Pulsed current electrodeposition parameters to control the Sn particle size to enhance electrochemical performance as anode material in lithium ion batteries

Abstract

Abstract The Sn nanoparticles were synthesized through pulsed current electrodeposition in an acidic electrochemical bath containing polyvinylpyrrolidone (PVP) in order to control the electrodeposition rate of Sn reduction on copper collector electrode. The anode prepared at electrochemical bath containing PVP concentration of about 10 g·L−1 showed highest discharge capacity and cycleability as two main criteria in lithium ion batteries. Also, the pulsed current characteristics such as frequency and current density were investigated and 10 Hz and 20 mA·cm− 2, respectively, are obtained as the optimum parameters. The synthesis of Sn nanoparticles in such media was successfully developed. The sizes and morphologies of NPs were characterized by X-ray diffraction and scanning electron microscopy. Our findings indicated that the nanosized spherical particles with a diameter ranging from 80 to 100 nm could be formed at optimum concentration. The discharge capacity of synthesized Sn nanoparticles was obtained about 1350 mAh g− 1, indicating a 32% increase compared to the synthesized Sn particles with constant current electrodeposition method. Additionally, the discharge capacity of around 550 mAh g–1 is obtained in the 50th cycle, which shows an appropriate cycleability compared to the Sn film electrode prepared by a constant current electrodeposition. The discharge capacities obtained indicated a considerable improvement compared to similar works. The particles size of coated Sn on collector electrode is resulted from interplay between the rate of nucleation and growing rate of particles. PVP affects the kinetic of electrodeposition through surface capping and complexing of Sn2 + species.