Fabrication and Shell Optimization of Synergistic TiO2-MoO3 Core-Shell Nanowire Array Anode for High Energy and Power Density Lithium-Ion Batteries

摘要

A novel synergistic TiO2-MoO3 (TO-MO) core-shell nanowire array anode has been fabricated via a facile hydrothermal method followed by a subsequent controllable electrodeposition process. The nano-MoO3 shell provides large specific capacity as well as good electrical conductivity for fast charge transfer, while the highly electrochemically stable TiO2 nanowire core (negligible volume change during Li insertion/desertion) remedies the cycling instability of MoO3 shell and its array further provides a 3D scaffold for large amount electrodeposition of MoO3. In combination of the unique electrochemical attributes of nanostructure arrays, the optimized TO-MO hybrid anode (mass ratio: ca. 1:1) simultaneously exhibits high gravimetric capacity (ca. 670 mAh g(-1); approaching the hybrid's theoretical value), excellent cyclability (>200 cycles) and good rate capability (up to 2000 mA g(-1)). The areal capacity is also as high as 3.986 mAh cm(-2), comparable to that of typical commercial LIBs. Furthermore, the hybrid anode was assembled for the first time with commercial LiCoO2 cathode into a Li ion full cell, which shows outstanding performance with maximum power density of 1086 W kg(total) (-1) (based on the total mass of the TO-MO and LiCoO2) and excellent energy density (285 Wh kg(total) (-1)) that is higher than many previously reported metal oxide anode-based Li full cells.