Structured silicon anode

• US 8,384,058 B2
• Filed: 08/05/2011
• Issued: 02/26/2013
• Est. Priority Date: 11/05/2002
• Status: Expired due to Term

• Current Assignee: Nexeon Limited
• Original Assignee: Nexeon Limited
• Inventors: Green, Mino
• Primary Examiner(s): Valentine, Jami M
• Application Number:
  US13/204,229
• Publication Number:
  US 20120003536A1
• Time in Patent Office: 571 Days
• Field of Search: 257 1- 5, 257/119, 438/95, 438/800, 438/900, 320/107, 429/52, 977/948, 977/701, 977/810, 977/932
• US Class Current: 257/2
• CPC Class Codes: H01M 10/052 Li-accumulators
• CPC Class Codes: H01M 2004/027 Negative electrodes
• CPC Class Codes: H01M 4/04 Processes of manufacture in general
• CPC Class Codes: H01M 4/134 Electrodes based on metals, Si or alloys
• CPC Class Codes: H01M 4/1395 of electrodes based on metals, Si or alloys
• CPC Class Codes: H01M 4/386 Silicon or alloys based on silicon
• CPC Class Codes: H01M 4/661 Metal or alloys, e.g. alloy coatings H01M4/669 take precedence
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y10S 438/90 Bulk effect device making
• CPC Class Codes: Y10S 977/701 Integrated with dissimilar structures on a common substrate
• CPC Class Codes: Y10S 977/81 Of specified metal or metal alloy composition
• CPC Class Codes: Y10S 977/932 for electronic or optoelectronic application
• CPC Class Codes: Y10S 977/948 Energy storage/generating using nanostructure, e.g. fuel cell, battery
• CPC Class Codes: Y10T 29/49108 Electric battery cell making

Abstract

A battery can be fabricated from a substrate including silicon. This allows the battery to be produced as an integrated unit. The battery includes a anode formed from an array of spaced elongated structures, such as pillars, which include silicon and which can be fabricated on the substrate. The battery also includes a cathode which can include lithium.

Claims

1. An electrode for a battery comprising a plurality of silicon-comprising elongated structures extending from a substrate and arranged to engage with a lithium-based cathode and a lithium-based electrolyte, wherein the elongated structures have a length greater than 1 micron.

2. An electrode as claimed in claim 1 wherein the elongated structures have a gravimetric capacity of at least 780 mAh/g for the first 10 cycles.

3. An electrode as claimed in claim 1 wherein the elongated structures have a gravimetric capacity of at least 620 mAh/g for the first 50 cycles.

4. An electrode as claimed in claim 1 wherein the elongated structures have a volumetric capacity of at least 1800 mAh/cm³ for the first 10 cycles.

5. An electrode as claimed in claim 1 wherein the elongated structures have a volumetric capacity of at least 1450 mAh/cm³ for the first 50 cycles.

6. An electrode as claimed in claim 1 wherein the electrode is arranged to tolerate the conditions occasioned by the volume changes caused by charging/discharging.

7. An electrode as claimed in claim 1 wherein the elongated structures do not exceed a fractional coverage of 0.5 of the substrate.

8. An electrode as claimed in claim 1 wherein the elongated structures have a diameter of up 1.0 micron.

21. An electrode as claimed in claim 1 further comprising a lithium-containing electrolyte which comprises at least one of a lithium salt in a solvent or a polymer electrolyte.

9. A lithium-ion battery electrode comprising:

a plurality of spaced elongated structures each attached at one end to a substrate and extending away therefrom,

wherein the elongated structures comprise silicon.

10. A lithium-ion battery electrode as claimed in claim 9 wherein the elongated structures have a gravimetric capacity of at least 620 mAh/g for the first 50 cycles.

11. A lithium-ion battery electrode as claimed in claim 9 wherein the elongated structures have a volumetric capacity of at least 1450 mAh/cm³ for the first 50 cycles.

15. An electrode as claimed in claim 9 wherein the electrode is arranged to tolerate the conditions occasioned by the volume changes caused by charging/discharging.

16. An electrode as claimed in claim 9 wherein the elongated structures do not exceed a fractional coverage of 0.5 of the substrate.

17. An electrode as claimed in claim 9 wherein the elongated structures have a diameter of up to 1.0 micron.

18. An electrode as claimed in claim 9 wherein the elongated structures have a length greater than 1 micron.

19. An electrode as claimed in claim 9 wherein the elongated structures have an aspect ratio (length to diameter ratio) in the range 1 to 100.

12. An energy storage device comprising:

a plurality of silicon-comprising elongated structures extending from a substrate; and

a cathode, wherein the elongated structures are arranged to tolerate the conditions occasioned by the volume charges caused by charging/discharging with lithium, wherein the elongated structures do not exceed a fractional coverage of 0.5 of the substrate.

13. An energy storage device as claimed in claim 12 wherein the elongated structures have a gravimetric capacity of at least 620 mAh/g for the first 50 cycles.

14. An energy storage device as claimed in claim 12 further comprising a lithium-containing electrolyte which comprises at least one of a lithium salt in a solvent or a polymer electrolyte.

20. An electrode as claimed in claim 12 wherein the elongated structures have a diameter of up to 1.0 micron.