A Hierarchical Si/C Nanocomposite of Stable Conductive Network Formed Through Thermal Phase Separation of Asphaltenes for High‐Performance Li‐Ion Batteries

Abstract

Silicon is one of the most promising anode materials for lithium‐ion batteries. However, the huge volume change of silicon during lithiation/delithiation triggers continuous growth of solid‐electrolyte interphase, loss of conductive contacts and structural collapse of the electrode, which causes a rapid deterioration of battery capacities. Inspired by the polyaromatic molecular nature and phase separation of asphaltenes in bitumen during thermal cracking, a hierarchical Si/C nanocomposite of robust carbon coatings and a firmly connected carbon framework on the silicon surface is synthesized by controlling the concentration of asphaltenes as carbon source and hence desired phase separation during the subsequent carbonization. The electrode made using this special Si/C nanocomposite exhibits a high reversible capacity of 1149 mAh g−1 after 600 cycles with a capacity retention of 98.5% and the operation ability at a high mass loading over 10 mg cm−2 or an area capacity of 23.8 mAh cm−2, which represents one of the highest area capacities reported in open literature but with much more stable and prolonged operations. This simple and efficient strategy is easy to scale up for commercial production to meet the rapid growth of the electric vehicle industry.

Activating bulk nickel foam for the electrochemical oxidization of ethanol by anchoring MnO2@Au nanorods

“…Compared with bare Ni, the Ni 2+ peak in Ni 2p 3/2 for both Ni-MnO 2 and Ni-MnO 2 @Au was positively shifted by 0.4 eV, suggesting the electron transfer from Ni to MnO 2 , and generating an electron-deficient surface on the nickel foam. 21,22 Additionally, the integrated areas of peak Ni 0 in Ni 2p 3/2 for both Ni-MnO 2 and Ni-MnO 2 @Au were smaller than that of bare Ni nickel foam, indicating that more Ni 0 in the nickel foam was converted to active Ni 2+ after anchoring MnO 2 or MnO 2 @Au, facilitating the generation of more reactive NiOOH sites during the EOR process. 21 The electron transfer between the related components was also manifested by comparison of the Mn 2p 3/2 spectra (Fig.…”

“…Surface modification by grafting nanosized structures is a very effective strategy for improving the catalytic performance of the bulk metal. 21,22 For example, anchoring nanosized V 2 O 3 on bulk nickel metal can greatly boost its hydrogen evolution activity. 21 The catalytic activity of bulk molybdenum (Mo) substrate can be also enhanced by the growth of a nanostructured Mo 2 C layer.…”

Design and Construction of Porous Silicon Materials as Stable Anodes for Lithium-Ion Batteries

“…In the subsequent cycles, severe volume variation will lead to particle fragmentation, loss of electrical contact between the active material and the collector, and unstable solid electrolyte interphase (SEI) film . Besides, silicon as a semiconductor material has poor electrical conductivity. , These problems have held back its application in LIBs.…”

“…17 Besides, silicon as a semiconductor material has poor electrical conductivity. 18,19 These problems have held back its application in LIBs.…”

Recent Progress and Prospects of Pitch-based Carbon Anodes for Alkali Metal-ion (Li/Na/K) Batteries

“…To date, various materials have been applied as anode materials for alkali metal-ion (Li/Na/K) batteries, such as carbonaceous materials, [34][35][36][37] alloy materials, [38][39][40] metal oxides/sulfides, [41][42][43] and organic materials, [44][45][46] among which carbonaceous materials are regarded as the best promising anode candidates due to the low cost, abundant resource, and environmental friendliness. Amorphous carbon as a branch of carbonaceous anode materials, such as soft carbon and hard carbon, has received more attention from research scholars.…”