Researchers from Korea and Germany have prepared 3D silicon/carbon (Si@C) core–shell anodes for use in Li-ion batteries. With carbon coating and laser structuring, the anode materials exhibit high specific capacity (>1200 mAh g−1 over 300 cycles); good rate capability (1170 mAh g−1 at 8 A g−1); and stable cycling. A paper on their work is published in the Journal of Power Sources.
Practical application of silicon anodes for lithium-ion batteries has been mainly hindered because of their low electrical conductivity and large volume change (ca. 300%) occurring during the lithiation and delithiation processes. Thus, the surface engineering of active particles (material design) and the modification of electrode structure (electrode design) of silicon are necessary to alleviate these critical limiting factors.—Kim et al.
The team prepared the Si@C particles by thermal decomposition; subsequent three-dimensional (3D) electrode structures with a channel width of 15 μm were incorporated using a laser ablation process.
The researchers said that the morphology of the core–shell active material combined with 3D channel architecture minimizes the volume expansion by utilizing the void space during the repeated cycling.
Jung Sub Kim, Wilhelm Pfleging, Robert Kohler, Hans Jürgen Seifert, Tae Yong Kim, Dongjin Byun, Hun-Gi Jung, Wonchang Choi, Joong Kee Lee (2015) “Three-dimensional silicon/carbon core–shell electrode as an anode material for lithium-ion batteries” Journal of Power Sources Vol.279:13–20, doi: 10.1016/j.jpowsour.2014.12.041