A battery management apparatus, comprising: a measuring unit configured to measure voltages and currents of a battery cell while the battery cell is in operation, in a plurality of charging and discharging cycles of the battery cell; a control unit configured to estimate a capacity of the battery cell based on the current of the battery cell measured by the measuring unit for each charging and discharging cycle; and a storage unit configured to store: capacity-voltage differential profiles generated based on the voltages of the battery cell measured by the measuring unit and the capacities of the battery cell estimated by the control unit and charging and discharging C-rates for each charging and discharging cycle, wherein the control unit is configured to generate groups of charging and discharging cycles wherein within each group the corresponding charging and discharging cycles have the same charging and discharging C-rate stored in the storage unit, estimate a new capacity of the battery cell based on the current of the battery cell measured by the measuring unit during a new charging and discharging cycle and generate a new capacity-voltage differential profile based on the voltage measured by the measuring unit and the new capacity, select a predetermined group among the generated groups and diagnose a state of the battery cell according to a change pattern between the capacity-voltage differential profiles corresponding to the charging and discharging cycles of the selected predetermined group and the new capacity-voltage differential profile, wherein the predetermined group is a group of cycles having the same charging and discharging C-rate as the charging and discharging C-rate of the new charging and discharging cycle, among the generated groups, extract at least one of a first peak associated with loss of available lithium of the battery cell provided to the battery cell and a second peak associated with a positive electrode reaction area, in each capacity-voltage differential profile corresponding to the charging and discharging cycles included in the predetermined group, and diagnose a state of the battery cell according to a change pattern of at least one of the plurality of extracted first peaks and the plurality of extracted second peaks. a measuring unit configured to measure voltages and currents of a battery cell while the battery cell is in operation, in a plurality of charging and discharging cycles of the battery cell; a control unit configured to estimate a capacity of the battery cell based on the current of the battery cell measured by the measuring unit for each charging and discharging cycle; and a storage unit configured to store: capacity-voltage differential profiles generated based on the voltages of the battery cell measured by the measuring unit and the capacities of the battery cell estimated by the control unit and charging and discharging C-rates for each charging and discharging cycle, capacity-voltage differential profiles generated based on the voltages of the battery cell measured by the measuring unit and the capacities of the battery cell estimated by the control unit and charging and discharging C-rates for each charging and discharging cycle, wherein the control unit is configured to generate groups of charging and discharging cycles wherein within each group the corresponding charging and discharging cycles have the same charging and discharging C-rate stored in the storage unit, estimate a new capacity of the battery cell based on the current of the battery cell measured by the measuring unit during a new charging and discharging cycle and generate a new capacity-voltage differential profile based on the voltage measured by the measuring unit and the new capacity, select a predetermined group among the generated groups and diagnose a state of the battery cell according to a change pattern between the capacity-voltage differential profiles corresponding to the charging and discharging cycles of the selected predetermined group and the new capacity-voltage differential profile, wherein the predetermined group is a group of cycles having the same charging and discharging C-rate as the charging and discharging C-rate of the new charging and discharging cycle, among the generated groups, extract at least one of a first peak associated with loss of available lithium of the battery cell provided to the battery cell and a second peak associated with a positive electrode reaction area, in each capacity-voltage differential profile corresponding to the charging and discharging cycles included in the predetermined group, and diagnose a state of the battery cell according to a change pattern of at least one of the plurality of extracted first peaks and the plurality of extracted second peaks.