POWER SUPPLY DEVICE AND METHOD, AND ELECTRONIC DEVICE

The present disclosure discloses an apparatus and a method for power supply and an electronic device. The apparatus for power supply includes a first battery and a second battery connected in series, a first voltage step-down module and a control module. The first battery is a silicon negative lithium ion battery. The control module is configured to control the first voltage step-down module to step down the voltage of the first battery and the second battery connected in series to supply power based on power supply demands, during a power supply process. By using a silicon negative lithium ion battery connected in series with other batteries, charging speed can be increased comparing with using one battery, and energy density can be improved comparing with using a silicon negative lithium ion battery.