SILICON MICROPARTICLES PREPARED BY HIGH-ENERGY BALL MILLING AS ANODE FOR LITHIUM-ION BATTERIES

• Main Author: Prima Yuda, Ansor
• Format: Theses
• Language: Indonesia
• Subjects: Teknik (Rekayasa, enjinering dan kegiatan berkaitan)
• Online Access: https://digilib.itb.ac.id/gdl/view/57510
• Institution: Institut Teknologi Bandung

Although silicon has been considered the next generation anode for lithium-ion batteries, it still suffers from several challenges originating from the large volume expansion upon the lithiation and poor electrical conductivity. The repeated volume expansion leads to cracks and pulverization within the first few cycles and results in the excessive formation of the passive solid electrolyte interface (SEI) layer. The low electrical conductivity hinders the development of optimum capacity and rate capability performance. To circumvent the drawbacks, downsizing the bulk silicon into microparticles has gained attention owing to the enhanced structural stability and fast electron transfer ability. Herein, silicon microparticles were prepared by the facile and scalable high-energy ball milling from the starting material of an n-type silicon wafer. The silicon wafer was first crushed into small pieces prior to the ball milling with different milling times of 10 hours (denoted as Si-10h) and 20 hours (denoted as Si-20h). Several characterization methods were performed on the samples to verify the formation of silicon microparticles. The XRD analysis showed sharp peak patterns that confirmed the crystalline structure of silicon. The particle size distribution of Si-20h exhibited a well-defined peak centered at 2.9 ?m, whereas the Si-10h consisted of two populations at 0.34 ?m and 6.3 ?m. The morphology of the particles was analyzed by the SEM where Si-10h and Si-20h had an irregular shape, and the latter showed smaller in size. The specific surface area of Si-20h was measured by the BET analysis at 4.80 m2 g-1. As the positive electrode for half-cell of lithium-ion batteries, Si-20h performed an initial discharge capacity of 2640 mAh g-1 and maintained capacity retention of 86% after five cycles.