A flexible cyanometallate coordination polymer electrode for electrochemical dual-mode seawater energy extraction

Auto-switchable power supply systems on the basis of Prussian blue (PB) coordination polymers can smartly tackle both high energy and high power electricity requirements in seawater. To adapt to the complex underwater conditions, it is very important to make the coordination polymer electrode flexible. In this study, we succesfully grew a PB film on a carbon felt. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) confirmed that the PB layer was about 500 ± 50 nm in thickness. The electrochemical modification of the carbon felt guaranteed a strong coating of the PB layer. The obtained electrode worked effectively under bending and in vigorously flowing water. This PB coating was not detached during working under mechanical deformation. Both high-energy and high-power modes were realized in this system even when the PB electrode was deformed, permitting this seawater energy extraction system to support several electronic devices.