Boosting Ultrafast Lithium Storage Capability of Hierarchical Core/Shell Constructed Carbon Nanofiber/3D Interconnected Hybrid Network with Nanocarbon and FTO Nanoparticle Heterostructures

Abstract

The aim of the study involves accelerating ultrafast electrochemical behavior of lithium‐ion batteries (LIBs) by proposing hierarchical core/shell heterostructure of carbon nanofiber (CNF)/3D interconnected hybrid network with nanocarbon and fluorine‐doped tin oxide (FTO) nanoparticles (NPs) via a one‐pot process of horizontal ultrasonic spray pyrolysis deposition. This is constructed via a pyrolysis reaction of ketjen black forming 3D interconnected FTO NPs covered with nanocarbon network on CNF. It offers fast electrical conductivity to the overall electrode with improved Li ion diffusion due to decreased size effect and relaxed structural variation of FTO NPs via nanocarbon network, leading to high discharge capacity (868.7 mAh g−1 after 100 cycles) at 100 mA g−1 and superior rate capability. Nevertheless, at extremely high current density (2000 mA g−1), significant ultrafast electrochemical performances with reversible discharge capacity (444.4 mAh g−1) and long‐term cycling retention (89.9% after 500 cycles) are noted. This is attributed to the novel effects of 3D interconnected hybrid network accelerating receptive capacity of Li ions into the FTO NPs via nanocarbon network, delivery of formed Li ions and electrons by hybrid network with FTO NP and nanocarbon, and prevention of FTO NP pulverization from CNFs via nanocarbon network. Therefore, the proposed heterostructure holds significant promise for effective development of ultrafast anode material for enhancing the practical applications of LIBs.

Surface functional group‐tailored B and N co‐doped carbon quantum dot anode for lithium‐ion batteries

“…Figure 5A shows the Nyquist plots of the N‐CQD, 0.1BN‐CQD, 0.5BN‐CQD, and 1.0BN‐CQD electrodes with an equivalent circuit model. The Nyquist plot can be divided into a semicircle region and an inclined line 36 . First, the semicircle in the high‐frequencies region implies the charge transfer resistance, which corresponds to the interfacial resistance between the electrolyte and electrode.…”

Surface Engineering of Carbon via Coupled Porosity Tuning and Heteroatom‐Doping for High‐Performance Flexible Fibrous Supercapacitors

“…Further, the CV curves obtained at scan rates of 0.5, 1.0, 3.0, and 5.0 mV s −1 (Figure 8b−d) clearly demonstrate the synergistic effects of porosity tuning and heteroatom codoping upon the overall energy storage mechanism. These CV curves can be divided into distinct pseudocapacitive ( k 1 v ) and ion‐diffusion ( k 2 v 1/2 ) areas in accordance with Equation (3): [ 38–40 ] …”

Multi-layered composite electrodes of high power Li4Ti5O12 and high capacity SnO2 for smart lithium ion storage

“…We further explored capacitive-and diffusion-controlled contributions to better understand electrode dynamics at increasing charge/discharge rates in the CV plots in Figures 5a-c using Equation ( 2). [48][49][50]…”

“…Equation ( 2) is usually applied for very high specific area materialstypically nanomaterialswhere fast surface reactions (sometimes termed "pseudocapacitance" faradic reactions) can make a significant contribution to capacity. [51,52] The LTO and SnO2 had mean diameters of 80 nm and 50 nm respectively, and suggested the use of Equation ( 2) may be applicable. pseudocapacitve effect ensured higher deliverable capacities at increasing rates.…”