| 초록 |
The extensive outlooks for high-energy-density anode materials in LiBs foresees Bi as an attractive candidate, favoring its ultrahigh volumetric capacity (3430 mAh cm-3) and large interlayer spacing (3.95 Å). However, Bi is vulnerable to severe volume variation impeding the stability and long lifespan. Herein, as an approach, we introduce a fine flesh-like carbon embedding densely packed seed-like Bi nanoparticles via a facile one-pot supercritical route. Acetone utilized as the carbon source decomposes under supercritical conditions and in the presence of HNO3 (surface modifier), the carbon and Bi tailors into a cucumber-inspired microstructure. A two-step calcination process was further conducted at 120 °C and 700 °C to form sturdy carbon-coated Bi. The material delivers unprecedented initial capacity (614 mAh g–1) and cyclability (337 mAh g–1 after 70 cycles at 50 mA g–1). The enhanced Li storage performance can be attributed to the balance between mix-ester-ether electrolyte, well-defined carbon layer, and nanosized Bi, which resolves for capital initial capacity loss, provides continuous electronic conductivity, and improves kinetic reactions. |
