Negative electrode material for lithium-based batteries

Patent metadata

Field	Value
Publication number	US-9570752-B2
Application number	US-201414280257-A
Country	US
Kind code	B2
Filing date	May 16, 2014
Priority date	May 16, 2014
Publication date	Feb 14, 2017
Grant date	Feb 14, 2017

Abstract

A negative electrode material includes an active material, which is present in an amount ranging from about 60 wt % to about 95 wt % of a total wt % of the negative electrode material. The negative electrode material further includes a polyimide binder, which is present in an amount ranging from about 1 wt % to about 20 wt % of the total wt % of the negative electrode material. The polyimide binder contains a repeating unit, where a backbone structure of each repeating unit has no ether group present and no more than one carbonyl group present. The negative electrode material also includes a conductive filler, which is present in an amount ranging from about 3 wt % to about 20 wt % of the total wt % of the negative electrode material.

First claim

What is claimed is:

1. A negative electrode material, comprising:
an active material present in an amount ranging from about 60 wt % to about 95 wt % of a total wt % of the negative electrode material, wherein the active material includes carbon coated silicon, carbon coated silicon alloy, or a combination thereof, and wherein the active material has a diameter ranging from about 30 nm to less than 1000 nm;
a polyimide binder present in an amount ranging from about 1 wt % to about 20 wt % of the total wt % of the negative electrode material, wherein a backbone structure of each repeating unit of the polyimide binder has no ether group present and no more than one carbonyl group present; and
a conductive filler present in an amount ranging from about 3 wt % to about 20 wt % of the total wt % of the negative electrode material.

2. The negative electrode material as defined in claim 1 wherein the active material further includes silicon.

3. The negative electrode material as defined in claim 1 , further comprising an other active material present in an amount ranging from about 1 wt % to about 20 wt % of the total wt % of the negative electrode material, wherein the other active material is graphite.

4. The negative electrode material as defined in claim 1 wherein:
the polyimide binder is formed from a diamide monomer and a dianhydride monomer;
the diamide monomer is selected from the group consisting of p-phenylenediamine, toluene diamine, and diaminodiphenylmethane; and
the dianhydride is selected from the group consisting of 3,3′,4,4′-biphenyltetracarboxylic dianhydride, 4,4′,5,5′-sulfonyldiphthalic anhydride, 3,3′,4,4′-benzophenonetetracarboxylic dianyhdride, and pyromellitic dianhydride.

5. The negative electrode material as defined in claim 1 wherein the conductive filler is selected from the group consisting of carbon black, carbon nanofibers, or a combination thereof.

6. The negative electrode material as defined in claim 5 wherein:
the conductive filler consists of a combination of the carbon black and the carbon nanofibers; and
the carbon black and the carbon nanofibers are present in a ratio ranging from about 1:1 to about 1:3.

7. The negative electrode material as defined in claim 1 wherein the backbone structure of each repeating unit of the polyimide binder has no ether group and no carbonyl group present.

8. The negative electrode material as defined in claim 1 wherein the polyimide binder has a molecular weight ranging from about 75,000 grams/mole to about 750,000 grams/mole.

9. The negative electrode material as defined in claim 1 wherein the active material consists of carbon coated silicon.

10. A negative electrode material, consisting of:
an active material present in an amount ranging from about 60 wt % to about 95 wt % of a total wt % of the negative electrode material, wherein the active material is selected from the group consisting of carbon coated silicon, carbon coated silicon alloy, and combinations thereof, and wherein the active material has a diameter ranging from about 30 nm to less than 1000 nm;
a polyimide binder present in an amount ranging from about 1 wt % to about 20 wt % of the total wt % of the negative electrode material, wherein a backbone structure of each repeating unit of the polyimide binder has no ether group present and no more than one carbonyl group present; and
a conductive filler present in an amount ranging from about 1 wt % to about 20 wt % of the total wt % of the negative electrode material.

11. A lithium-based battery, comprising:
a positive electrode;
a negative electrode including:
an active material present in an amount ranging from about 60 wt % to about 95 wt % of the total wt % of the negative electrode material, wherein the active material includes carbon coated silicon, carbon coated silicon alloy, or a combination thereof, and wherein the active material has a diameter ranging from about 30 nm to less than 1000 nm;
a polyimide binder present in an amount ranging from about 1 wt % to about 20 wt % of the total wt % of the negative electrode material, wherein a backbone structure of each repeating unit of the polyimide binder has no ether group present and no more than one carbonyl group present;
a conductive filler present in an amount ranging from about 1 wt % to about 20 wt % of the total wt % of the negative electrode material; and

a microporous polymer separator soaked in an electrolyte solution, the microporous polymer separator being disposed between the positive electrode and the negative electrode.

