Nanoscalar Silicon Particles In Negative Electrode Materials For Use In Lithium-Ion Batteries

• US 20070281216A1
• Filed: 03/17/2005
• Published: 12/06/2007
• Est. Priority Date: 04/01/2004
• Status: Active Grant

• Current Assignee: Nexeon Limited
• Original Assignee: Evonik Degussa GmbH
• Inventors: Petrat, Frank-Martin, Hennige, Volker, Albrecht, Evelyn, Buqa, Hilmi, Novak, Petr, Lee, David, Holzapfel, Michael
• Granted Patent: US 8,124,279 B2
• Time in Patent Office: Days
• US Class Current: 429/324
• CPC Class Codes: H01M 10/0525 Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
• CPC Class Codes: H01M 2004/021 Physical characteristics, e.g. porosity, surface area
• CPC Class Codes: H01M 4/133 Electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx
• CPC Class Codes: H01M 4/364 as mixtures
• CPC Class Codes: H01M 4/386 Silicon or alloys based on silicon
• CPC Class Codes: H01M 4/587 for inserting or intercalating light metals
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

The invention relates to an electrode material for a lithium ion battery which is distinguished by the fact that the electrode material comprises

• • 5-85% by weight of nanoscale silicon particles which have a BET surface area of from 5 to 700 m²/g and a mean primary particle diameter of from 5 to 200 nm, 0-10% by weight of conductive carbon black, 5-80% by weight of graphite having a mean particle diameter of from 1 μm to 100 μm and 5-25% by weight of a binder, the proportions of the components summing to not more than 100% by weight, and to the use of the electrode material according to the invention for the production of lithium ion batteries, and to a lithium ion battery having a negative electrode which comprises the electrode material according to the invention.

Claims

1. :

An electrode material for lithium ion batteries, characterized in that the electrode material comprises

5-85% by weight of nanoscale silicon particles which have a BET surface area of from 5 to 700 m²/g and a mean primary particle diameter of from 5 to 200 nm,

0-10% by weight of conductive carbon black,

5-80% by weight of graphite having a mean particle diameter of from 1 μ

m to 100 μ

m and

5-25% by weight of a binder,

the proportions of the components summing to not more than 100% by weight.

2. :

An electrode material according to claim 1, characterized in that the electrode material comprises

65-86.5% by weight of nanoscale silicon particles,

0.5-5% by weight of conductive carbon black,

8-20% by weight of graphite having a mean particle diameter of from 2 μ

m to 50 μ

m and

5-10% by weight of a binder.

3. :

An electrode material according to claim 1, characterized in that the electrode material comprises

5-40% by weight of nanoscale silicon particles,

55-85% by weight of graphite having a mean particle diameter of from 2 μ

m to 50 μ

m and

5-10% by weight of a binder.

4. :

An electrode material according to claim 1, characterized in that the nanoscale silicon particles are doped.

5. :

An electrode material according to claim 4, characterized in that the nanoscale silicon particles comprise not more than 53% by weight of lithium as a doping component.

6. :

An electrode material according to claim 1, characterized in that the nanoscale silicon particles have a BET surface area of from 6 to 140 m²/g.

7. :

The method of using an electrode material according to claim 1 for the production of lithium ion batteries.

8. :

The method of using according to claim 7, characterized in that an electrolyte composition which comprises from 0.5 to 10% by weight of vinylene carbonate is used as the electrolyte.

9. :

The method of using according to claim 7, characterized in that an electrolyte composition comprising at least one organic solvent and at least one alkali metal salt or alkaline earth metal salt is used as the electrolyte.

10. :

The method of using according to claim 9, characterized in that an electrolyte composition which comprises an organic solvent selected from ethylene carbonate, dimethyl carbonate, ethyl methyl carbonate, diethyl carbonate, propylene carbonate, butylene carbonate, methyl propyl carbonate, butyl methyl carbonate and its isomers, 1,2 dimethoxyethane, tetrahydrofuran, 2 methyltetrahydrofuran, diethylene glycol dialkyl ester, dioxolane, propylene oxide, dimethyl sulfoxide, dimethylformamide, formamide, nitromethane, gamma-butyrolactone, alkyl esters of carboxylic acids and/or methyl lactate is used as the electrolyte.

11. :

The method of using according to claim 9, characterized in that an electrolyte composition which comprises a conductive salt selected from LiPF₆, LiClO₄, LiAsF₆, LiBF₄, LiCF₃SO₃, LiN(CF₃SO₂)₂, LiN(SO₂CF₂CF₃)₂, LiSbF₆, LiAlCl₄, LiGaCl₄, LiCl, LiNO₃, LiSCN, LiO₃SCF₂CF₃, LiC₆F₅SO₃, LiO₂CCF₃, LiFSO₃, LiB(C₆H₅)₄, LiB(C₂O₄)₂, and/or lithium fluoroalkylphosphates is used as the electrolyte.

12. :

The method of using according to claim 7, characterized in that an electrolyte composition in which the concentration of the conductive salt is from 0.5 mol/l to the solubility limit of the corresponding salt is used as the electrolyte.

13. :

A lithium ion battery having a negative electrode which comprises an electrode material according to claim 1.