¹Uzhhorod National University, 46 Pidhirna Street, 88000 Uzhhorod, Ukraine
²Pavol Jozef Šafárik University, Park Angelinum 9, Košice 04001, Slovakia
*Corresponding author e-mail: vitaliy.bilanych@uzhnu.edu.ua

Abstract. The work investigates temperature-dependent charge accumulation and relaxation processes, as well as the current-voltage characteristics of Ag|Ag_7–x(P_xGe_1–x)S₅I|Se heterostructures with different Ge/P ratios. The current-time dependences I(t) were studied in a potentiostatic mode (0.4 V, 600 s) followed by discharge (0 V, 600 s) at 20 °C and 60 °C. It is shown that the relaxation is described by a bi-exponential model with time constants τ₁ and τ₂, corresponding to fast interfacial and slow diffusion processes, respectively. It was established that with increasing temperature, the relaxation times decrease due to the activation of Ag⁺ ion transport and the softening of selenium. Arrhenius analysis revealed different activation energies for the fast (~ 0.1…0.3 eV) and slow (~ 0.05…0.15 eV) processes. The current-voltage characteristics exhibit nonlinear and asymmetric behavior with current maxima associated with interfacial polarization and the formation of Ag₂Se. The minimum relaxation times are observed for the composition Ag_6.5P_0.5Ge_0.5S₅I.

Keywords: superionic conductors, argyrodite structure, Ag_7–x(P_xGe_1–x)S₅I, solid electrolyte heterostructures, charge-discharge processes, interfacial polarization, solid-state electrochemical devices.

Full Text (PDF)

Cite: BibTex

Cite: RIS

Back to Volume 29 N2