Solid-state laminate electrode assemblies and methods of making
Solid-state laminate electrode assemblies and various methods for making the solid-state laminate electrode assemblies involve a lithium metal layer reactively bonded to a lithium ion conducting sulfide glass layer. During manufacture, highly reactive surfaces of the lithium metal layer and the lithium ion conducting sulfide glass layer are maintained in its substantially unpassivated state until they have been reactively bonded.
1. A method for making a battery cell, the method comprising making a solid-state electrode assembly comprising the steps of
i) providing a lithium metal laminate structure, the lithium metal laminate structure comprising:
a. a lithium metal layer having a first major surface that is substantially unpassivated; and
b. a first fluid inert protective material layer that removably covers the lithium metal layer first major surface, the first inert protective material layer in direct contact with the lithium metal layer first major surface;
ii) providing an inorganic solid electrolyte laminate structure, the electrolyte laminate structure comprising:
a. an inorganic lithium ion conducting sulfide glass layer having a first major surface and an opposing second major surface; and
b. a second fluid inert protective material layer that removably covers the sulfide glass layer first major surface, the second inert protective material layer in direct contact with the sulfide glass layer;
iii) removing the first inert protective material layer from the lithium metal layer first major surface;
iv) removing the second inert protective material layer from the sulfide glass layer first major surface;
v) reactively bonding the sulfide glass layer with the lithium metal layer via their first major surfaces; and
wherein the reactive bond provides an interface between the sulfide glass layer and the lithium metal layer defined by a continuous solid electrolyte interphase; and
placing a positive electrode layer adjacent to the second major surface of the sulfide glass layer.
2. The method of claim 1 , wherein the second fluid inert protective material layer on the sulfide glass layer first major surface is a layer of a second dry hydrocarbon liquid, and the first fluid inert protective material layer on the substantially unpassivated lithium metal layer first major surface is a layer of a first dry hydrocarbon liquid.
3. The method of claim 2 , wherein the first dry hydrocarbon liquid on the lithium metal layer surface is removed substantially immediately prior to the reactive bonding.
4. The method of claim 3 , wherein the removal of the first hydrocarbon liquid is accelerated by the application of one or more of heat, vacuum suction, blowing a jet of dry Ar or He, and blowing a jet of high vapor pressure protective liquid followed by vacuum suction.
5. The method of claim 4 , further comprising cleaning the first major surface of the sulfide glass layer by ion etching under an argon plasma, wherein the cleaning is performed after the liquid phase layer of the second dry hydrocarbon liquid has been removed.
6. The method of claim 3 , wherein the first liquid phase protective fluid is a hydrocarbon liquid comprising not greater than 0.1 ppm of moisture.
7. The method of claim 3 , wherein the second dry hydrocarbon liquid on the sulfide glass layer is removed substantially immediately prior to the reactive bonding.
8. The method of claim 7 , wherein the second liquid phase protective fluid is a hydrocarbon liquid comprising not greater than 0.1 ppm of moisture.