Zero-strain strategy incorporating TaC with Ta₂O₅ to enhance its rate capacity for long-term lithium storage

Abstract

Ta2O5 holds great potential for lithium storage due to its high theoretical capacity and long-life cycling. However, it still suffers from unsatisfactory rate capability because of its low conductivity and...

Computational Design of Cation-Disordered Li3Ta2O5 with Fast Ion Diffusion Dynamics and Rich Redox Chemistry for a High-Rate Li-Ion Battery Anode Material

“…Such straightforward transport paths found in DRX-Li 3 Ta 2 O 5 and DRX-Li 3 Nb 2 O 5 geometries are less complex than those reported in DRX-Li 3 V 2 O 5 , 15,17 lithium titanate, 52 and Wadsley−Roth crystallographic shear structures. 46 To confirm what has been described above, we employ BVSE modeling to guess the initial and final sites of minimal energies and different local environments (Figures 4 and S3).…”

“…Upon battery operation, a detrimental chemical conversion (phase decomposition) could be occurred, which results in capacity loss . Since amorphous Ta 2 O 5 has been experimentally used as a conversion anode and can interact with Li + through complex chemical reactions, we compute the possible Li intercalation/conversion energies in Ta 2 O 5 structures according to the following chemical reactions The computed intercalation energy from GGA is −3.95 eV/f.u, while the conversion energies from eqs and are +7.41 and −2.39 eV/f.u, respectively. To correct the self-interaction error, especially for conversion reaction where the oxidation states of Ta atoms are not the same in the reactants and products, we further use GGA + U with U Ta = 1.35 eV; , the intercalation energy is calculated to be −3.78 eV, and the corresponding conversion energies are +7.57 and −2.19 eV; they are quite close to the GGA results, and the conversion (decomposition) pathway described by eq is energetically more favorable than that by eq .…”

“…Upon battery operation, a detrimental chemical conversion (phase decomposition) could be occurred, which results in capacity loss . Since amorphous Ta 2 O 5 has been experimentally used as a conversion anode and can interact with Li + through complex chemical reactions, we compute the possible Li intercalation/conversion energies in Ta 2 O 5 structures according to the following chemical reactions Ta 2 normalO 5 + 3 Li + + 3 normale − ↔ Li 3 Ta 2 normalO 5 goodbreak0em1em⁣ ( intercalation ) Ta 2 normalO 5 + 3 Li + + 3 normale − ↔ 2 TaO + 3 LiO goodbreak0em1em⁣ ( conversion ) Ta 2 normalO 5 + 3 Li + + 3 normale − ↔ 2 LiTaO 2 + LiO goodbreak0em1em⁣ ( conversion ) The computed intercalation energy from GGA is −3.95 eV/f.u, while the conversion energies from eqs and are +7.41 and −2...…”

Facile synthesis of V4+-doped and graphene-decorated V2O5/biomass carbon nanocomposite using graphene quantum dots for supercapacitors with wide voltage window and high energy density

“…Ta 2 O 5 can offer high specific capacitance due to multiple redox states and long cycling life due to its high structural stability, but the low inherent electronic conductivity limits its high-rate capacity. 15 V 2 O 5 has received more attention in high-performance supercapacitors because of multiple states. However, V 2 O 5 suffers from low electrical conductivity and cycling stability.…”