## Abstract

Lithium diffusion in the spinel type cubic titanium disulphide (c-Li_{x}TiS_{2}, x = 0.69 and 0.75) is investigated theoretically with periodic density-functional theory (DFT) method. The calculated unit cell length and bond distances for a series of Li_{x}TiS_{2} (0 < x < 1) compounds are in agreement with the experimental data, with the maximum deviation of +0.06% for the lattice parameter and -1.2% for the bond length. In agreement with Vegard's law, the unit cell length a is an almost linear function of x. The calculated average intercalation potentials for the series Li_{x}TiS_{2} (0 < x < 1) range between 1.6 to 1.9 V which is in the range of experimental findings. Competing pathways for Li diffusion in c-Li_{x}TiS_{2} (x = 0.69 and 0.75) are investigated using the climbing-image Nudged-Elastic-Band (cNEB) approach. Li^{+} ions can migrate along the '100' and '110' directions suggesting that Li^{+} diffusion in c-Li_{x}TiS_{2} is three-dimensional (3D). The calculated activation energy values for the considered migration pathways show that Li^{+} diffusion along the '100' directions is more preferable that that along the '110' directions.

Original language | English |
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Pages (from-to) | 1265-1274 |

Number of pages | 10 |

Journal | Zeitschrift fur Physikalische Chemie |

Volume | 229 |

Issue number | 9 |

Early online date | 26 Jun 2015 |

DOIs | |

Publication status | Published - 28 Sep 2015 |

## Keywords

- Activation Energy
- cNEB Method
- Delithiation
- DFT
- Intercalation Potential
- Li Intercalation
- Li Ion Diffusion
- Lithium Titanium Disulphide
- Point Defects

## ASJC Scopus subject areas

- Physical and Theoretical Chemistry