Well-dispersed double carbon layers coated on Si nanoparticles and the enhanced electrochemical performance for lithium
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Well-dispersed double carbon layers coated on Si nanoparticles and the enhanced electrochemical performance for lithium ion batteries Yi Man1 · Rong‑ying Lin1 Received: 3 February 2020 / Accepted: 21 July 2020 © Springer Science+Business Media, LLC, part of Springer Nature 2020
Abstract The amorphous carbon was coated on the surface of the nano-silicon with citric acid by a simple mechanical stirring in water bath method and high temperature pyrolysis method, and then the carbon-coated silicon composite material(Si@C) was coated with polyvinyl alcohol by the secondary mechanical stirring and high temperature pyrolysis to obtain double carbon layer-coated silicon composite material (Si@C@C). The microstructure and surface morphology of Si@C@C were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The electrochemical properties of Si@C@C were investigated by constant current charge–discharge, cyclic voltammetry, and electrochemical impedance spectra techniques. The study found that the first reversible specific capacity of Si@C@C was 1669 mAh/g at the current density of 0.1 C. The specific capacity remained at 1300 mAh/g, while the capacity retention rate was 77.9% after 200 cycles. The cyclic stability of Si@C@C was higher than that of Si@C, which greatly improved the electrochemical performance of silicon-based materials as anode materials for lithium ion batteries.
1 Introduction The rapid development of new energy fields puts new demands on the energy storage materials. In the upgrading of energy storage battery, lithium ion battery has become a key research field due to its various advantages [1]. In the last two decades, lithium ion batteries have successfully dominated the portable electronics market and are on the way to mass production of electric vehicles [2]. However, even if the research develops rapidly, it still cannot meet the demand of electric vehicle market for specific capacity and energy density. Therefore, the research of new cathode and anode materials for lithium ion battery is extremely urgent. The capacity of lithium ion battery depends on the activity of lithium ion of cathode material and the ability of deintercalation lithium ion of anode material. The stability of anode and cathode in various environments determine the performance of the battery, and even seriously affect the safety of the battery. At present, the anode materials for * Rong‑ying Lin [email protected] 1
College of Chemical Engineering, Fuzhou University, 350108, Fuzhou, China
commercial lithium ion batteries are mainly graphite-based carbon anode materials, and the theoretical specific capacity of graphite is only 372 mAh/g [3], which seriously limits the further development of lithium ion batteries. Silicon is considered to be one of the most promising anode materials for the next generation lithium ion batteries due to its high theoretical capacity (4200 mAh/g [4]), abundant availability, environmental friendliness and high energy density. However, low conductivity silicon materials
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