Silicon/Carbon Nanoparticles Assembled with Multifunction Carbon Nanotubes/Sheets as High-Performance Anode of Lithium-Ion Batteries

Abstract

Silicon as an electrode material in the lithium-ion battery application scenario has been hindered by its significant volumetric expansion and intricate synthesis processes. In this research, we have successfully synthesized Si@C/carbon nanotubes/carbon sheets (Si@C-CNTs/CS) composites by employing a simple one-pot method along with modified magnesium thermal reaction, which involves melamine to prevent high temperature. The resulting multifunctional Si@C-CNTs/CS composites demonstrate enhanced stability during volume change in silicon, resulting in both higher capacity compared to conventional carbon coating layer and improved conductivity of the materials. The results indicate that the Si@C-CNTs/CS composites exhibit a high discharge-specific capacity of up to 2981.64 mAh g−1 at 0.5 A g−1 current density and retain a discharge-specific capacity of 1487.71 mAh g−1 even after 300 cycles. Therefore, the double-layer carbon network structure of carbon nanotubes/carbon nanosheets can provide an efficient and simple preparation method for high-performance Si-base anode materials in practical applications.

Construction of honeycomb porous silicon as a high-capacity and long-life anode toward Li-ion batteries

“…The reaction of Mg 2 Si with HCl generated SiH 4 , which was prone to self-ignition in the air, thus posing a potential safety risk. 38 Possible reactions during the magnesium thermal reduction process were described as follows: 39 2Mg(g) + SiO 2 (s) = 2MgO(s) + Si(s)Si(s) + 2Mg(g) = Mg 2 Si(s)SiO 2 (s) + 4Mg(g) = 2MgO(s) + Mg 2 Si(s)Mg 2 Si(s) + SiO 2 (s) = 2MgO(s) + 2Si(s)…”

Research Progress in Cathode Catalysts for Li-CO2 Batteries

“…So Yang et al dispersed Ru and Cu onto carbon materials to form (Ru-Cu-G). Testing indicates that when used with Li-CO2 batteries, it can cycle steadily for 100 cycles at current densities of 200 mA/g and 400 mA/g and has a discharge capacity of 13698 mAh/g at a current density of 200 mA/g [7]. This not only preserved the high discharge capacity of single metal catalysts but also achieved better stability because of the synergistic effect between metals which made their nanoparticles more dispersed and less prone to aggregation.…”

“…Since Cu's exceptional catalytic capacity to remove CO2, Cu-NG onto Li-CO2 batteries was developed employing this material. This led to a discharge capacity of 14864 mA/g at an average current density of 200 mA/g and steady cycling at low overvoltage densities of 200 mA/g and 400 mA/g for 50 cycles [7]. Moreover, a layer of CuO formed on the surface of Cu during the reaction, enhancing the stability of the positive electrode and protecting its structure.…”

“…Precious metals are widely used in the field of new energy due to their high activity, selectivity, and stability [7]. Among them, Ru noble metal is a potential noble metal catalyst on the market at present, which has an outstanding ability to promote the redox of CO2.…”

“…To create Ru NG, Yang et al added Ru nanoparticles to N-doped graphene. It can perform steadily for 50 cycles at current densities of 200 mA/g and 400 mA/g and had a discharge capacity of 16743 mAh/g when applied to Li-CO2 batteries [7]. The advantages of Ru-NG are its good reversibility and electrocatalytic activity.…”