Enhanced Capacity and Cycle Stability of a Pomegranate-Like Si/rGO Composite Anode by Electrostatic Self-Assembly and Spray-Drying Processes

Abstract

Si is considered one of the most promising anodes for lithium-ion batteries due to its ultrahigh theoretical capacity and abundant resource reserves. However, the poor conductivity and large volume expansion of silicon-based anode materials seriously affect their charge−discharge efficiency and cycling stability. In this study, the dispersion of Si nanoparticles and graphene oxide (GO) is atomized into small droplets, followed by electrostatic self-assembly, spray-drying, and high-temperature annealing to obtain the pomegranate-like Si/rGO composite (ES-Si/rGO) with a concentrated size of ∼2 μm. It is noteworthy that the preparation is under mild conditions and easy to scale up. As a result, ES-Si/rGO shows a high rate performance at wide current densities and maintains a reversible capacity of 969.3 mAh g −1 after 200 cycles at 500 mA g −1 . The compact rGO improves the electrical conductivity and slows down the structure deterioration. This work is of great potential toward the scalable preparation of silicon-based anodes.

Flexible Silicon/Titanium Dioxide/Reduced Graphene Oxide Self-Standing Electrode with High Performance and High Stability for Lithium-Ion Batteries

“…The electrochemical characteristics of the self-standing electrodes were examined via CR2032-type coin cells at room temperature of ∼25 °C. The details of cell preparation and measurements were included in our previous work . In short, lithium metal foil, LiPF 6 solution (1 M), and polypropylene film (Celgard 2400) served as the reference electrode, electrolyte, and diaphragm, respectively.…”

“…The details of cell preparation and measurements were included in our previous work. 39 In short, lithium metal foil, LiPF 6 solution (1 M), and polypropylene film (Celgard 2400) served as the reference electrode, electrolyte, and diaphragm, respectively. The electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) were measured using an electrochemical workstation (CHI660D) at a scanning of 0.1 mV s −1 .…”

Facilely Fabricating V2O3@C Nanosheets Grown on rGO as High-Performance Negative Materials for Lithium-Ion Batteries by Adjusting Surface Tension

“…So, the exploration of novel negative materials plays a significant function in the further evolution of LIBs. In past decades, a large number of studies on novel anode materials involving alloying reaction and conversion reaction type have been carried out because of their superlarge capacity (two to eight times that of graphite). − Nevertheless, the large volume expansion leads to continuous capacity attenuation, which is still a huge obstacle to their large-scale application. − The insertion reaction-type anode materials may still be the most common successful mechanism in the history of LIBs due to the small volume change, high reversibility, and excellent stability.…”