fig9

Figure 9. (A) SEM images of Sb@3D Cu NWAs from (a and b) a top view, (c) a side view, and (d and e) an enlarged top view. Energy dispersive X-ray spectroscopy maps for elements (f) Cu and (g) Sb; (B) Cyclability curves; (C) Rate performance. Quoted with permission from Fan et al.^[94]; (D) Structural evolution of bulk Bi flakes. Secondary-electron images recorded at low magnification; (E) Changes in specific capacity of Na-Bi half-cells measured at various C-rates using an electrolyte containing DME; (F) Changes in the specific capacity of the Na-Bi half-cell with DME and EC/DEC solvent measured at 20.0 C as a function of the battery cycle. Quoted with permission from Kim et al.^[97]. SEM: Scanning electron microscope; Sb@3D Cu NWAs: a thin film of Sb is electrochemically deposited on 3D Cu NWAs; DME: dimethoxy-ethane; EC: ethylene carbonate; DEC: diethyl carbonate.