Chitosan grafted alginate and polyvinylpyrrolidone as the binder for porous silicon nanoparticles from coal fly ash in lithium-ion batteries

Abstract

Polymer binders are also important to overcome silicon as an anode in lithium-ion batteries (LIBs). Binder polymers with carboxylate or hydroxyl groups are used because they can bond with silicon through covalent or hydrogen bonding and reduce the formation of large volume changes during charging and discharging. The 1H NMR spectra show a new peak at 2.19 ppm, indicating the formation of cyclic compounds derived from PVP. FTIR spectra show peak adsorption at 3297 cm−1, indicating hydroxyl and amino group stretching. Adsorption at 1413 cm−1 shows COO symmetric stretching vibration. Adsorption at 1323 cm−1 shows stretching vibration in the C-N group. The adsorption at 1024 cm−1 shows C-O stretching. Adsorption at 443 cm−1 shows CH2 bond and also N-CO bending. The electrochemical performance of lithium-ion shows high capacity. The CV curve shows that the reduction peak is around 0.16 V, and the oxidation peak is around 0.38 V and 0.56 V. Nyquist plots show a small half circle indicating that the solid-electrolyte interphase layer is low on the electrode. The cycling performance shows a high initial capacity of 2912 mAh/g. It can maintain a high and good capacity until 400 cycles at 1374 mAh/g.