Effects of In Situ Graphitic Nanocarbon Coatings on Cycling Performance of Silicon-Flake-Based Anode of Lithium Ion Battery

Abstract

We coated graphitic nanocarbons by thermal chemical vapor deposition (CVD) on silicon flakes recycled from the waste of silicon wafer manufacturing processes as an active material for the anode of lithium ion battery (LIB). Ferrocene contains both iron catalyst and carbon, while camphor serves as an additional carbon source. Water vapor promotes catalytic growth of nanocarbons, including carbon nanotubes (CNTs), carbon fibers (CFs), and carbon films made of graphitic carbon nanoparticles, at temperatures ranging from 650 to 850 °C. The container of silicon flakes rotates for uniform coatings on silicon flakes of about 100 nm thick and 800–1000 nm in lateral dimensions. Due to short CVD time, besides CNTs and CFs, surfaces of silicon flakes deposit with high-density graphitic nanoparticles, especially at a low temperature of 650 °C. Nanocarbon coatings were characterized by SEM, EDX, ESCA, and Raman spectroscopy. Half-cells were characterized by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and retention of capacity in discharge/charge cycling. Silicon-flake-based anode with nanocarbon coatings at both 650 and 850 °C exhibited capacity retention of 2000 mAh/g after 100 cycles at 0.1 C, without needing any conductivity enhancement material such as Super P.

Application of power battery under thermal conductive silica gel plate in new energy vehicles

“…According to Eqs. ( 4)- (5), assuming that the radiation heat transfer between the power battery and the external environment is zero, the convection heat transfer coefficient with the external environment is 5W m −2 •K −1 , a = 0.01593, b = 28.41552, the average heat production rate of the square iron-shell lithium iron phosphate power battery at the 4C discharge rate is 27.81 W.…”

“…The power battery module is the core component of the energy supply, and its safety assessment, management, and protection have received extensive attention in recent years 4 . Among various rechargeable batteries such as lead-acid, sodium-sulfur, and lithium-ion batteries, lithium-ion batteries have many merits, such as elevated energy density, substantial specific capacity, minimal environmental impact, stable functionality, and prolonged cycle life 5 . Therefore, it is also considered the most suitable power source for new energy vehicles 6 .…”

New Chemical Synthesis Strategy To Construct a Silicon/Carbon Nanotubes/Carbon-Integrated Composite with Outstanding Lithium Storage Capability

“…Novikov et al 28 used ferrocene as an effective catalyst to convert CO 2 into CNTs and revealed the nucleation mechanism of CNTs. Tzeng et al 29 synthesized silicon/carbon nanotubes/carbon fibers (Si/ CNTs/CFs) composites using ferrocene as a catalyst. The Si/ CNTs/CFs anode exhibited good rate capability.…”

Effects of Pyrolysis on High-Capacity Si-Based Anode of Lithium Ion Battery with High Coulombic Efficiency and Long Cycling Life

“…Many attempts have been reported to overcome barriers against a long-life silicon-based anode for lithium-ion battery. Chemical passivation layers were coated on the surface of the silicon powder followed by an electrically conductive carbon layer [ 6 , 7 , 8 , 9 ]. The chemical passivation layers reduce undesirable reactions between silicon surface and the electrolyte, and thus enhance the coulombic efficiency and cycling life.…”