Alkaline electrochemical cell with a blended zinc powder
View Patent ↗An electrochemical cell with a blended zinc powder is disclosed. The blended zinc powder includes selected portions of a first zinc powder and a second zinc powder. In a preferred embodiment, the first and second powders are divided into groups based on ranges in their particle size distribution. Particle characteristics such as roughness and elongation are used to selected groups of both powders that are combined to produce the blended zinc powder. The blended zinc powders enable battery manufacturers to maximize the cell's run time while minimizing the cost of the zinc.
1. An electrochemical cell comprising a first electrode including a mixture of zinc powders, said mixture comprising zinc particles from a first powder and zinc particles from at least a second powder, wherein the range of particle sizes in the first powder and the range of particle sizes in the second powder do not overlap, wherein said mixture of zinc powders have a multimodal particle size distribution and wherein the first powder's particles have either: a) an average roughness index value that is at least 2.0 percent higher than an average roughness index value of the second powder's particles or b) an average elongation index value that is at least 3.0 percent higher than an average elongation index value of the second powder's particles.
2. The electrochemical cell of claim 1 , wherein said first powder's particles have a particle size less than 75 microns and said second powder's particles have a particle size greater than 75 microns.
3. The electrochemical cell of claim 1 , wherein said first powder's particles have a particle size between 75 microns and 150 microns and said second powder's particles comprise a first group having a particle size greater than 150 microns and a second group having a particle size less less than 75 microns.
4. The electrochemical cell of claim 1 , wherein said first powder's particles have a particle size greater than 150 microns and said second powder's particles have a particle size less than 150 microns.
5. The electrochemical cell of claim 1 , wherein the first powder's particles have an average elongation index value that is at least 3.5 percent higher than an average elongation index value of the second powder's particles.
6. The electrochemical cell of claim 1 , wherein the first powder's particles have an average elongation index value that is at least 4.0 percent higher than an average elongation index value of the second powder's particles.
7. The electrochemical cell of claim 1 , wherein said first powder is formed in a first powder manufacturing process, said second powder is produced in a second powder manufacturing process and said first and second powder manufacturing processes are different from one another.
8. The electrochemical cell of claim 7 , wherein said powder manufacturing processes are selected from the group consisting of centrifugal atomization, gas atomization, and impulse atomization.
9. The electrochemical cell of claim 1 , wherein said first powder and said second powder are zinc alloys comprising the same chemical elements.
10. The electrochemical cell of claim 9 , wherein the quantities of said chemical elements in said alloys are the same.