Cowpea-like N-Doped Silicon Oxycarbide/Carbon Nanofibers as Anodes for High-Performance Lithium-Ion Batteries

Abstract

Silicon oxycarbide (SiOC) is considered as a potential anode material in lithium-ion batteries because of its high theoretical capacity and good structural stability. Despite many such assets, its low electronic conductivity causes poor rate capability and rapid attenuation of capacity. Herein, we report the fabrication of cowpea-like N-doped carbon nanofiber-encapsulated SiOC spheres (SiOC/C NFs) in which the Si−N bridging is introduced into SiOC. Our method not only demonstrates an improved electronic conductivity and a shortened ionic diffusion distance but also prevents agglomeration by avoiding direct contact with the electrolyte. As anode materials for lithium-ion batteries, this SiOC/C NF material delivers a high reversible capacity (707 mA h g −1 at 0.1 A g −1 after 100 cycles), a good rate performance (468 mA h g −1 at 1.6 A g −1 ), and an excellent cycling stability (570 mA h g −1 at 0.4 A g −1 after 800 cycles). Moreover, the full cell of LiFePO 4 // SiOC/C NFs exhibits excellent electrochemical properties, which demonstrates its prospect of great potential as an anode material for high-performance lithium-ion batteries.

Electrochemical Performance of Polymer-Derived Silicon-Oxycarbide/Graphene Nanoplatelet Composites for High-Performance Li-Ion Batteries

“…By forming a percolation network, carbonaceous materials boost the electrical conductivity of the system as well as enhance Li storage capacity and electron transfer kinetics. Numerous studies have focused on the incorporation of carbon materials into the SiOC material system, including carbon nanotubes, , graphite, − graphene nanoplatelets (GNPs), − graphene oxide, , reduced graphene oxide, − and carbon nanofibers. , Various processing methods have been employed to develop 2D carbonaceous-based SiOC anodes, like ball milling, physical mixing, sol–gel infiltration, precursor infiltration, in situ reaction, and electrospinning. ,− ,, …”

“…Numerous studies have focused on the incorporation of carbon materials into the SiOC material system, including carbon nanotubes, 27,28 graphite, 29−32 graphene nanoplatelets (GNPs), 33−38 graphene oxide, 39,40 reduced graphene oxide, 41−43 and carbon nanofibers. 44,45 Various processing methods have been employed to develop 2D carbonaceous-based SiOC anodes, like ball milling, physical mixing, sol−gel infiltration, precursor infiltration, in situ reaction, and electrospinning. 27,[34][35][36][37]43,45 However, a few recent reports on current collectors suggested that the surface roughness, structure, wettability, flexibility, compressibility, safety, and weight of the collector are important factors that need to be considered.…”

“…44,45 Various processing methods have been employed to develop 2D carbonaceous-based SiOC anodes, like ball milling, physical mixing, sol−gel infiltration, precursor infiltration, in situ reaction, and electrospinning. 27,[34][35][36][37]43,45 However, a few recent reports on current collectors suggested that the surface roughness, structure, wettability, flexibility, compressibility, safety, and weight of the collector are important factors that need to be considered. 46,47 A typical Li-ion battery uses copper foil as the conventional metal current collector, which outweighs the overall weight of the cells.…”

Hierarchical 1D/2D V3S4@N, S-Codoped rGO Hybrids as High-Performance Anode Materials for Fast and Stable Lithium-Ion Storage

“…Ordinarily, the electrode materials determine the electrochemical performance of LIBs, e.g., energy and power density, cycling lifetime, etc . Therefore, current studies are mainly focused on developing advanced anode materials that possess fast ion transportation dynamics and robust structure to replace the widely used commercial graphite anodes and satisfy the current market demand. − Nowadays, based on different Li-storage mechanisms, most anode materials can be classified into three types: insertion-type anodes (hard carbon, graphite), alloy-type anodes (Sn, Bi, Sb), and conversion-type anodes (WS 2 , MoS 2 , VN). , Typically, compared with the others, conversion reactions are able to avoid huge volume swelling and manifest large theoretical specific capacity (ranging from 500 to 1000 mA h g –1 ). , …”

“…5−7 Nowadays, based on different Li-storage mechanisms, most anode materials can be classified into three types: insertiontype anodes (hard carbon, graphite), alloy-type anodes (Sn, Bi, Sb), and conversion-type anodes (WS 2 , MoS 2 , VN). 8,9 Typically, compared with the others, conversion reactions are able to avoid huge volume swelling and manifest large theoretical specific capacity (ranging from 500 to 1000 mA h g −1 ). 10,11 Among these conversion-type anode materials, transitionmetal sulfides (TMDs) have attracted widespread attention in terms of energy storage due to their unique graphite-like layered structure and special physical and chemical properties.…”