Low concentration additives for iron negative electrodes

A method of fabricating an electrode for an electrochemical cell, the method comprising:

• forming a feedstock including an iron-containing active material and at least one of an additive or a precursor of the additive, the additive reactive to inhibit hydrogen evolution from the electrode under electrochemical cycling;
• processing the feedstock into a composite, the additive distributed relative to the iron-containing active material in the composite, and additive in a concentration greater than about 10 and less than about 10,000 atoms of additive per million atoms of iron in the composite;
• and
• shaping the composite into a green body of the electrode.

A method of fabricating an electrode for an electrochemical cell, the method comprising:

• forming a green body including an iron-containing active material;
• positioning an additive on at least one surface of the green body, the additive reactive to inhibit hydrogen evolution from the electrode under electrochemical operation;
• and
• with the additive positioned on the at least one surface of the green body, wicking the additive into the green body.

A method of static discharge testing of an electrochemical cell, the method comprising:

• cycling the electrochemical cell through at least two baseline cycles, each baseline cycle including charging the electrochemical cell from a lower voltage limit to a predetermined target capacity and discharging the electrochemical cell from the predetermined target capacity to the lower voltage limit;
• measuring a first Coulombic efficiency of the electrochemical cell following the at least two baseline cycles;
• cycling the electrochemical cell through a comparison cycle including
• charging the electrochemical cell from the lower voltage limit to the predetermined target capacity,
• with the electrochemical cell charged to the predetermined target capacity, interrupting electric current to the electrochemical cell for a predetermined rest period, and
• at the end of the predetermined rest period, discharging the electrochemical cell to the lower voltage limit;
• measuring a second Coulombic efficiency following the comparison cycle;
• and
• based on the first Coulombic efficiency and the second Coulombic efficiency, determining a change in discharge capacity of the electrochemical cell.