Solid electrolytes based on lithium-containing lanthanum metaniobates and metatantalates with defect-perovskite structure

Abstract

Abstract. The structure and transport properties of lithium-containing lanthanum metaniobates and metatantalates with defect-perovskite structure, Laz,3.~Li3x~4.3__,xNb [Ta]206, have been studied. It has been shown that the materials under investigation possess a high lithium ion-conductivity

Cation ordering in A-site-deficient Li-ion conducting perovskites La(1−x)/3LixNbO3

“…[3][4][5][6][7][9][10][11] End members such as Th 0.33 NbO 3 and La 0.33 NbO 3 (LNO) have crystal structures with two-thirds of A sites occupied by RE atoms in the A1 layer (vacancy-poor layer) and all A cages empty in the A2 (vacancyrich) layer, as illustrated in Fig. [3][4][5][6][7][9][10][11] End members such as Th 0.33 NbO 3 and La 0.33 NbO 3 (LNO) have crystal structures with two-thirds of A sites occupied by RE atoms in the A1 layer (vacancy-poor layer) and all A cages empty in the A2 (vacancyrich) layer, as illustrated in Fig.…”

Peculiarities of the Synthesis of Lithium Ion Conducting Lanthanum Tantalate by Solid‐State Reaction and Precipitation from Solutions

“…The observed considerable increase in the rate of chemical processes, when using the (PS) synthesis method, is because of the larger surface energy of the (LLTaO) PS powder and hence to a greater reactivity of the precursors. The Fullprof Rietveld analysis of the patterns collected from (SSR) [21] as well as from (PS) sintering samples indicated the formation of the defect-perovskite structure with tetragonal symmetry and the lattice parameters: a = b = 3.903 Å, c = 7.831 Å, V = 119.29 Å 3 and a = b = 3.896 Å, c = 7.826 Å, V = 118.79 Å 3 , respectively.…”

“…Therefore, its appearance at a lower temperature (1220 K) in lithium-containing samples is probably due to the decomposition of La 3 TaO 7 as expressed by Equation (8). [14] At 1220 K, LiTaO 3 from Equation (6) (9), (10) and (11).…”

“…The synthesis and pellet sintering procedures have been described previously in detail. [7,8] To synthesize (Li 3x La 2/3-x v 4/3-2x )Ta 2 O 6 (3x = 0.5) by the PS method, alcoholic solutions of extra pure La(NO 3 ) 3 and TaCl 5 and aqueous solutions of LiOH and NH 4 OH were used. The NH 4 OH solution was added, at pH 9, to the mixture of La(NO 3 ) 3 and TaCl 5 solutions, taken in a stoichiometric ratio.…”

“…The crystallographic structure and transport properties of these tantalates prepared by solid-state reactions have already been studied. [4][5][6][7][8] However, the details and peculiarities of the different chemical reactions and phase transformation occurring during the synthesis of the lanthanum tantalate (La 2/3 v 4/3 )Ta 2 O 6 and the lithiumcontaining lanthanum tantalates (Li 3x La 2/3-x v 4/3-2x )Ta 2 O 6 have never been considered. This is the main purpose of (89 %) are obtained.…”