Sulfidic solid electroylyte and its precursor II
The present invention relates to a solid electrolyte, its precursor, methods for producing the same as well as its use, e.g. in electrochemical cells and capacitors, fuel cells, batteries and sensors.
1 . A solid electrolyte precursor represented by the following formula (I):
Li (2a−n) Y n+ S a (I)
wherein Y is independently selected from P, As, B, Si, Al, Ga, and Sb,
4≤n≤5, and
3.8≤a≤5.2;
wherein the precursor comprises (a) no dopants, (b) one dopant selected from the group consisting of Mn, Ge, Sn, V, Ni, Cr, Si, Al, As, O, Sb, B, Ga, Se, Te, Mg, Na, and Ca in its oxidation state, or (c) a mixture of two or more dopants selected from the group consisting of Mn, Ge, Sn, V, Ni, Cr, Si, Al, As, O, Sb, B, Ga, Se, Te, Mg, Na, and Ca in their respective oxidation state.
2 . A method for producing a solid electrolyte precursor according to claim 1 , comprising the steps of:
(i) providing a lithium salt in a reaction vessel,
(ii) contacting a sulfur-containing reaction gas with the lithium salt of step (i) at elevated temperatures,
(iii) contacting a Y-containing component with the product obtained in step (ii) at elevated temperatures, and
(iv) optionally discharging the product obtained in step (iii),
wherein the Y-containing component is at least partially present in a gaseous phase.
3 . The method according to claim 2 , wherein in step (ii) the molar ratio of S in sulfur-containing reaction gas to Li in lithium salt provided in step (i) is 1:1-1:10.
4 . The method according to claim 2 , wherein in step (iii) the molar ratio of Y in Y-containing component to Li in lithium salt provided in step (i) is 1:1-1:10.
5 . The method according to claim 2 , wherein step (ii) and/or step (iii) is performed at a total gas flow of 0.1-1000 m 3 /h.
6 . A method for preparing a solid electrolyte using a solid electrolyte precursor according to claim 1 , wherein the solid electrolyte is represented by the following formula (II):
Li (2b+c−m) Y m+ S b X c (II)
wherein X is independently selected from group 17 elements,
Y is independently selected from P, As, B, Al, Ga, and Sb,
4≤m≤5,
3.8≤b≤5.2, and
0≤c≤2.
7 . A method for preparing a solid electrolyte, comprising the steps of:
(a) providing a solid electrolyte precursor according to claim 1 , in a reaction vessel,
(b) contacting at least one X-containing and/or S-containing lithium salt and/or Y-containing sulfide with the solid electrolyte precursor of step (a) at elevated temperatures, and
(c) optionally discharging the product obtained in step (b).
8 . The method according to claim 7 , wherein the X-containing lithium salt is a halide.
9 . The method according to claim 7 , wherein in step (b) the molar ratio of X in X-containing lithium salt or of S in the S-containing lithium salt to solid electrolyte precursor provided in step (a) is 0.01:1-3:1.
10 . The method according to claim 7 , further comprising a step (b.1) of adding to the product obtained in step (b) at least one doping agent.
11 . A solid electrolyte obtainable by a method according to claim 7 .
12 . An electrochemical cell comprising the solid electrolyte according to claim 11 .
13 . The precursor according to claim 1 , wherein the precursor is selected from Li 5 PS 5 , Li 5 AsS 5 , Li 5 SbS 5 or mixtures thereof.
14 . The precursor according to claim 13 , wherein the mixtures are physical mixtures, mixed crystals, and/or solid solutions.
15 . The method of claim 2 , wherein the lithium salt is LiOH, Li 2 CO 3 , Li 2 SO 4 , Li 2 O, Li 2 O 2 or a mixture thereof.
16 . The method of claim 2 , wherein the sulfur-containing reaction gas is H 2 S, S 8 , CS 2 , mercaptanes or a mixture thereof.
17 . The method according to claim 2 , wherein the Y-containing component is P 2 S 5 , As 2 S 5 , B 2 S 3 , Ga 2 S 3 , Al 2 S 3 , Sb 2 S 5 or a mixture thereof.