Alkaline electrochemical cell with improved anode and separator components
An alkaline electrochemical cell includes a cathode, an anode which includes an anode active material, and a non-conductive separator disposed between the cathode and the anode, wherein from about 20% to about 50% by weight of the anode active material relative to a total amount of anode active material has a particle size of less than about 75 μm, and wherein the separator includes a unitary, cylindrical configuration having an open end, a side wall, and integrally formed closed end disposed distally to the open end.
1. An alkaline electrochemical cell comprising:
a cathode;
an anode comprising an anode active material; and
a non-conductive separator disposed between the cathode and the anode;
wherein:
from about 15% to about 60% by weight of the anode active material relative to a total amount of anode active material has a particle size of less than about 75 μm, and wherein greater than about 8% and less than about 20% by weight of the anode active material relative to the total amount of anode active material present in the anode gel has a particle size of greater than about 150 μm and less than 425 μm; and
the separator comprises a unitary, cylindrical configuration having an open end, a side wall, and integrally formed closed end disposed distally to the open end;
wherein the separator comprises a non-conductive, porous material; and
wherein the separator has a single layer wound twice and having a dry thickness of about 0.205 mm to about 0.245 mm.
2. The alkaline electrochemical cell of claim 1 , wherein the anode active material has an apparent density from about 2.62 g/cc to about 2.92 g/cc.
3. The alkaline electrochemical cell of claim 1 , wherein the anode active material comprises a zinc alloy comprising zinc, indium, and bismuth.
4. The alkaline electrochemical cell of claim 3 , wherein the zinc alloy comprises:
about 130 ppm to about 270 ppm of bismuth; and
about 130 ppm to about 270 ppm of indium.
5. The alkaline electrochemical cell of claim 3 , wherein the zinc alloy is present in the anode from about 62% to about 70% by weight, relative to the total weight of the anode.
6. The alkaline electrochemical cell of claim 3 , wherein the zinc alloy is present in the anode at about 63% by weight relative to the total weight of the anode.
7. An anode gel for an alkaline electrochemical cell, the anode gel comprising:
an anode active material, wherein from about 15% to about 60%, by weight relative to a total weight of anode active material has a particle size of less than about 75 μm, and wherein greater than about 8% and less than about 20% by weight of the anode active material relative to the total amount of anode active material present in the anode gel has a particle size of greater than about 150 μm and less than 425 μm;
an electrolyte; and
a gelling agent.
8. The anode gel of claim 7 , wherein the anode active material has an apparent density of from about 2.62 g/cc to about 2.92 g/cc.
9. The anode gel of claim 7 , wherein the electrolyte comprises an aqueous solution of potassium hydroxide.
10. The anode gel of claim 7 , wherein the electrolyte has a hydroxide concentration of about 32% or less.
11. The anode gel of claim 7 , wherein the anode active material comprises a zinc alloy comprising zinc, indium and bismuth.
12. The anode gel of claim 11 , wherein the zinc alloy comprises:
about 130 ppm to about 270 ppm of bismuth; and
about 130 ppm to about 270 ppm of indium.
13. The anode gel of claim 7 , wherein about 20% to about 50% by weight of the anode active material, relative to the total amount of anode active material, has a particle size of less than about 75 microns.
14. The anode gel of claim 13 , wherein the anode active material has an apparent density of about 2.62 g/cc to 2.92 g/cc.
15. The anode gel of claim 7 , wherein the anode active material comprises a zinc alloy and the amount of zinc alloy is in the anode is present from about 62% to about 70% by weight relative to a total weight of the anode.