CHARGE AND DISCHARGE METHOD FOR NONAQUEOUS ELECTROLYTE SECONDARY BATTERY, AND CHARGE AND DISCHARGE SYSTEM FOR NONAQUEOUS ELECTROLYTE SECONDARY BATTERY

A charging and discharging method for a non-aqueous electrolyte secondary battery. The battery includes a positive electrode, a negative electrode including a negative electrode current collector, and a non-aqueous electrolyte, in which a lithium metal deposits on the negative electrode during charge, and the lithium metal dissolves in the non-aqueous electrolyte during discharge. The method includes a charging step, and a discharging step performed after the charging step. The charging step includes a first step of performing a constant-current charging at a first current I1 having a current density of 1.0 mA/cm2 or less, and a second step of performing a constant-current charging at a second current I2 larger that the first current I1, after the first step. In the discharging step, an amount of electricity corresponding to 20% or more and 80% or less of a full charge amount is discharged.