Free-standing active material/carbon nanomaterial network film as light-weight and high-power electrodes for lithium ion batteries
An electrode includes a first free-standing carbon network, an active material deposited above the first free-standing carbon network, and a second free-standing carbon network covering the active material. The first and second carbon networks are a binder, a conductive additive and a current collector to the electrode.
1. An electrode, comprising:
a first carbon network;
a layer deposited above the first carbon network, the layer including an active material; and
a second carbon network covering the layer, wherein the first and second carbon networks are a binder, a conductive additive and a current collector to the electrode.
2. The electrode of claim 1 , wherein the active material comprises LiNi 0.5 Mn 1.5 O 4 , and the first and second carbon networks are continuous and porous.
3. The electrode of claim 2 , wherein the first and second carbon networks comprise carbon nanofibers.
4. The electrode of claim 3 , wherein the layer comprises carbon nanofibers into which LiNi 0.5 Mn 1.5 O 4 is embedded, particles of LiNi 0.5 Mn 1.5 O 4 are connected by the carbon nanofibers, and the electrode consists of carbon nanofibers and LiNi 0.5 Mn 1.5 O 4 .
5. The electrode of claim 4 , wherein the carbon nanofibers in the layer are a binder, a conductive additive and a current collector to the electrode.
6. The electrode of claim 2 , wherein the first and second carbon networks comprise carbon nanotubes, and the electrode is flexible.
7. The electrode of claim 1 , wherein the electrode provides a specific capacity of not less than 65 mAh/g at a current rate of 20 C.
8. The electrode of claim 1 , wherein a polarization resistance of the electrode is less than 0.2 ohm/g.
9. The electrode of claim 1 , wherein a weight percentage of the active material to the weight of the electrode is at least 0.45%.
10. The electrode of claim 1 , wherein the electrode is configured to deliver a capacity of more than 110 mAh/g after 100 charging and discharging at 5 C.
11. A lithium-ion battery comprising the electrode of claim 1 .
12. A method of forming an electrode, the method comprising:
depositing a carbon material using a first solution comprising the carbon material to obtain a first layer of a carbon network;
depositing a active material and the carbon material using a solution mixture to form a composite film above the first layer of the carbon network, and
depositing the carbon material using a second solution of the carbon material to obtain a second layer of the carbon network above the composite film, wherein the first layer of the carbon network, the second layer of the carbon network are a binder, a conductive additive and a current collector to the electrode.
13. The method of claim 12 , wherein the carbon network comprises a carbon nanomaterial.
14. The method of claim 13 , wherein the carbon nanomaterial comprises carbon nanofibers.
15. The method of claim 13 , wherein the carbon nanomaterial comprises carbon nanotubes.
16. The method of claim 12 , wherein the active material comprises LiNi 0.5 Mn 1.5 O 4 .
17. A lithium-ion battery having a flexible electrode formed using the method of claim 15 .
18. A lithium-ion battery formed using the method of claim 16 , wherein the electrode provides a specific capacity of not less than 65 mAh/g at a current rate of 20 C.
19. A lithium-ion battery formed using the method of claim 16 , wherein the electrode is configured to deliver a capacity of more than 110 mAh/g after 100 charging and discharging at 5 C.
20. A lithium-ion battery formed using the method of claim 16 , wherein a weight percentage of the active material to the weight of the electrode is at least 0.45%.
21. A lithium-ion battery comprising an anode and a cathode, wherein the anode comprises:
a first carbon network;
a layer deposited above the first carbon network, the layer including an active material; and
a second carbon network covering the layer, the first and second carbon networks are a binder, a conductive additive and a current collector to the anode, and wherein the cathode comprises:
a third carbon network;
a second layer deposited above the third carbon network, the second layer including the active material; and
a fourth carbon network covering the second layer, the third and fourth carbon networks are a binder, a conductive additive and a current collector to the cathode.