Magnetically Controlled On‐Demand Switching of Batteries

The integration of stimuli‐responsiveness into energy storage devices has become an attractive way to manage the operation of devices. Current stimuli approaches (light, chemical, and temperature) require transparent windows and specific systems, or are subject to the tolerant temperature of batteries, hampering their widespread applications. Herein, a fast and reversible on‐demand switching of batteries, which is realized by incorporating a magnetic control component, is reported. The component is capable of undergoing a reversible transition between electrical conduction and insulation over 500 cycles, showing superior cycling stability. Batteries with this component internally incorporated can retain excellent electrochemical performance in a wide potential window at normal conditions. More importantly, this approach can manage the operation of batteries in light of human requirements. The battery can shut down within 0.11 s of applying a magnetic field and rapidly resume a normal battery function under the magnetic field, showing an excellent response speed. Notably, this on‐demand switching behavior in batteries can be repeated over 25 times, excelling most reported switching batteries. The design combines fast and repeatable characteristics without sacrificing electrochemical performance, providing possibilities in advancing the development of smart electronics.