Sulfide solid electrolyte for solid-state batteries and method for production

Abstract

A solid electrolyte for solid-state batteries comprises a phosphorous-free solid electrolyte having a cubic argyrodite structure. The solid electrolyte has a composition according to the molecular formula: Li.sub.6+xM.sub.xSb.sub.1yS.sub.5zR, where x=0 to 0.7; y=0 to 0.7 and z=0 to 0.7, wherein the (semi-) metal comprises M=Si, Sn, W and the halogen comprises R=I.sub.1, Cl.sub.1, Br.sub.z, Br.sub.1 and further wherein, in a case where R=I.sub.1, M=W and x>0. Furthermore, a production method is described.

Claims

1. A sulfide solid electrolyte for solid-state batteries, the sulfide solid electrolyte comprising: a phosphorous-free solid electrolyte having a cubic argyrodite structure and a composition according to the molecular formula Li.sub.6+x M.sub.x Sb.sub.1y S.sub.5z R, wherein 0<x0.7, y=0 to 0.7 and z=0 to 0.7, wherein M is selected from the group consisting of Si and Sn, and wherein R is selected from the group consisting of Cl.sub.1 and Br.sub.1.

2. The sulfide solid electrolyte according to claim 1, wherein z=0 and x=y, where 0<x0.6.

3. A method for producing a solid electrolyte according to claim 1, the method comprising: mixing the reactants: Li.sub.2S, and SbS.sub.3 or Sb.sub.2S.sub.5, and SiS.sub.2 and/or SnS.sub.2, and LiCl and/or LiBr into a vitreous amorphous powder mixture; heating the amorphous powder mixture to a temperature between 470 C.-580 C. in an argon atmosphere, or heating the amorphous powder mixture in a static or dynamic vacuum at a temperature between 400-600 C., each for 1-7 days, thereby producing the phosphorous-free solid electrolyte.

4. The method according to claim 3, wherein the Li.sub.2S used in the powder mixture has a particle size of less than 3 m.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIGS. 1A-1D show tabular lists of different compositions.

DETAILED DESCRIPTION OF THE DRAWINGS

(2) In the representation of FIGS. 1A-1D, possible compositions of the solid electrolyte for solid-state batteries are represented in four individual tables. The compositions in the tables describe the material available in the first left-hand column, using the formula and the factors x, y, z. In the following column, different values for the factor x are specified, which is the same as the factor y or z for each composition. The further columns show the raw materials from which the material is produced. Therefore, the antimony sulfide here may be listed as an antimony(V) sulfide, but antimony(III) sulfide may also be used; the ratios given below would then have to be adjusted accordingly. The reactant for the (semi-)metal M is silicon sulfide in the tables shown in FIGS. 1A and 1B and tungsten sulfide in the table shown in FIG. 1C. In the table shown in FIG. 1D, no (semi-)metal is required. In the right-hand column, in the three tables of FIGS. 1A-1C, and in the two right-hand columns of the table in FIG. 1D, the respective required lithium halide is provided. The quantities for the individual reactants are to be understood in moles.

(3) For example, a solid electrolyte with the molecular formula Li.sub.6,6Sb.sub.0,4Si.sub.0,6S.sub.5Cl.sub.1 according to the last line of the table in FIG. 1A requires 1.434 Mol Li.sub.2S; 0.642 Mol Sb.sub.2S.sub.3; 0.523 Mol SiS.sub.2 and 0.401 Mol LiCl. These starting quantities, which can be adjusted, i.e. increased or decreased in a suitable ratio as required, are mixed together. The mixture of amorphous vitreous powder is then heated, e.g. at 470 C. to 580 C. in an argon atmosphere for 1 to 7 days, in order to obtain the crystalline structure of the solid electrolyte.

(4) For the other compositions, this would occur analogously.