Systems and Methods of Making Solid-State Batteries and Associated Solid-State Battery Anodes

1 . A solid-state battery comprising:

a solid-state battery cathode;

a solid-state battery anode comprising:

a second solid electrolyte powder;

a plurality of graphite particles, wherein the plurality of graphite particles are characterized by a D50 diameter of less than 20 μm;

a solid-state interfacial coating comprising a low-crystallinity carbon, wherein the solid-state interfacial coating is coated onto the plurality of graphite particles; and

a plurality of conductive fibers, wherein the plurality of conductive fibers are interspersed between the plurality of graphite particles within the solid-state battery anode; and

a solid electrolyte separator positioned between the solid-state battery cathode and the solid-state battery anode to form the solid-state battery.

2 . The solid-state battery of claim 1 , wherein the solid-state battery cathode further comprises:

a first solid electrolyte powder; and

a plurality of cathode particles mixed with the first solid electrolyte powder to form the solid-state battery cathode.

3 . The solid-state battery of claim 1 , wherein the solid-state battery anode has a thickness from about 15 μm to about 100 μm.

4 . The solid-state battery of claim 1 , wherein the solid electrolyte separator has a thickness of from about 10 μm to about 100 μm.

5 . The solid-state battery of claim 1 , wherein the conductive fibers comprise vapor grown carbon fibers.

6 . A solid-state battery anode comprising:

a solid electrolyte powder;

a plurality of graphite particles mixed with the solid electrolyte powder to form a solid-state battery anode, wherein the plurality of graphite particles are characterized by a D50 diameter of less than 20 μm;

a solid-state interfacial coating comprising a low-crystallinity carbon, wherein the solid-state interfacial coating is coated on to the plurality of graphite particles to reduce interfacial reactivity between the plurality of graphite particles and the solid electrolyte powder within the solid-state battery anode; and

a plurality of conductive fibers, wherein the plurality of conductive fibers are interspersed between the plurality of graphite particles within the solid-state battery anode.

7 . The solid-state battery anode of claim 6 , wherein the solid-state battery anode comprises from about 50 wt. % to about 85 wt. % of the plurality of graphite particles.

8 . The solid-state battery anode of claim 6 , wherein the solid-state battery anode comprises from about 0 wt. % to about 5 wt. % of the plurality of conductive fibers.

9 . The solid-state battery anode of claim 6 , wherein the solid electrolyte powder consists of at least one of a polymer solid-state electrolyte, an inorganic solid-state electrolyte, or a sulfur based electrolyte.

10 . The solid-state battery anode of claim 6 , wherein the solid electrolyte powder comprises lithium phosphorus sulfide.

11 . The solid-state battery anode of claim 6 , wherein the solid-state battery anode comprises from about 10 wt. % to about 40 wt. % of the solid electrolyte powder.

12 . The solid-state battery anode of claim 6 , wherein the plurality of graphite particles comprises meso-carbon microbeads.

13 . The solid-state battery anode of claim 6 , wherein the plurality of graphite particles are characterized by a spherical shape.

14 . The solid-state battery anode of claim 6 , wherein the conductive fibers comprise carbon or graphite fibers.

15 . The solid-state battery anode of claim 14 , wherein at least 25%of the plurality of graphite particles are contacted by the conductive fibers.

16 . The solid-state battery anode of claim 6 , wherein the solid-state battery anode in a half-cell assembly has a discharge capacity greater than about 200 mAh/g.

17 . The solid-state battery anode of claim 6 , wherein the solid-state battery anode in a half-cell assembly has an initial coulombic efficiency greater than about 50%.

18 . A method of manufacturing a solid-state battery anode, the method comprising:

providing a graphite powder for a solid-state battery anode;

filtering the graphite powder to form a plurality of graphite particles characterized by a D50 diameter of less than 20 μm;

coating the plurality of graphite particles with a solid-state interfacial coating;

mixing a solid electrolyte powder with the plurality of graphite particles;

providing a plurality of conductive fibers;

mixing the conductive fibers with the solid electrolyte powder and the plurality of graphite particles to form a dry anode mixture; and

pressing the dry anode mixture to form the solid-state battery anode.

19 . The method of manufacturing the solid-state battery anode of claim 18 , wherein coating the plurality of graphite particles comprises spray coating the plurality of graphite particles with a low-crystallinity carbon in a fluidized bed.

20 . The method of manufacturing the solid-state battery anode of claim 18 , wherein mixing the solid electrolyte powder with the graphite particles comprises:

dissolving the solid electrolyte powder in a electrolyte solvent to form an electrolyte solution;

soaking the graphite particles in the electrolyte solution to form an anode solution; and

drying the anode solution.