“…12,16 This mechanism is confirmed by many recent reports, such as of TiO 2 arrays on Ti substrates, a-Fe 2 O 3 arrays on Ti foils, Cu nanowalls on Fe-Co-Ni substrates, C/ZnO on Ni substrates, etc. 11,12,16,[23][24][25][26][27][28] Third, high surface-to-volume ratio and porous structures of NNs can facilitate the delivery of Li + and electrons to the surface. 4,7,8,29 Also, porous structures can provide ample space for lithium storage and accommodate the strain of volume change during lithiation and delithiation.…”