ALGINATE-BASED ELECTROSPUN NANOFIBER FOR SUSTAINABLE LITHIUM-ION BATTERY SEPARATOR

• Main Author: Miftahul Anwar, Ahmad
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/80225
• Institution: Institut Teknologi Bandung

The demand for Li-ion batteries is steadily increasing alongside the advancement of technology and the need for portable energy. Electric vehicles are a significant factor in driving this demand, with projections indicating that by 2025, battery waste from electric vehicles will reach a substantial figure of approximately 464,000 tons worldwide. One of the key components in Li-ion batteries is the separator, typically made from polypropylene or polyethylene. Unfortunately, these separators are not environmentally friendly and are challenging to recycle, as the current recycling processes primarily focus on recovering valuable metals from used batteries. In an effort to address the environmental issues arising from the use of conventional separators, this research introduces alginate as more eco-friendly alternative. Alginate is a polymer that can be extracted from seaweed and possesses attractive properties for use as a battery separator. The electric spinning method is employed to produce membrane separators from alginate. However, due to the challenges in electric spinning of alginate, this research also explores polymer blending with polyvinyl alcohol (PVA) to enhance its electrical spinning capabilities. Electric spinning for blending PVA and alginate is carried out by considering the parameters of humidity, collector syringe distance, voltage and solution flow rate to produce continuous fibers with few defects. Characterization using infrared, scanning electron microscope, thermal resistance, electrolyte absorption and porosity measurements were carried out to confirm the electric spinning products that had been carried out. From the fabrication carried out, a PVA-Alginate separator membrane was obtained with high porosity (75%) and good electrolyte absorption capacity, reaching 460%. In addition, the PVA-Alginate separator has a lower bulk resistance (Rb) value compared to conventional separators such as Celgard, which is commonly used in Li-ion batteries. This shows that the PVAAlginate separator can support better ion flow in the battery, which is important for better battery performance. The PVA-Alginate separator also has a higher ionic conductivity, namely 8.4 mS/cm. This value is higher than Celgard which has a conductivity of 0.18 mS/cm. This indicates that this separator can allow the movement of ions more efficiently, increasing the capacity and durability of Li-ion batteries. The PVA-Alginate separator also shows excellent stability. In tests with Linear Sweep Voltammetry, this separator has a level of stability comparable to Celgard. In fact, in a resistance test against lithium stripping plating for 1000 hours, the PVA-Alginate separator remained stable, while Celgard experienced degradation from the 200th hour. This shows that the PVA-Alginate separator has better long-term durability. The use of the PVA-Alginate separator in the LFPSeparator- Li battery produces a higher specific discharge capacity, namely 150 mAh/g, compared to the use of Celgard which only produces 130 mAh/g. The results of this research show that the PVA-Alginate separator can be fabricated by electric spinning and produce a separator with good performance for Li-ion batteries.