Lithium ion rechargeable battery
Embodiments of the disclosed lithium ion rechargeable battery include an anode, a cathode, and a separator including an electrolyte to prevent physical contact between the anode and the cathode, while also providing medium for transporting the lithium ions. In some embodiments, the anode may include a microporous scaffold structure that includes a silicon crystal covered in a thin polycrystalline silicon cover. Additionally, the various embodiments described herein further describe increasing the surface area of the microporous scaffold structure so as to provide a more efficient charge flow between the anode and the cathode. In some embodiment, the two or more microporous scaffold structures are stacked on top of one another so that there is an increase in contact area and reduced contact resistance, thus further increasing the charge capacity of the disclosed lithium ion rechargeable battery.
1. A rechargeable battery comprising:
an anode;
a cathode; and
a separator comprising an electrolyte to prevent physical contact between the anode and the cathode while also providing a medium for transporting ions;
wherein the anode comprises:
a microporous scaffold structure comprising a silicon crystal covered in a polycrystalline silicon layer; and
a protective layer deposited over the microporous scaffold structure to prevent a lithium ion from penetrating into the microporous scaffold structure, wherein the thin polycrystalline silicon layer is deposited over the protective layer.
2. The rechargeable battery of claim 1 , wherein the protective layer comprises a noble metal to collect a current.
3. The rechargeable battery of claim 2 , wherein the protective layer comprises a material made of platinum or gold.
4. The rechargeable battery of claim 1 , wherein the protective layer comprises a material made of titanium nitride or tantalum nitride.
5. The rechargeable battery of claim 1 , wherein the anode further comprises at least two or more microporous scaffold structures that are stacked on top of one another, such that there is an increase in contact area between the two or more microporous scaffold structures to reduce contact resistance of the rechargeable battery.
6. The rechargeable battery of claim 5 , wherein the two or more microporous scaffold structures are stacked, such that a bottom layer with respect to a top layer is angled at 30°-60°.
7. The rechargeable battery of claim 1 , wherein the microporous scaffold structure comprises periodic channels, such that each periodic channel comprises a surrounding wall and a hollow center.
8. The rechargeable battery of claim 1 , wherein the microporous scaffold structure comprises individual wafer chips in a shape of an equilateral polygon cut from a silicon wafer.
9. The rechargeable battery of claim 8 , wherein the shape of the equilateral polygon is a hexagon.
10. The rechargeable battery of claim 8 , wherein the wafer chips comprise a material made of silicon crystal.
11. The rechargeable battery of claim 9 , wherein the wafer chips of the microporous scaffold structure have no solid border along a perimeter of the wafer chips, thus allowing the wafer chips to expand laterally during a charge and a discharge cycle of the rechargeable battery.
12. A method for producing a rechargeable battery comprising:
providing a battery comprising:
an anode comprising a microporous scaffold structure made of silicon crystal with a polycrystalline silicon layer;
a cathode;
a permeable barrier comprising an electrolyte in between the anode and the cathode;
forming hollow periodic channels in the microporous scaffold structure of the anode; and
depositing the microporous scaffold structure of the anode with a protective layer comprising platinum, gold, or titanium nitride to prevent a lithium ion from penetrating into the microporous scaffold structure.
13. The method of claim 12 , further comprising stacking at least a top microporous scaffold structure over a bottom microporous structure to create a stacked anode structure.
14. The method of claim 13 , further comprising rotating the top microporous structure with respect to the bottom microporous structure, so as to provide increased contact area between the stacked anode structures.
15. The method of claim 14 , wherein rotating the top microporous structure with respect to the bottom microporous structure ranges from a 30°-60° shift.
16. The method of claim 13 , wherein the stacked anode structures are shifted laterally with respect to the top microporous structure and the bottom microporous structure.
17. The method of claim 12 , wherein the microporous scaffold structure comprises individual silicon chips cut in a shape of a hexagon from a silicon wafer.
18. The method of claim 17 , wherein the silicon chips of the microporous scaffold structure have no solid boundary at an outermost perimeter, thus allowing the microporous scaffold structure to expand laterally with an intercalation of a lithium ion during a charge and a discharge cycle of the rechargeable battery.