TY - JOUR

T1 - The study of electrochemical Li-ion (de)insertion in the lithium tantalum phosphate bronze LiTa2 PO8 structure

AU - Skachilova, Maria G.

AU - Morkhova, Yelizaveta A.

AU - Shindrov, Alexander A.

PY - 2025/12/2

Y1 - 2025/12/2

N2 - Electrochemical Li+ (de)insertion in the lithium tantalum phosphate bronze LiTa2 PO8 structure was performed for the first time. Using density functional theory calculations, the formation energies of various Li1+x Ta2 PO8 (x = 0, 0.5, 1, and 1.5) configurations were obtained, and the most stable compositions were identified for each lithium content. The electron density of states is estimated for structures with minimum and maximum Li contents. Our analysis revealed that Li1+x Ta2 PO8 (x = 0) exhibited a band gap greater than 3 eV, consistent with its known behavior as a solid electrolyte. In contrast, Li1+x Ta2 PO8 (x = 1.5) featured a zero band gap. Then LiTa2 PO8 was successfully prepared using the solid-state synthesis method. The measured discharge/charge capacities were equal to 67 mAh g−1 (1.3 Li per f.u.) and 45 mAh g−1 (0.9 Li per f.u.), which were 88% and 60% of the theoretical values. Based on the cyclic voltammetry data, both diffusion-controlled reactions and pseudocapacitive/adsorption processes were detected. High Li+ diffusion coefficients of 5.7 × 10−10 cm2 s−1 (discharge) and 8.8 × 10−10 cm2 s−1 (charge) were established. According to ex situ X-ray powder diffraction data, Li+ (de)insertion occurred through a solid solution and a two-phase mechanism.

AB - Electrochemical Li+ (de)insertion in the lithium tantalum phosphate bronze LiTa2 PO8 structure was performed for the first time. Using density functional theory calculations, the formation energies of various Li1+x Ta2 PO8 (x = 0, 0.5, 1, and 1.5) configurations were obtained, and the most stable compositions were identified for each lithium content. The electron density of states is estimated for structures with minimum and maximum Li contents. Our analysis revealed that Li1+x Ta2 PO8 (x = 0) exhibited a band gap greater than 3 eV, consistent with its known behavior as a solid electrolyte. In contrast, Li1+x Ta2 PO8 (x = 1.5) featured a zero band gap. Then LiTa2 PO8 was successfully prepared using the solid-state synthesis method. The measured discharge/charge capacities were equal to 67 mAh g−1 (1.3 Li per f.u.) and 45 mAh g−1 (0.9 Li per f.u.), which were 88% and 60% of the theoretical values. Based on the cyclic voltammetry data, both diffusion-controlled reactions and pseudocapacitive/adsorption processes were detected. High Li+ diffusion coefficients of 5.7 × 10−10 cm2 s−1 (discharge) and 8.8 × 10−10 cm2 s−1 (charge) were established. According to ex situ X-ray powder diffraction data, Li+ (de)insertion occurred through a solid solution and a two-phase mechanism.

UR - https://www.scopus.com/pages/publications/105023437102

UR - https://www.mendeley.com/catalogue/1e8a238a-891e-3efd-a411-be318393122c/

U2 - 10.1039/d5dt02416a

DO - 10.1039/d5dt02416a

M3 - Article

C2 - 41328809

JO - Dalton Transactions

JF - Dalton Transactions

SN - 1477-9226

ER -