Composite battery

The invention discloses a composite battery, and the battery comprises a battery unit, a capacitor unit, and a power management unit. The battery unit comprises a housing, an electrolyte placed in the housing, and a graphene layer which is disposed between the housing and the electrolyte. The capacitor unit is in series connection with the battery unit. The power management unit comprises a switch which is connected with the battery unit and the capacitor unit and is used for controlling the on/off of the battery unit and the capacitor unit, and also comprises a processor which is used for comparing a voltage of the battery unit with a preset voltage so as to control the switch. The battery can give consideration to the large-capacity stable utilization of the battery and the quick charging and discharging of a capacitor, and improves the overall power utilization efficiency. 种复合电池，包含电池单元、电容单元及电源管理单元。该电池单元包括壳体、填充于该壳体内的电解质及设置于该壳体与该电解质间的石墨烯层；该电容单元与该电池单元串联；该电源管理单元，包括分别与该电池单元及该电容单元电连接且用以控制该电池单元与该电容单元是否导通的开关，及用以比较