Abstract: The present application provides a separator for a secondary battery and a preparation method thereof, as well as a secondary battery and an electrical apparatus including the separator. The separator of the present application includes a porous substrate and a coating disposed on at least one surface of the porous substrate. The coating includes nanocellulose, the nanocellulose includes modifying groups, and the modifying groups include at least one of sulfonic acid groups, boric acid groups, and phosphoric acid groups.

Abstract: Present disclosure describes a method for low power communication between smart devices, including data transmission and control. The method for communicating with a smart device, includes following steps: waking up from a sleep mode periodically; performing an incoming transmission signal detection at a first frequency after waking up from the sleep mode; determining if an incoming transmission signal is detected; determining if at least part of a wake message is received, based on the determination that the incoming transmission signal is detected; determining if the at least part of the wake message is associated with the device, based on the determination that the at least part of the wake message is received; and switching to a second frequency for communication, based on the determination that the at least part of the wake message is associated with the device.