Nanoscale spinel LiFeTiO₄for intercalation pseudocapacitive Li⁺storage

Abstract

Intercalation pseudocapacitive Li(+) storage has been recognized recently in metal oxide materials, wherein Li(+) intercalation into the lattice is not solid-state diffusion-limited. This may bridge the performance gap between electrochemical capacitors and battery materials. To date, only a few materials with desired crystal structure and with well-defined nanoarchitectures have been found to exhibit such attractive behaviour. Herein, we report for the first time that nanoscale spinel LiFeTiO4 as a cathode material for Li-ion batteries exhibits intercalation pseudocapacitive Li(+) storage behaviour. Nanoscale LiFeTiO4 nanoparticles with native carbon coating were synthesized by a sol-gel route. A fast and large-amount of Li(+) storage (up to 1.6 Li(+) per formula unit over cycling) in the nanoscale LiFeTiO4 host has been achieved without compromising kinetics.

Li+ intercalation in isostructural Li2VO3 and Li2VO2F with O2− and mixed O2−/F− anions

“…The random cationic distribution in the DRS phase is responsible for the large distribution of chemical shifts and the broad 7 Li signal, 35 as also observed for Li 2 VO 2 F. 18 Li species in the amorphous LiVO 3 cannot be resolved. The random cationic distribution in the DRS phase is responsible for the large distribution of chemical shifts and the broad 7 Li signal, 35 as also observed for Li 2 VO 2 F. 18 Li species in the amorphous LiVO 3 cannot be resolved.…”

Lithiation-driven structural transition of VO2F into disordered rock-salt LixVO2F

“…It is considered that the increased capacity at low voltage may arise from an enhanced intercalation process. 20,54 Moreover, based on the calculated composition of Li1.67VO2F at the end of the second discharge, it is considered that further lithium intercalation (with x > 1.67) into disordered rock-salt lattice (with about 16% cation sites unoccupied) may occur at lower discharge cutoff voltages (below 1.3 V).…”

Layered metal vanadates with different interlayer cations for high-rate Na-ion storage

“…[16][17][18] Among them, layered metal vanadates have been proved to show intercalation pseudocapacitive behaviors due to their large open channels within the framework of the crystal structure, which offer spacious pathways for the insertion and extraction of the alkali metal ions. [19][20][21][22][23][24][25][26] Besides, they show small volume changes during Na + insertion [27][28][29] and high rate capability even when the particle size is at the level of micrometers, which is especially benecial for practical applications. 27,28,30 In a previous report, we showed that the fast Na-ion diffusion in zinc vanadate leads to high-rate Na-ion storage capability.…”