Replenished negative electrodes for secondary batteries

A method of cycling a secondary battery between a charged state and a discharged stage, the secondary battery comprising a negative electrode, a positive electrode, a microporous separator between the negative and positive electrodes permeated with a carrier ion-containing electrolyte in ionic contact with the negative and positive electrodes, and a controller, wherein

• the positive electrode comprises a cathodically active material and has a coulombic capacity for the carrier ions,
• the negative electrode comprises anodically active silicon or an alloy thereof and has a coulombic capacity for the carrier ions that exceeds the positive electrode coulombic capacity,
• the controller is programmed with a predefined cell end of charge voltage Vcell,eoc value and a predefined cell end of discharge voltage Vcell,eod value, and
• the positive electrode has an end of discharge voltage Vpos,eod and the negative electrode has an end of discharge voltage Vneg,eod when the cell is at the predefined Vcell,eod, the value of Vpos,eod corresponds to a voltage at which the state of charge of the positive electrode is at least 95% of its coulombic capacity and Vneg,eod is at least 0.4 V (vs Li) but less than 0.9 V (vs Li),
• wherein the method comprises cycling the secondary battery by repeatedly charging the secondary battery to the charged state having a cell end of charge voltage that does not exceed the predefined Vcell,eoc value, and discharging the secondary battery to the discharged state having a cell end of discharge voltage that does not exceed the predefined Vcell,eod value.