12. The lithium-based battery as defined in claim 11 wherein:
the lithium-based battery is a lithium ion battery:
the positive electrode includes a lithium transition metal oxide based active material selected from the group consisting of LiMn 2 O 4 , Li(Ni 0.5 Mn 1.5 )O 2 , Li(Ni x Mn y Co z )O 4 , LiCoO 2 , LiNiO 2 , LiFePO 4 , Li 2 MSiO 4 (M =Co, Fe, Mn), xLi 2 MnO 3 -(1−x)LiMO 2 (M is composed of any ratio of Ni, Mn and Co), and a high efficiency nickel-manganese-cobalt material; and
the electrolyte solution includes an organic solvent and a lithium salt dissolved in the organic solvent, the organic solvent being selected from the group consisting of cyclic carbonates, linear carbonates, aliphatic carboxylic esters, γ-lactones, chain structure ethers, cyclic ethers, and mixtures thereof, and the lithium salt being selected from the group consisting of LiClO 4 , LiAlCl 4 , LiI, LiBr, LiSCN, LiBF 4 , LiB(C 6 H 5 ) 4 LiAsF 6 , LiCF 3 SO 3 , LiN(FSO 2 ) 2 , LiN(CF 3 SO 2 ) 2 , LiAsF 6 , LiPF 6 , LITFSI, and mixtures thereof.

13. The lithium-based battery as defined in claim 11 wherein:
the lithium-based battery is a lithium-sulfur battery:
the positive electrode includes a sulfur based active material selected from the group consisting of S 8 , Li 2 S 8 , Li 2 S 6 , Li 2 S 4 , Li 2 S 2 , and Li 2 S; and
the electrolyte solution includes an ether based solvent and a lithium salt dissolved in the ether based solvent, the ether based solvent being selected from the group consisting of 1,3-dioxolane, tetrahydrofuran, 2 -methyltetrahydrofuran, 1,2-dimethoxyethane, 1-2-diethoxyethane, ethoxymethoxyethane, tetraethylene glycol dimethyl ether (TEGDME), polyethylene glycol dimethyl ether (PEGDME), and mixtures thereof, and the lithium salt being selected from the group consisting of LiClO 4 , LiAlCl 4 , LiI, LiBr, LiSCN, LiBF 4 , LiB(C 6 H 5 ) 4 LiAsF 6 , LiCF 3 SO 3 , LiN(FSO 2 ) 2 , LiN(CF 3 SO 2 ) 2 , LiAsF 6 , LiPF 6 , LITFSI, and mixtures thereof.

14. The lithium-based battery as defined in claim 11 wherein:
the active material further includes silicon; and
the negative electrode further includes an other active material present in an amount ranging from about 1 wt % to about 20 wt % of the total wt % of the negative electrode material, wherein the other active material is graphite.

15. The lithium-based battery as defined in claim 11 wherein:
the polyimide binder is formed from a diamide monomer and a dianhydride monomer;
the diamide monomer is selected from the group consisting of p-phenylenediamine, toluene diamine, and diaminodiphenylmethane; and
the dianhydride is selected from the group consisting of 3,3′,4,4′-biphenyltetracarboxylic dianhydride, 4,4′,5,5′-sulfonyldiphthalic anhydride, 3,3′,4,4′-benzophenonetetracarboxylic dianyhdride, and pyromellitic dianhydride.

16. The lithium-based battery as defined in claim 11 wherein:
the conductive filler consists of a combination of carbon black and carbon nanofibers; and
the carbon black and the carbon nanofibers are present in a ratio

Assignees

• Gm Global Tech Operations Llc

Inventors

• Huang Xiaosong
• Cai Mei

Classifications

• H01M4/0404

  by coating on electrode collectors · CPC title

• H01M4/622 Primary

  being polymers · CPC title

• H01M4/364

  as mixtures · CPC title

• H01M4/5825

  Oxygenated metallic salts or polyanionic structures, e.g. borates, phosphates, silicates, olivines · CPC title

• H01M4/386

  Silicon or alloys based on silicon · CPC title