Alkaline cells having high capacity
View Patent ↗The present invention relates to a high capacity electrochemical cell including an anode, a cathode, and a separator disposed between the anode and cathode. The anode is configured to operate in combination with a quantity of an oxide of copper in the cathode. The cell is capable of operating at a discharge voltage greater than 1.05 volts for at least an initial 5% of a cell discharge period at a current density of at least 5 mA/g, and can include a cathode active material that includes an oxide of copper.
1. An electrochemical cell comprising:
an anode including zinc particles, at least 70% of the particles having a size distributed within a 150 micron or less size range, wherein the particle size distribution has a single mode, the mode being between about 100 microns and about 300 microns;
a cathode containing an oxide of copper; and
a separator disposed between the anode and cathode.
2. The electrochemical cell as recited in claim 1 , wherein at least 90% of the zinc particles have a size distributed around a particle size of 100 microns.
3. The electrochemical cell as recited in claim 1 , wherein at least 90% of the zinc particles have a size distributed around a particle size of 175 microns.
4. The electrochemical cell as recited in claim 1 , wherein at least 90% of the zinc particles have a size distributed around a particle size of 250 microns.
5. The electrochemical cell as recited in claim 1 , wherein at least 90% of the zinc particles have a size distributed around a particle size of 300 microns.
6. The electrochemical cell as recited in claim 1 , further comprising an electrolyte concentration substantially between 25% and 34% KOH.
7. The electrochemical cell as recited in claim 1 , wherein the anode further comprises a zinc oxide concentration substantially in the range of 0.5% and 6%.
8. The electrochemical cell as recited in claim 1 , wherein the cathode further comprises a metal oxide additive.
9. The electrochemical cell as recited in claim 8 , wherein the additive further comprises an electrode material, the electrode material providing a higher operating voltage vs. zinc in an initial portion of discharge compared to the oxide of copper.
10. The electrochemical cell as recited in claim 9 , wherein the additive is selected from the group consisting of EMD, CMD, NiO, NiOOH, Cu(OH) 2 , Cobalt Oxide, PbO 2 , AgO, Ag 2 O, AgCuO 2 , Cu 2 Mn 2 O 4 , Cu 2 Ag 2 O 4 , Cu 2 Ag 2 O 3 , and combinations thereof.
11. The electrochemical cell as recited in claim 1 , wherein the oxide of copper is identified generally by M x Cu y O z , wherein:
M is any element capable of producing mixed oxide compounds or complexes;
1<x<5;
1<y<5; and
1<z<20.
12. The electrochemical cell as recited in claim 11 , wherein M is selected from the group consisting of Mn, Ni, Co, Fe, Sn, V, Mo, Pb, and Ag.
13. The electrochemical cell as recited in claim 11 , wherein the copper based mixed oxide material further comprises an additional metal.
14. The electrochemical cell as recited in claim 11 , wherein the copper based mixed oxide material further comprises an additional metal “A” identified in a compound AM x Cu y O z .
15. The electrochemical cell as recited in claim 14 , wherein “A” is selected from the group consisting of Li, Na, K, Rb, Cs, Ca, Mg, Sr and Ba.
16. The electrochemical cell as recited in claim 1 , wherein the cathode further comprises an additive that, when used alone, has a lower discharge voltage than the oxide.
17. The electrochemical cell as recited in claim 1 , wherein the cathode further comprises an additive that, when used alone, has a lower discharge voltage than the oxide, wherein the combined oxide and additive produce a higher discharge voltage than either the oxide or the additive alone.
18. The electrochemical cell as recited in claim 17 , wherein the additive is selected from the group consisting of elemental sulfur, selenium, tellurium, and compounds thereof.
19. The electrochemical cell as recited in claim 18 , wherein the additive comprises a sulfide of copper.
20. The electrochemical cell as recited in claim 19 , wherein the sulfide of copper comprises CuS.
21. The electrochemical cell as recited in claim 20 , wherein the cathode further comprises a molar ratio of CuO/CuS substantially between 0.5:1 and 1.5:1.
22. The electrochemical cell as recited in claim 21 , wherein the molar ratio is substantially between 0.8:1 and 1.2:1.
23. The electrochemical cell as recited in claim 20 , wherein the molar ratio is substantially 1:1.
24. The electrochemical cell as recited in claim 11 , wherein substantially all fluid communication between the anode and the cathode is through the separator, the separator being adapted to effectively limit the migration of at least one anode-fouling soluble species through the separator from the cathode to the anode.
25. The electrochemical cell as recited in claim 11 , wherein the cathode further comprises graphite.
26. The electrochemical cell as recited in claim 1 , wherein the cathode further comprises a copper based mixed oxide material identified generally by M x Cu y O z , wherein:
M is any element capable of producing mixed oxide compounds or complexes;
1≦x≦5;
1≦y≦5; and
1≦z≦20.
27. The electrochemical cell as recited in claim 1 , wherein the cathode additionally contains a cathode active material that has an operating voltage higher than the oxide of copper, and a conductivity enhancer.
28. An electrochemical cell comprising:
an anode including zinc particles, at least 70% of the particles having a size distributed within a 200 micron size range, wherein the particle size distribution has a single mode, the mode being between about 100 microns and about 300 microns, wherein at least 90% of the particles have a size distributed around a particle size selected from the group consisting of 100 microns, 175 microns, 250 microns and 300 microns;
a cathode containing an oxide of copper; and,
a separator disposed between the anode and cathode.