Biomimetics‐Inspired Architecture Enables the Strength–Toughness of Ultrahigh‐Loading Silicon Electrode

Abstract

AbstractSilicon (Si), as one of the most promising anode candidates, is expected to improve the energy density of Li−ion batteries due to its high specific capacity (≈4200 mAh g−1). However, the cyclic performance of Si anode is unsatisfactory for practical usage due to its inadequate toughness when exceeding the mass loading beyond 2 mg cm−2, which triggers unceasing electrode breakage. Here, a biomimetic Si electrode is created by interconnecting vertically aligned graphene oxide sheets with conductive carbon nanotubes (AGO−Si/C). Unlike reported structures, the AGO−Si/C electrode exhibits superior interlaminar toughness owing to its unique crumpling architecture of reversible interlayer slipping. The elastic structure releases the accumulative lithiation stress of Si nanoparticles to address the degraded inactivation. Thus, the AGO−Si/C electrode shows long−lived cycles by toughening the structure, allowing the fabrication of very thick loading (4.1 mg cm−2) with an impressive areal capacity of 10.0 mAh cm−2. This discovery offers an easily scalable method for graphite/Si anode with high areal capacity that exceeds the commercial−level of 5 mAh cm−2.