This paper describes the syntheses
and electrochemical properties
of a new niobate compound, aluminum niobate (AlNb11O29), for Li+ storage. AlNb11O29-microsized particles and nanowires were synthesized based on the
solid-state reaction and solvothermal methods, respectively. In situ
X-ray diffraction results confirmed the intercalating mechanism of
Li+ in AlNb11O29 and revealed its
high structural stability against cycling. The AlNb11O29 nanowires with a novel bamboo-like morphology afforded a
large interfacial area and short charge transport pathways, thus leading
to the observed excellent electrochemical properties, including high
reversible Li+-storage capacity (266 mA h g–1), safe operating potential (around 1.68 V), and high initial Coulombic
efficiency (93.3%) at 0.1 C. At a very high rate (10 C), the AlNb11O29 nanowires still exhibited a capacity as high
as 192 mA h g–1, indicating their good rate capability.
In addition, at 10 C, 96.3% capacity was retained over 500 cycles,
indicating superior cycling stability. A full cell fabricated with
AlNb11O29 nanowires as the anode and LiNi0.5Mn1.5O4 microparticles as the cathode
delivered a high energy density of 390 W h kg–1 at
0.1 C. This work suggests that the AlNb11O29 nanowires hold a great promise for the development of high-performance
lithium-ion batteries for large-scale energy-storage applications.