Pengaruh Variasi Suhu Kalsinasi Terhadap Performa Elektrokimia Pada Material Katoda LiFeSi0,03P0,97O4/C

Katoda LiFePO4 (LFP) merupakan salah satu komponen penting dari baterai lithium ion. Sintesis katoda LFP coating karbon telah dilakukan dengan menggunakan metode solid state reaction pada suhu kalsinasi 800℃ dengan variasi karbon 11 wt%. LFP dengan doping silicon (Si) juga telah dilakukan dengan konsentrasi x=0,03 pada LiFeSixP1-xO4/C. Penelitian ini bertujuan untuk mengetahui pengaruh variasi suhu kalsinasi terhadap performa elektrokimia katoda LiFeSi0,03P0,97O4/C (LFSP/C) yang disintesis dengan menggunakan metode solid state reaction. Metode solid state reaction dipilih karena ekonomis dan prosesnya yang sederhana. Pengujian DSC-TGA (Differential Scanning Calorimetry – Thermogravimetric Analysis) dilakukan terhadap sampel yang telah selesai di-milling sebelum proses kalsinasi. Pengujian ini berfungsi untuk mengetahui variasi suhu kalsinasi yang akan diterapkan pada sampel. Karaktersasi XRD (X-ray Diffractometer) dilakukan untuk mengidentifikasi fasa yang terbentuk. SEM-EDX (Scanning Electron Microscopy – Energy Dispersive X-ray) dan TEM (Transmission Electron Microscopy) dilakukan untuk mengetahui perubahan morfologi permukaan sampel dan ukuran partikel sampel yang memiliki performa elektrokimia terbaik. Performa elektrokimia katoda LFSP/C diketahui melalui pengujian CV (Cyclic Voltammetry), CD (Charge-Discharge) dan EIS (Electrochemical Impedance Spectroscopy). Hasil XRD menunjukkan terbentuknya kristalinitas paling tinggi adalah LFSP/C 7 (LiFeSi0,03P0,97O4/C kalsinasi suhu 700oC) dengan struktur orthorombik dan space group pnma. Semakin meningkatnya suhu kalsinasi mengakibatkan ukuran partikel LFSP/C juga meningkat, namun kehomogenan sebaran karbon mengalami penurunan pada suhu 800oC yang diindikasikan karbon teroksidasi menjadi CO2. LFSP/C 7 memiliki performa elektrokimia yang paling baik ditandai dengan konduktivitas ionik dan elektrik yang tinggi yaitu 7.99 x10-4 S/cm dan 2.07 x10-5 S/cm. Kapasitas spesifik discharge yang paling tinggi diperoleh sebesar 104,21 mAh/g.=============================================================================================== LiFePO4 (LFP) cathode is one of lithium-ion battery important components. LFP cathode coating carbon (11 wt% carbon) has been synthesized using the solid-state reaction method at 800℃ calcination temperature. LFP with Si doping has also been done with a concentration of x=0,03 in LiFeSixP1-xO4/C. The purpose of this study is to determine the effect of calcination temperature variance on the electrochemical performance of the LiFeSi0.03P0.97O4/C (LFSP/C) cathode which will be synthesized using solid state reaction method. The solid-state reaction method was chosen because economical and the process is simple. The DSC-TGA (Differential Scanning Calorimetry – Thermogravimetric Analysis) test was carried out on samples that gave been milled before calcination process. This test serves to determine the variations in calcination temperature that will be applied to the sample. XRD (X-ray Diffractometer) characterization is performed to identify the phases formed. SEM-EDX (Scanning Electron Microscopy – Energy Dispersive X-ray) and TEM (Transmission Electron Microscopy) were performed to determine changes in sample morphology and particle size of samples with the best electrochemical performance. The electrochemical performance of LFSP/C cathode was known by CV (Cyclic Voltammetry), CD (Charge-Discharge) and EIS (Electrochemical Impedance Spectroscopy) tests. XRD results showed that the highest crystallinity was LFSP/C 7 (LiFeSi0.03P0.97O4/C calcined at 700oC) with an orthorombic structure and pnma space group. The increasing calcination temperature resulted in an increase in LFSP/C particle size, but the homogenity of carbon distributin decreased at a temperature of 800oC which indicated that the carbon was oxidized to CO2. LFSP/C 7 has the best electrochemical performance characterized by high ionic and electrical conductivity, namely 7.99 x10-4 S/cm and 2.07 x10-5 S/cm. The highest specific discharge capacity was obtained at 104.21 mAh/g