Non-aqueous electrochemical cell having a mixture of at least three cathode materials therein
View Patent ↗The present disclosure relates generally to a high capacity cathode material suitable for use in a non-aqueous electrochemical cell that comprises a mixture of at least three different cathode materials, and more specifically a mixture of fluorinated carbon, an oxide of copper and an oxide of manganese. The present disclosure additionally relates to a non-aqueous electrochemical cell comprising such a cathode material and, in particular, to such a non-aqueous electrochemical cell that can deliver a higher capacity than a conventional cell, and/or that possesses an improved end-of-life indication.
1. A non-aqueous electrochemical cell comprising:
an anode;
a cathode comprising a cathode material comprising a mixture of fluorinated carbon, an oxide of copper, and an oxide of manganese;
a separator disposed between the anode and the cathode; and,
a non-aqueous electrolyte which is in fluid communication with the anode, the cathode and the separator,
wherein:
the concentration of the fluorinated carbon in the cathode material mixture is between about 60 wt % and about 95 wt %, based on the total weight of the cathode mixture;
the fluorinated carbon is a mixture of materials having the formulas (CF x1 )n and (CF x2 )m, where:
x1 is between about 0.8 to about 1.2,
x2 is between about 0.4 to about 0.8,
n is between about 1 to about 5, and
m is between about 1 to about 5;
(CF x1 )n and (CF x2 )m are distinct materials from each other;
a ratio of (CF x1 ) to (CF x2 ) is from about 5:1 to about 1:5; and
a ratio of the oxide of copper to the oxide of manganese or a ratio of the oxide of manganese to the oxide of copper is from about 1:1 to 5:1.
2. The non-aqueous electrochemical cell of claim 1 , wherein the oxide of copper is CuO, Cu 2 O, or a mixture thereof.
3. The non-aqueous electrochemical cell of claim 1 , wherein the oxide of manganese is MnO 2 .
4. The non-aqueous electrochemical cell of claim 1 , wherein the weight ratio of the oxide of manganese to the oxide of copper is between about 1:1 and about 3:1.
5. The non-aqueous electrochemical cell of claim 1 , wherein the weight ratio of the oxide of copper to the oxide of manganese is between about 1:1 and about 4.5:1.
6. The non-aqueous electrochemical cell of claim 1 , wherein the particle size of the oxide of copper is between about 15 and about 45 nanometers.
7. The non-aqueous electrochemical cell of claim 1 , wherein the concentration of the fluorinated carbon in the cathode material mixture is at least about 50 wt %, based on the total weight of the cathode mixture.
8. The non-aqueous electrochemical cell of claim 1 , wherein the non-aqueous electrolyte comprises an organic solvent selected from the group consisting of dimethyl carbonate (DMC), diethyl carbonate, 1,2-dimethoxyethane (DME), tetrahydrofuran (THF), methyl acetate (MA), diglyme, triglyme, tetraglyme, propylene carbonate (PC), ethylene carbonate (EC), acetonitrile, dimethyl sulfoxide, dimethyl formamide, dimethyl acetamide, gamma-butyrolactone (GBL), and N-methyl-pyrrolidinone (NMP), or a mixture of two or more thereof.
9. The non-aqueous electrochemical cell of claim 8 , wherein the non-aqueous electrolyte comprises a salt having a formula MM′F 6 or MMF 4 , wherein M is an alkali metal that is the same as at least one of the metals in the anode and M′ is an element selected from the group consisting of phosphorous, arsenic, antimony and boron.
10. The non-aqueous electrochemical cell of claim 9 , wherein the salt is selected from the group consisting of LiPF 6 , LiAsF 6 , LiSbF 6 , LiBF 4 , LiClO 4 , LiAlCl 4 , LiGaCl 4 , LiC(SO 2 CF 3 ) 3 , LiB(C 6 H 4 O 2 ) 2 , LiN(CF 3 SO 2 ) 2 and Li(CF 3 SO 3 ), as well as mixtures thereof.
11. The non-aqueous electrochemical cell of claim 10 , wherein the non-aqueous electrolyte comprises a salt, the concentration of the salt in the organic solvent being in the range of between about 0.5 M and about 2.5 M.
12. The non-aqueous electrochemical cell of claim 1 , wherein the anode comprises a metal selected from Group IA or Group IIA of the Periodic Table of the Elements.
13. The non-aqueous electrochemical cell of claim 12 , wherein the anode comprises a metal selected from the group consisting of lithium, magnesium, sodium, and potassium.
14. The non-aqueous electrochemical cell of claim 13 , wherein the anode comprises an alloy or intermetallic compounds selected from the group consisting of Li—Mg, Li—Al, Li—Al—Mg, Li—Si, Li—B and Li—Si—B.
15. The non-aqueous electrochemical cell of claim 1 , wherein the cell exhibits a volumetric specific capacity of at least about 2.7 Ah/cm 3 at about 2.0 volts.
16. The non-aqueous electrochemical cell of claim 1 , wherein the cell exhibits a volumetric specific capacity of at least about 2.9 Ah/cm 3 at about 1.5 volts.
17. The non-aqueous electrochemical cell of claim 1 , wherein the cathode material comprises about 81 wt % of the fluorinated carbon, and about 12 wt % of a mixture that consists essentially of an oxide of copper and an oxide of manganese, about 3 wt % binder material, and about 4 wt % conductive additive, based on the total weigh of the cathode material.
18. The non-aqueous electrochemical cell of claim 1 , wherein the cathode material mixture of fluorinated carbon, and oxide of copper and an oxide of manganese exhibits a volumetric specific capacity that is at least about 10% or greater than a volumetric specific capacity of a fluorinated carbon cathode material alone.
19. The non-aqueous electrochemical cell of claim 1 , wherein the cathode material mixture of fluorinated carbon, and oxide of copper and an oxide of manganese exhibits an end-of-life indication that is at least about 5% greater than an end-of-life indication of a fluorinated carbon cathode material alone.