Improved Electrochemical Performance of a Ge_xSi_1−xAlloy Negative Electrode for Lithium-Ion Batteries

Abstract

A Ge x Si 1¹x alloy electrode is useful for addressing the shortcomings of a Si negative electrode for lithium-ion batteries. To further improve the electrochemical performance of a Ge x Si 1¹x negative electrode, a film-forming additive and the formation of a composite with LaSi 2 were applied. A Ge 0.1 Si 0.9 electrode exhibited better cyclability in the additive-containing electrolyte with a discharge capacity of 1240 mA h g ¹1 at the 400th cycle. In addition, a Ge 0.1 Si 0.9 /LaSi 2 composite electrode showed better cycle performance than a Ge 0.1 Si 0.9 electrode.

Si and Ge‐Based Anode Materials for Li‐, Na‐, and K‐Ion Batteries: A Perspective from Structure to Electrochemical Mechanism

“…For micron‐sized particles, 1020 mAh g −1 are obtained after 100 cycles for Si 0.9 Ge 0.1 and 1300 mAh g −1 for Si 0.5 Ge 0.5 . Domi et al used a VC containing electrolyte and obtained 1240 mAh g −1 after 400 cycles (52% capacity retention) for Si 0.9 Ge 0.1 and an enhanced performance in Si 0.9 Ge 0.1 /LaSi 2 (50:50 wt%), the presence of LaSi 2 improves the mechanical and electrical properties as previously observed for Si electrodes . Capacities between 1200–2120 mAh g −1 in a whole Si 1− x Ge x range have been obtained for sputtered amorphous nanofilms, two different Li extraction mechanism were identified; a single‐phase for Si‐rich phases and a two‐phase for Ge‐rich phases …”

Effect of Element Substitution on Electrochemical Performance of Silicide/Si Composite Electrodes for Lithium-Ion Batteries

“…These include reducing the size of the Si particles to prevent generation of stress, , doping Si with impurities, such as boron and phosphorous, to suppress the Si-to-Li 15 Si 4 phase transition, and/or increasing its electrical conductivity, ,− and preparing lithium silicides to decrease the relative volume change in Si during charge–discharge cycles . Other approaches involve coating Si with conductive materials to lower the electrical resistivity , or synthesizing Si-based alloys to enhance the stability of the electrode structure during cycling. − Moreover, film-forming additives or ionic liquid electrolytes have been utilized for the construction of an optimal solid–electrolyte interphase. − Lastly, composites have been prepared to improve the mechanical properties …”

Simple synthesis of SiGe@C porous microparticles as high-rate anode materials for lithium-ion batteries

“…Moreover, it shows a higher lithium ion diffusivity (400 times higher than Si) and better electrical conductivity (104 times higher than Si). [16][17][18][19][20] Similarly, Ge suffers a volume expansion as large as 270% during the lithium-ion insertion. 21,22 Moreover, the high cost and low abundance of Ge hinder its commercialization.…”