solid-phase method failed to make nanomaterials, but sol-gel did the good job.…”

“…Li 4 Ti 5 O 12 has attracted attention on account of its high potential (1.55 V), which provides good stability, and its zero-strain characteristics, which allows high-speed charging and discharging. [1][2][3] Compared with carbon negative-electrode materials, it can improve the rate capability and cycling life.…”

“…[25][26][27][28][29] Among these research, sol-gel interested us because it can effectively smaller the particle size. Cr 3+ was been explored mostly because it can be well inserted into the crystal structure of Li 4 Ti 5 O 12 . [30][31][32] The current paper presents a combined way to obtain modified Li 4 strong acid and the mixed gel was dried at 60 cent degree and calcined in air atmosphere.…”

“…Cr 3+ was been explored mostly because it can be well inserted into the crystal structure of Li 4 Ti 5 O 12 . [30][31][32] The current paper presents a combined way to obtain modified Li 4 strong acid and the mixed gel was dried at 60 cent degree and calcined in air atmosphere. X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) were used to characterize the physical properties, and cyclic voltammetry, charge/discharge test were used to investigate the electrochemical behavior of it.…”