Energy storage device containing a pre-lithiated silicon based anode and a carbon nanotube based cathode

Patent metadata

Field	Value
Publication number	US-11437614-B2
Application number	US-201916707739-A
Country	US
Kind code	B2
Filing date	Dec 9, 2019
Priority date	Dec 9, 2019
Publication date	Sep 6, 2022
Grant date	Sep 6, 2022

Abstract

An energy storage device is provided that includes a pre-lithiated silicon based anode and a carbon nanotube based cathode. The pre-lithiated silicon anode has a porous region and a non-porous region. The full cell energy storage device has high electrochemical performance which exhibits greater 200 rechargeable cycles with less than 25% after 10 charge discharge cycles relative to the first discharge cycle, a maximum specific discharge capacity greater than 300 mAh/g and a specific capacity of greater than 100 mAh/g for over 130 cycles. Such an energy storage device is scalable for a wide array of applications due to its wafer level processing and silicon-based substrate integrability.

First claim

What is claimed is:

1. An energy storage device comprising:
a silicon based anode containing a porous region and a non-porous region, wherein the porous region comprises a top porous layer having a first thickness and a first porosity, and a bottom porous layer having a second thickness that is greater than the first thickness, and a second porosity that is greater than the first porosity, and wherein the bottom porous layer forms an interface with the non-porous region;
a lithium metal layer located on, and absorbed at least partially into, a topmost surface of the porous region of the silicon based anode;
a liquid electrolyte having a first surface forming an interface with the lithium metal layer;
a carbon nanotube based cathode forming an interface with a second surface of the liquid electrolyte, which is opposite the first surface of the liquid electrolyte; and
an ionic-permeable and electron-insulating separator positioned between the silicon based anode and the carbon nanotube based cathode and configured to separate the liquid electrolyte into a first electrolyte region having the first surface and a second electrolyte region having the second surface.

2. The energy storage device of claim 1 , wherein the porous region and the non-porous region of the silicon based anode are both composed of crystalline silicon.

3. The energy storage device of claim 1 , wherein the silicon based anode including the porous region and the non-porous region is entirely composed of a p-type doped silicon having a p-type dopant concentration of about 10 19 cm −3 .

4. The energy storage device of claim 1 , wherein the lithium metal layer is present in an entirety of the porous region of the silicon based anode.

5. The energy storage device of claim 1 , wherein the lithium metal layer that is located on the topmost surface of the porous region of the silicon based anode has a thickness of 15 nm to 100 nm.

6. The energy storage device of claim 1 , wherein the carbon nanotube based cathode is composed of a carbon nanotube active material, a binding agent and a conductive lithium containing salt.

7. The energy storage device of claim 6 , wherein the binding agent is polyvinylidene fluoride, and the conductive lithium containing salt is lithium bis(trifluoromethanesulfonyl)imide.

8. The energy storage device of claim 6 , wherein the carbon nanotube active material comprises doped carbon nanotubes.

9. The energy storage device of claim 6 , wherein the carbon nanotube active material comprises non-doped carbon nanotubes or a combination of doped carbon nanotubes and non-doped carbon nanotubes.

10. The energy storage device of claim 1 , wherein the liquid electrolyte comprises a solvent mixture of ethylene carbonate and dimethyl carbonate, a lithium salt comprising lithium hexafluorophosphate, and an additive comprising fluoroethylene carbonate.

11. An energy storage device comprising:
a crystalline silicon based anode containing a porous region and a non-porous region, wherein the porous region comprises a top porous layer having a first thickness and a first porosity, and a bottom porous layer having a second thickness that is greater than the first thickness, and a second porosity that is greater than the first porosity, and wherein the bottom porous layer forms an interface with the non-porous region;
a lithium metal layer located on, and absorbed at least partially into, the top porous layer of the crystalline silicon based anode;
a liquid electrolyte having a first surface forming an interface with the lithium metal layer, wherein the liquid electrolyte comprises a mixture of ethylene carbonate, dimethyl carbonate, lithium hexafluorophosphate, and fluoroethylene carbonate;
a carbon nanotube based cathode forming an interface with a second surface of the liquid electrolyte, which is opposite the first surface of the liquid electrolyte, wherein the carbon nanotube based cathode is composed of a carbon nanotube active material, polyvinylidene fluoride as a binding agent, and lithium bis(trifluoromethanesulfonyl)imide as a conductive lithium containing salt; and
an ionic-permeable and electron-insulating separator located in the liquid electrolyte and between the silicon based anode and the carbon nanotube based cathode.

Assignees

• IBM

Inventors

• Collins John
• Afzali-Ardakani Ali
• De Souza Joel P
• Sadana Devendra K

Classifications

• H01M4/366 Primary

  as layered products · CPC title

• H01M2300/0025

  Organic electrolyte · CPC title

• H01M2004/021

  Physical characteristics, e.g. porosity, surface area · CPC title

• H01M10/0568

  characterised by the solutes · CPC title

• H01M2300/0028

  characterised by the solvent · CPC title