Zn_xGe_1–xO 3D Micronano Structures with Excellent Performance as Anode Material in Lithium Ion Battery

Abstract

As anode material used in power storage device, lithium ion battery (LIB) for example, ZnO has not been recognized as a promising candidate, although which shows advantages like environmental benign, low cost, and large reservation. Several problems, such as volume expansion, pulverization, and active substance detachment because of the particular lithiation kinetics, which result in very high irreversible capacity and following fading, can account for the present situation. Here in this work, we report the self-assembly of ZnxGe1-xO three-dimensional (3D) micronano structures and achieve enormous improvement on both recyclability and rate performance. After the 100th cycle, the capacity remains ∼690 mAh/g at the rate of 100 and ∼510 mA/g at the rate of 500 mAh/g. The capacity recovered rapidly even the rates alternating repeatedly between 50 mA/g and 3.5A/g. Ex situ observation reveals that substance detachment and nanoparticle agglomeration were avoided, benefiting from the firm 3D space configuration. As the Li(+) insertion, the 3D architectures fracture hierarchically with releasing the volume-expansion produced strain. Stable and smooth Li(+)/electrons path would form in these nanoparticles integrated microfragments, which act as the working unit free of further detachment. These facts demonstrate that ZnO based anode materials are anticipant to be good candidate in LIB device through rational design of advanced mirco-nano structures without introduction of carbon coating.

Millimeters long super flexible Mn5Si3@SiO2 electrical nanocables applicable in harsh environments

“…Synthesis and characterizations of Mn 5 Si 3 @SiO 2 nanocables. The sample was synthesized in a home-made horizontal tube furnace as previously demonstrated 30,31 . The growth of Mn 5 Si 3 core-shell nanowires proceeded in a molten Mn-Si-O glassy matrix ( Fig.…”

2D free-standing Ge-doped ZnO: excellent electron-emitter and excitation-power-dependent photoluminescence redshift

“…As characterized by TEM and analyzed in the growth part, we hypothesized that Ge may be distributed on the surface of the Zn x Ge 1Àx O particles in an amorphous state, because we did not nd Ge nanoparticles despite much effort having been made. 18 As is well recognized, Ge has very large Bohr exciton radius ($24 nm) and low work function, which is to say that both the connement effect and low surcial potential barrier would enhance the electron emission enormously. Noticeably, a Ge composite between adjacent Zn x Ge 1Àx O particles would also provide a smooth electron transport channel.…”

“…The sample synthesis was carried out in a self-designed and -built furnace as demonstrated previously. [18][19][20] In detail, a mixture of ZnO and C black (30 mg, atomic ratio 2 : 1) was put at the center of a polished ceramic sheet and 5 mg of GeO 2 was placed by the side. A piece of graphite sheet was placed 6 cm away from the GeO 2 powder.…”

Three dimensional self-assembly ZnSb nanowire balls with good performance as sodium ions battery anode

“…The synthesis of the ZnSb nanowires was carried out in a selfdesigned CVD system equipped with a graphite heater as demonstrated previously [19,20]. The detailed setup and process of the experiment can be described belowly.…”