Zinc alkaline secondary battery including anchored electrolyte additives

Abstract

A zinc alkaline secondary battery includes a positive electrode, a negative electrode including a multi-valent oxide species, a separator system disposed between the electrodes, and an alkaline electrolyte in contact with the negative electrode. The alkaline electrolyte includes hexametaphosphate salt and zinc acetate. Ligands from the hexametaphosphate salt and zinc acetate are anchored to the negative electrode via chelation sites created by the multi-valent oxide species.

1 . A zinc alkaline secondary battery comprising:
 a positive electrode;   a negative electrode including a multi-valent oxide species;   a separator system disposed between the electrodes; and   an alkaline electrolyte in contact with the negative electrode and including hexametaphosphate salt and zinc acetate such that the alkaline electrolyte has a utilization for C-rates from C/6 to 10 greater than an otherwise same alkaline electrolyte without hexametaphosphate salt, without zinc acetate, or without hexametaphosphate salt and zinc acetate, ligands from the hexametaphosphate salt and zinc acetate being anchored to the negative electrode via chelation sites created by the multi-valent oxide species.   
     
     
         2 . The zinc alkaline secondary battery of  claim 1 , wherein a concentration of the hexametaphosphate salt is less than 0.004 molar. 
     
     
         3 . The zinc alkaline secondary battery of  claim 1 , wherein a concentration of the zinc acetate is less than 0.4 molar. 
     
     
         4 . The zinc alkaline secondary battery of  claim 1 , wherein the multi-valent oxide species includes bismuth, indium, tin, titanium, or a combination thereof. 
     
     
         5 . The zinc alkaline secondary battery of  claim 1 , wherein the multi-valent oxide species are 2% to 25% by dry active mass of the negative electrode. 
     
     
         6 . The zinc alkaline secondary battery of  claim 1 , wherein the alkaline electrolyte further includes hydroxide. 
     
     
         7 . The zinc alkaline secondary battery of  claim 6 , wherein the hydroxide is potassium hydroxide, cesium hydroxide, indium hydroxide, lithium hydroxide, ruthenium hydroxide, or sodium hydroxide. 
     
     
         8 . The zinc alkaline secondary battery of  claim 1 , wherein the alkaline electrolyte includes borate. 
     
     
         9 . The zinc alkaline secondary battery of  claim 1 , wherein the alkaline electrolyte includes zinc oxide. 
     
     
         10 . The zinc alkaline secondary battery of  claim 1 , wherein the alkaline electrolyte includes a dispersant. 
     
     
         11 . The zinc alkaline secondary battery of  claim 1 , wherein the negative electrode includes a borate salt, calcium hydroxide, calcium oxide, calcium zincate, strontium hydroxide, strontium oxide, strontium zincate, zinc oxide, or a combination thereof. 
     
     
         12 . The zinc alkaline secondary battery of  claim 1 , wherein the positive electrode is a manganese dioxide, nickel hydroxide, oxygen, or silver electrode.