METHODS OF MAKING LITHIUM ION CONDUCTING SULFIDE GLASS
A lithium ion-conductive solid electrolyte including a freestanding inorganic vitreous sheet of sulfide-based lithium ion conducting glass is capable of high performance in a lithium metal battery. Such an electrolyte is also manufacturable, and readily adaptable for battery cell and cell component manufacture, in a cost-effective, scalable manner using an automated machine based system, apparatus and methods based on inline spectrophotometry to assess and inspect the quality of such vitreous solid electrolyte sheets and associated components. Suitable manufacturing methods can involve providing a sulfur precursor, providing a boron precursor material having lithium as a second constituent, combining the sulfur and boron precursor materials to form a precursor mixture, melting the mixture, and cooling the melt to form a solid lithium ion conducting glass. The glass may have a Li + conductivity of at least 10 −5 S/cm. The vessels in which the precursor materials are melted may include a secondary container or liner composed of a metal nitride or a metalloid nitride, such as boron nitride, silicon nitride, aluminum nitride, titanium nitride, zirconium nitride and hafnium nitride.
1 . A method of making a lithium ion conducting sulfide glass, the method comprising:
providing a primary vessel for melting glass;
providing a secondary container or liner, and positioning the secondary container or liner inside the primary vessel;
providing a precursor material mixture, the mixture comprising sulfur, lithium and at least one of boron or silicon.
disposing the precursor mixture into the secondary container or liner; and
heating the primary vessel to a temperature sufficient to form a melt of the precursor mixture;
wherein the melt does not contact the primary vessel and is chemically compatible in direct contact with the secondary container or liner.
2 . The method of claim 1 wherein the secondary container or liner is a metal or metalloid nitride.
3 . The method of claim 2 wherein the metal or metalloid nitride is selected from the group consisting of boron, titanium, silicon, zirconium, hafnium, and aluminum nitride.
4 . The method of claim 2 wherein the secondary container or liner is a metalloid nitride, and the metalloid nitride is boron nitride.
5 . The method of claim 2 wherein the secondary container or liner is a metal nitride, and the metal nitride is aluminum nitride.
6 . The method of claim 2 wherein the secondary container or liner is a metalloid nitride, and the metalloid nitride is silicon nitride.
7 . The method of claim 1 , wherein the providing, disposing and heating the precursor material mixture comprises:
i) providing a sulfur precursor material comprising sulfur as a main constituent element;
ii) providing a boron precursor material comprising boron as a first constituent element and lithium as a second constituent;
iii) combining the sulfur and boron precursor materials to form the precursor material mixture; and
iv) melting the mixture.
8 . The method of claim 7 , further comprising
v) cooling the melted mixture to form a solid lithium ion conducting glass having Li + conductivity greater than or equal to 10 −5 S/cm.