Fig. 1: Voltage-controlled electrochemical growth of cobalt networks.

a The illustration of the setup for voltage-controlled electrochemical growth in the trapped thin layer of electrolyte. The Peltier element and the heat sink are used to control the temperature of the cell to freeze the electrolyte or melt the ice of the electrolyte. The signal generator and the laptop program a specific voltage pattern for electrodeposition. b SEM micrographs of the network deposited in the trapped thin layer of electrolyte. The white arrow indicates the direction of network growth. The right panel is the enlarged micrograph of the orange dotted box in the left panel. c The programmed altering voltage applied to deposit the network shown in (b). d The surface plot of the network obtained by AFM measurement. e The height profiles corresponding to the purple and cyan dotted lines in (d). f Bright-field TEM micrograph of the electrodeposited network. g, The electron diffraction pattern of the selected area X, as marked in (f). The diffraction obtained in the triangular pattern shows the same structure, as shown in the Supplementary Note 7. Source data are provided as a Source Data file.