Negative electrode material for lithium-based batteries
A negative electrode material includes an active material. The active material includes a silicon core selected from the group consisting of Si, SiO 2 , SiO x (0<x<2), a silicon alloy, and a combination thereof. The active material also includes a hard carbon coating formed on the silicon core. The negative electrode material further includes a non-fluorinated binder. The negative electrode material also includes a conductive filler. The loading of the active material in the negative electrode material is greater than 2 mg/cm 2 .
1. A negative electrode material, comprising:
an active material, including:
a silicon core selected from the group consisting of Si, SiO 2 , SiO x (0<x<2), a silicon alloy, and a combination thereof; and
a hard carbon coating formed on the silicon core;
a non-fluorinated binder selected from the group consisting of sodium alginate and polyacrylic acid, wherein at least some of the non-fluorinated binder is chemically bound to the hard carbon coating; and
a conductive filler;
wherein a loading of the active material in the negative electrode material is greater than 2 mg/cm 2 .
2. The negative electrode material as defined in claim 1 , wherein the silicon core has a diameter ranging from about 10 nm to about 20 nm, and the hard carbon coating has a thickness ranging from about 2 nm to about 20 nm.
3. The negative electrode material as defined in claim 1 , wherein the negative electrode material has a porosity ranging from about 30% to about 80%.
4. The negative electrode material as defined in claim 1 , wherein the negative electrode material is pre-lithiated with a lithium metal, or a lithium salt selected from the group consisting of LiPF 6 , LiBF 4 , LiClO 4 , LiN(SO 2 CF 3 ) 2 (LiTFSI), LiB(C 2 O 4 ) 2 (LiBOB), LiBF 2 (C 2 O 4 ) (LiODFB), LiPF 4 (C 2 O 4 ) (LiFOP), LiNO 3 , LiN(SO 2 F) 2 (LiFSI), LiPF 3 (C 2 F 5 ) 3 (LiFAP), LiPF 4 (CF 3 ) 2 , LiPF 3 (CF 3 ) 3 , and a combination thereof.
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, graphene, graphite, and a combination thereof.
6. The negative electrode material as defined in claim 1 , excluding any other binder material.
7. The negative electrode material as defined in claim 1 , wherein:
the active material is present in an amount ranging from about 30 wt % to about 95 wt % of a total wt % of the negative electrode material;
the non-fluorinated binder is present in an amount ranging from about 0.1 wt % to about 20 wt % of the total wt % of the negative electrode material; and
the conductive filler is present in an amount ranging from about 0.1 wt % to about 50 wt % of the total wt % of the negative electrode material.
8. A lithium-based battery, comprising:
a positive electrode;
a negative electrode including:
an active material, including:
a silicon core selected from the group consisting of Si, SiO 2 , SiO x (0<x<2), a silicon alloy, and a combination thereof; and
a hard carbon coating formed on the silicon core;
a non-fluorinated binder selected from the group consisting of sodium alginate and polyacrylic acid, wherein at least some of the non-fluorinated binder is chemically bound to the hard carbon coating; and
a conductive filler;
wherein a loading of the active material in the negative electrode is greater than 2 mg/cm 2 ; and
a microporous polymer separator soaked in an electrolyte solution, the microporous polymer separator being disposed between the positive electrode and the negative electrode.
9. The lithium-based battery as defined in claim 8 , 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 , LiNi x M 1-x O 2 (M is composed of any ratio of Al, Co, and Mg), 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 , LiPF 6 , LITFSI, LiPF 4 (C 2 O 4 ) (LiFOP), LiNO 3 , and mixtures thereof.
10. The lithium-based battery as defined in claim 8 ,
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, LiB(C 2 O 4 ) 2 (LiBOB), LiBF 2 (C 2 O 4 ) (LiODFB), 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 , LiPF 6 , LITFSI, LiPF 4 (C 2 O 4 ) (LiFOP), LiNO 3 , and mixtures thereof.
11. The lithium-based battery as defined in claim 8 , wherein the negative electrode is pre-lithiated with a lithium metal or a lithium salt selected from the group consisting of LiPF 6 , LiBF 4 , LiClO 4 , LiN(SO 2 CF 3 ) 2 (LiTFSI), LiB(C 2 O 4 ) 2 (LiBOB), LiBF 2 (C 2 O 4 ) (LiODFB), LiN(SO 2 F) 2 (LiFSI), LiPF 3 (C 2 F 5 ) 3 (LiFAP), LiPF 4 (CF 3 ) 2 , LiPF 3 (CF 3 ) 3 , LiPF 4 (C 2 O 4 ) (LiFOP), LiNO 3 , and a combination thereof.
12. The lithium-based battery as defined in claim 8 , wherein the silicon core has a diameter ranging from about 10 nm to about 20 nm, and the hard carbon coating has a thickness ranging from about 2 nm to about 20 nm.
13. The lithium-based battery as defined in claim 8 , wherein the negative electrode has a porosity ranging from about 30% to about 80%.
14. A negative electrode material, consisting of:
an active material, including:
a silicon core selected from the group consisting of Si, SiO 2 , SiO x (0<x<2), a silicon alloy, and a combination thereof; and
a hard carbon coating formed on the silicon core;
a non-fluorinated binder selected from the group consisting of sodium alginate and polyacrylic acid, wherein at least some of the non-fluorinated binder is chemically bound to the hard carbon coating: and a conductive filler;
wherein a loading of the active material in the negative electrode material is greater than 2 mg/cm 2 .
15. The negative electrode material as defined in claim 1 , wherein the hard carbon coating is formed from a carbon coating precursor comprising a phenolic compound, an aldehyde, a nitrogen containing compound, or combinations thereof.
16. The negative electrode material as defined in claim 15 , wherein the phenolic compound is selected from the group consisting of: phenol, resorcinol, catechol, hydroquinone, phloroglucinol, and combinations thereof; the aldehyde is selected from the group consisting of: formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, benzaldehyde, cinnamaldehyde, and combinations thereof; and the nitrogen containing compound is selected from the group consisting of: melamine, urea, ammonia, and combinations thereof.
17. The negative electrode material as defined in claim 8 , wherein the hard carbon coating is formed from a carbon coating precursor comprising a phenolic compound, an aldehyde, a nitrogen containing compound, or combinations thereof.
18. The negative electrode material as defined in claim 17 , wherein the phenolic compound is selected from the group consisting of: phenol, resorcinol, catechol, hydroquinone, phloroglucinol, and combinations thereof; the aldehyde is selected from the group consisting of: formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, benzaldehyde, cinnamaldehyde, and combinations thereof; and the nitrogen containing compound is selected from the group consisting of: melamine, urea, ammonia, and combinations thereof.
19. The negative electrode material as defined in claim 14 , wherein the hard carbon coating is formed from a carbon coating precursor comprising: a phenolic compound, and aldehyde, a nitrogen containing compound, or combinations thereof.
20. The negative electrode material as defined in claim 19 , wherein the phenolic compound is selected from the group consisting of: phenol, resorcinol, catechol, hydroquinone, phloroglucinol, and combinations thereof; the aldehyde is selected from the group consisting of: formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, benzaldehyde, cinnamaldehyde, and combinations thereof; and the nitrogen containing compound is selected from the group consisting of: melamine, urea, ammonia, and combinations thereof.