Sintesis Nanosilikon Menggunakan Metode Hidrotermal dari Sekam Padi sebagai Anoda Baterai Litium-Ion

Abstract

The hydrothermal method is a simple synthesis method that utilizes chemical reactions in solution at a temperature of 180 0C Hydrothermal is known to be effective in producing synthesized materials with structures that are difficult to achieve by other techniques, including producing unique nanosilicon crystal structures. Silicon (Si) in silicate minerals is the most abundant element in nature after oxygen and is contained in many graminae plants, especially in rice husks. The element Si is known to be an alternative material to graphite for making lithium-ion battery anodes because it has excellent electrical properties. This study aims to utilize Si from rice-husk waste as the main material for lithium-ion battery anode using polyacrylic acid (PAA) and PAA with ethyl vinyl acetate (PAA/EVA) double binder. Si was synthesized from rice-husk ash silica gel using the hydrothermal method. The resulting hydrothermal rice husk Si has a surface area of 18.60-20.39 m2/g with a pore diameter of 1.69-8.30 nm; pore volume of 0.004 cc/g; crystalline structure reaching 52.48%; purity level reaching 99.01%; spherical morphology with an average diameter of 52.90 nm; and conductivity value reaching 2599.29 μS/cm. In the application of lithium-ion batteries, hydrothermal Si rice husk was prepared as an anode using PAA binder present in lithiation around 0.16-0.17 V and irradiation around 0.56-0.59 V, showing half circle Nyquist plot with resistance value Rct 20.1 Ω, specific capacity 1757 mAh/g, and cycle stability reaching 200. Then hydrothermal rice husk nanosilicon was also prepared using PAA/EVA double binder as anode, resulting in lithiation of about 0.21-0.22 V and dithiation of about 0.55-0.56 V, showing half circle Nyquist plot with resistance value Rct reaching 5.0 Ω, specific capacity of 1759 mAh/g, and cycle stability reaching 250 times. The presence of a PAA/EVA dual binder on the rice husk nanosilicon anode allows the specific capacity of the battery to be maintained longer than when using a PAA binder, so it has the potential to be applied to lithium ion batteries.