Amorphous Hierarchical Porous GeO_x as High-Capacity Anodes for Li Ion Batteries with Very Long Cycling Life

Abstract

Many researchers have focused in recent years on resolving the crucial problem of capacity fading in Li ion batteries when carbon anodes are replaced by other group-IV elements (Si, Ge, Sn) with much higher capacities. Some progress was achieved by using different nanostructures (mainly carbon coatings), with which the cycle numbers reached 100-200. However, obtaining longer stability via a simple process remains challenging. Here we demonstrate that a nanostructure of amorphous hierarchical porous GeO(x) whose primary particles are ~3.7 nm diameter has a very stable capacity of ~1250 mA h g(-1) for 600 cycles. Furthermore, we show that a full cell coupled with a Li(NiCoMn)(1/3)O(2) cathode exhibits high performance.

Pre-Lithiation Strategies for Rechargeable Energy Storage Technologies: Concepts, Promises and Challenges

“…In comparison to pre-lithiation with Li metal foil, also by use of SLMP, a wide variety of active materials has already been reported for pre-lithiation, e.g., Fe 2 O 3 [79], GeO x [80], TiO 2 [81], etc. After pre-lithiation, the Coulombic efficiency for these materials is significantly increased, i.e., for GeO x from ≈66% to ≈85.5% and for Fe 2 O 3 from ≈70% to ≈99.5%.…”

Tailoring the shape of amorphous nanomaterials: recent developments and applications

“…Nanoscale amorphous materials are important noncrystalline solids and are new type of advanced materials [18][19][20][21][22][23][24][25][26][27][28][29][30]. They have larger specific surface area than their bulk counterparts and therefore can show better performance and be applicable in more fields.…”

“…They found that the elastic strain limit and corresponding strength of the submicron-sized samples were about twice those of the already impressive elastic limit of bulk metallic glass samples, approaching the ideal elastic limit of metallic glasses. Because they have smaller size and better transport properties than bulk amorphous materials, amorphous nanomaterials can also be used in transistor devices [18,20] and lithium-ion batteries as electrode materials [25][26][27]30], while the bulk materials cannot.…”

Electrochemical Performance of Amorphous GeOxPowder Synthesized by Oxidation of NaGe Serving as an Anode for Lithium Ion Batteries

“…In addition, amorphous GeO x was synthesized by a wet chemical procedure and showed good cycle performance with less irreversible capacity of first lithiation and delithiation. 12 Recently, we have successfully synthesized amorphous GeO x (x < 1) with very short time of 2 hour by solution process. The process is that NaGe of Zintl phase was simply oxidized by isopropyl alcohol at room temperature and washed with distilled water.…”