Potassium ion additives for voltage control and performance improvement in nonaqueous cells

An electrochemical cell, comprising:

• a lithium anode or a lithium alloy anode;
• a solid cathode comprising one or more of the group consisting of FeS.sub.2, MnO.sub.2 and TiS.sub.2 ;
• and
• a nonaqueous, liquid electrolyte including an organic solvent, an electro-chemically active amount of a primary salt, and about 0.005 to 0.1 mol/l of a potassium salt.

An electrochemical cell, comprising:

• a lithium anode or a lithium alloy anode;
• a solid active metal cathode;
• and
• a nonaqueous, liquid electrolyte including an organic solvent, an electrochemically active amount of a primary salt selected from the group consisting of lithium halides, lithium hexafluorophosphates, lithium hexafluoroarsenates, lithium trifluoromethanesulfonate, and combinations thereof, and more than 0.001 mol/l of a potassium salt additive selected from the group consisting of potassium trifluoromethanesulfonate, potassium carbonate, potassium tetrafluoroborate, potassium tetraalkylborates, potassium tetraphenylborates, potassium halides, potassium hexafluorophosphate, potassium perfluoroalkylsulfonates, and combinations thereof.

An electrochemical cell, comprising:

• a lithium anode or a lithium alloy anode;
• a solid cathode comprising iron disulfide;
• and
• a nonaqueous, liquid electrolyte including an organic solvent, about 0.5 to 2 mol/l of a lithium salt selected from the group consisting of lithium halides, lithium hexafluorophosphate, lithium hexafluoroarsenate, lithium tetrafluoroborates, lithium trifluoromethanesulfonate, and combinations thereof, and about 0.005 to 0.1 mol/l of a potassium salt selected from the group consisting of potassium trifluoromethanesulfonate, potassium carbonate, potassium tetrafluoroborate, potassium tetraalkylborates, potassium tetraphenylborates, potassium halides, potassium hexafluorophosphate, potassium perfluoroalkylsulfonates, and combinations thereof.