In Situ Wrapping SiO with Carbon Nanotubes as Anode Material for High‐Performance Li–Ion Batteries

Abstract

Silicon-based material as lithium-ion anodes has attracted huge attention owing to their ultrahigh capacity. However, they usually undergo severe volume expansion over the repeated lithiation/delithiation processes and have low electronic conductivity, leading to the inferior cycling stability and the poor rate capability. Here, an in-situ growth of carbon nanotubes (CNTs) on the surface of SiO composite was prepared and then encapsulated by the amorphous carbon derived from high softening point pitch. SEM and TEM studies show that SiO was firmly wrapped with CNTs and well coated with the amorphous carbon. Meanwhile, nitrogen adsorption-desorption measurement indicated the prepared composite SiO@CNTs/C was hierarchical pore structure, which can shorten the lithium-ion transport pathway and enhance the structural stability. The prepared SiO@CNTs/C exhibited an excellent long-term cycling stability (a high reversible specific capacity of 821.7 mAh g À 1 , and a high capacity retention of 95.9% to the 3rd cycle after 200 cycles), and prominent rate capacity, indicating the great potential of SiO@CNTs/C anode for practical application.[a] Dr.

Facile Spray‐Drying Synthesis of Dual‐Shell Structure Si@SiOx@Graphite/Graphene as Stable Anode for Li‐Ion Batteries

“…To investigate the lithium‐ion storage in SGGr, cyclic voltammetry is conducted for the first five cycles at a scan rate of 0.1 mV s −1 . As shown in Figure a, two broad peaks at 1.56–1.7 V and 0.37–0.58 V occur in the first cathodic sweep but disappear in the subsequent cycles, which is attributed to the decomposition of the electrolyte additive fluoroethylene carbonate (FEC) and the formation of SEI, respectively [11a,16]. For the following cycles, the reduction peak at 0.18 V is attributed to the lithium‐ion insertion into graphite/graphene, and the sharp reduction peak <0.1 V corresponds to the transformation from crystalline Si to amorphous Si (Si → Li x Si) [11b,17].…”

Cross-Linked Sodium Alginate–Sodium Borate Hybrid Binders for High-Capacity Silicon Anodes in Lithium-Ion Batteries

“…According to the EIS spectra and the following equations, the diffusion coefficient of a lithium ion ( D Li + ) was calculated as follows where R is the molar gas constant, F is the Faraday constant, T is the Kelvin temperature, n is the number of charge transfer (for lithium-ion batteries, n = 1), A is the surface area of the electrode (simplified as the area of the electrode sheet, 1.13 cm 2 ), C is the concentration of Li + , σ w is the Warburg impedance coefficient, Z ′ is the real impedance, and ω is the angular frequency …”

“…Lithium-ion batteries have the characteristics of high output potential, little memory effect, high energy density, and long cycling life. − They are widely applied in 3C digital products, electric vehicles, aerospace, massive-scale energy-storage stations, and other fields. − With the improving requirements of the higher energy density, the commercial anodes (graphite and Li 4 Ti 5 O 12 ) could not meet the demand for lithium-ion batteries. In this case, silicon with ultrahigh theoretical specific capacity (4200 mAh·g –1 ) and relatively low potential (∼0.4 V vs Li/Li + ) is considered one of the most competitive candidates. − However, a silicon anode expands dramatically during the alloying process with Li, which would lead to chalking of the anode material and evenly collapse of the anode structure.…”

Adina Rubella‐Like Microsized SiO@N‐Doped Carbon Grafted with N‐Doped Carbon Nanotubes as Anodes for High‐Performance Lithium Storage

“…f ) Comparison of cycle performances between SiO@NC-NCNTs and previously reported Si-based anodes. [41][42][43][44][45][46][47][48]…”

“…e) Rate capabilities of SiO@NC-NCNTs, SiO@NCNTs, and pristine SiO electrodes. f ) Comparison of cycle performances between SiO@NC-NCNTs and previously reported Si-based anodes [41][42][43][44][45][46][47][48].…”