Electrochemical cells and methods of using thereof

An electrochemical cell assembly, comprising:

• an electrochemical cell, comprising:
• a housing,
• a negative active material disposed within a first electrode chamber of the housing, the negative active material comprising lead and/or lead sulfate;
• a positive active material disposed within a second electrode chamber of the housing, the positive active material comprising lead, lead sulfate, lead oxide, and/or lead dioxide;
• and
• a separator disposed in the housing between the first electrode chamber and the second electrode chamber to separate electrolytes in respective chambers;
• a first electrolyte reservoir for a first electrolyte in fluid communication with the electrochemical cell to pump the first electrolyte from the first electrolyte reservoir through the first electrode chamber during operation of the electrochemical cell based on a first process of a cell cycle of the electrochemical cell;
• a second electrolyte reservoir for a second electrolyte in fluid communication with the electrochemical cell to pump the second electrolyte from the second electrolyte reservoir through the first electrode chamber during operation of the electrochemical cell based on a second process of the cell cycle of the electrochemical cell;
• and
• wherein the first electrolyte having a different concentration of sulfuric acid from the second electrolyte.