Etching Asymmetric Germanium Membranes with Hydrogen Peroxide for High‐Capacity Lithium‐Ion Battery Anodes

Abstract

Germanium (Ge) is deemed as one of the most promising alloying anodes for rechargeable lithium‐ion batteries (LIBs) due to its large theoretical capacity, high electrical conductivity, fast lithium‐ion diffusivity, and mechanical robustness. However, Ge‐based anodes suffer from large volume changes during lithiation and delithiation, which can deteriorate their electrochemical performance rapidly. Herein, the large volume change issue is effectively addressed using an asymmetric membrane structure that is prepared using a phase‐inversion method in combination with hydrogen peroxide etching and surface coating. The asymmetric Ge membrane etched by ≈30 wt% H2O2 at 90 °C for 30 s demonstrates a capacity retention higher than 80% in 50 cycles at 160 mA g−1. Coating the H2O2‐etched Ge membrane with carbonaceous membranes can further improve the retention up to 95% in 50 cycles at 160 mA g−1, whereas ≈100% capacity of 700 mAh g−1 can be maintained in 170 cycles at 400 mA g−1. A combination of electron microscopy, spectrophotometry, and X‐ray analyses confirms the electrochemical performance of asymmetric Ge membranes as the LIB anode can be significantly affected by membrane geometry, the duration of hydrogen peroxide etching, carbonaceous membrane coating, and Ge concentration.

Antimony nanobelt asymmetric membranes for sodium ion battery

“…Quite a few strategies have been proposed to accommodate the large volume change of antimony-based alloy anodes, most of which focus on nano-structuring, compositing, alloying, as well as developing new binders and electrolyte additives [10,[13][14][15]. Recently, asymmetric membrane structure has been adopted by our laboratory for the first time to alleviate the severe volume expansion of highcapacity anodes in LIBs, such as Si, Ge and Sn nano/micron particles [16][17][18][19][20][21]. In this study, antimony nanobelts embedded in carbonaceous asymmetric membranes are synthesized, characterized and employed as the alloy anode material for high capacity/performance SIBs.…”

Innovative and Economically Beneficial Use of Corn and Corn Products in Electrochemical Energy Storage Applications

“…Therefore, tremendous effort has been made to explore the fundamental basics of high-capacity and high-energy electrode materials and many strategies have been proposed to conquer the obstacles of boosting energy density of the batteries. − One strategy is to reduce particle size to nanoscale to alleviate mechanical strain. For example, Liu et al found that, during the first lithiation process, the nanoparticles with diameters less than 150 nm undergo volume expansion without fracturing or cracking, suggesting that nanoparticles can tolerate huge volume change .…”

Green, Template-Less Synthesis of Honeycomb-like Porous Micron-Sized Red Phosphorus for High-Performance Lithium Storage

“…22 Therefore, to meet the production and market demand for energy storage devices, micron-sized red phosphorus with high cycling stability are eagerly expected for practical application. 23,24 To this end, structural design and material engineering are regarded as an effective strategy to accommodate the intrinsic obstacles of RP. In various structures, the porous structure has been extensively designed in nanomaterials, as it owns a large amount of free pores, so its inward expansion could effectively buffer the particle-level volume change of the whole particle during cycling.…”

“…In addition, when the active particles are reduced to nanometer size, the bulk packing density and stability will be compromised, and the energy consumption and cost will be greatly increased . Therefore, to meet the production and market demand for energy storage devices, micron-sized red phosphorus with high cycling stability are eagerly expected for practical application. , …”